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V-DOSC - Allstar Show Industries Inc.

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2. 58218 8718 GROUND L GROUND R CO24 FA CO24 CO24 O2 CO24 CO24 COMM 024 C024 CO24 CO24 A A A B B B B C C E A TWN ei TERIS EN f 2 THING NINN a NCE UNININT Es TAI NNI TL JA UNES ZIMI L 2 NNN NIE he Al T ANN AE TON ESL MM AN TT e fT Tum 2 cue zn 2 Y Y Jg tu 0 17 2 2W SUB SUB SWAY 3WAY 3WAY 3WAY BWAY 3WAY 3WAY SUB SUB B 2W B 2W A SUB 3WAY 3WAY 3WAY 3WAY 3WAY 3WAY 3WAY 3WAY SUB 2W B Figure 8 Example LR System Plus Offstage Fill Configuration additional distributed front fill or stereo infill system recommended L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 22 of 158 V DOSC SYSTEM COMPONENTS LOUDSPEAKER ENCLOSURES 1 2 3 4 V DOSC Full range active 3 way loudspeaker enclosure meeting WST criteria w
3. 136 Figure The Interference Problem db etus 142 Figure 102 Comb filtering due to path length differences between sources 143 Figure 103 Destructive interference ring for line array at observation point 144 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 9 of 158 Figure 104 The effect of varying frequency and listener position M on Fresnel rings 145 Figure 105 Destructive and constructive interference rings for a line array at observation point M 145 Figure 106 Constructive interference rings for a condensed point source line array 146 Figure 107 Destructive interference rings out of beamwidth for condensed standard line arrays 147 Figure 108 Front view of V DOSC array and vertically stacked DOSC waveguides 148 Figure 109 Horn Generated 49 Figure 110 DOSC Waveguide Internal Section 49 Figure 111 Illustration of the Fresnel and Fraunhofer 150 Figure 112 Illustration of dborder and Dv flat 12 enclosure 151 Figure 113 Illustration of the v
4. DLE 53 AWAY PRESETS sce 54 SUBWOOFER TIME ALIGNMENT RECOMMENDATIONS 54 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 5 of 158 SUB LOW GAIN SCALING 5 54 SUBWOOFER PRESETS DELAY ARC 54 INFRA PRESET e n 55 AW PRESE 55 PRESET ecc 56 PRESE eem 56 5 WAY PRESETS 57 SW INFRA PRESET 57 DW PRESE 57 GENERAL GUIDELINES REGARDING SYSTEM 58 XTA DP224 V DOSC PRESETS 59 DP226 V DOSC PRESETS 60 LAKE CONTOUR V DOSG PRESETS 61 BSS FDS 366 V DOSC PRESETS pease 62 2 V DOSC COVERAGE MODELING 63 2 COVERAGE IN THE HORIZONTAL PLANE 63 2 2 COVERAGE IN THE VERTICAL PLANE 64 64 Curved EE 64 Constant Curvature V DOSC
5. 62 Table 15 Anele Strap Values oh ert tera eti aeu gehe Deb ed e E us vba deba verse eoe 110 Table 16 Weights for flown V DOSC 136 Table 17 Whirlwind W6 MASS Connector Input Output Line 137 Table CO24 W6 Pin ASSISMINGMES canisinin a a EE 138 Table 186 CO24 W6 Socket Assignments 139 Table 194 MD24 W6 Pin ASSIgEITIGIIES been teo et s to aude ee eee a etes te ue 140 Table 19b TVD24 VV6 Socket Assignments 141 Table 20 Border m Between Cylindrical Fresnel Spherical Fraunhofer 15 Table 21 Dv Vertical Coverage Angle in the Farfield Region 151 Table 22 WSF Criteria 153 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 10 of 158 INTRODUCTION The V DOSC sound reinforcement system is different We hope this manual will help you to appreciate why and to understand the basic theoretical principles behind how V DOSC works Understanding the concepts behind V DOSC and Wavefront Sculpture Technology is just as important as the many operational details related in this manual the more you understand the big picture the more effecti
6. 40 Figure 23 V DOSC PADO2a Amplifier Rack Panel eese 40 Figure 24 PAD O43 amp Tack WIEIE 41 Figure 25 PADOZa amp rack Wining D Soda ERE UNA EUR 42 Figure 26 L ACOUSTICS Amplifier Rack RK124a loaded with 4 x L ACOUSTICS LA48a amplifiers 43 Figure 27 L ACOUSTICS Amplifier Rack 4 2 10 0000000044040000000000000000000000000005 44 Figure 28 L ACOUSTICS 22a amplifier rack channel assignments and cabling 46 Figure 29 L ACOUSTICS RK1I 24a amplifier rack channel assignments and 46 Figure 30 LLACOUSTICS RKI22a amp rack channel assignments for 2 way 3 way stereo presets 47 Figure 31 L ACOUSTICS 24 amp rack channel assignments for 2 way 3 way stereo presets 48 Figure 32 CO24 Control Output Panlo etae euet 49 Figure 33 MD24 Multi Distro Panel ite cuss Dena e ee cays ea uo ue Ser oa ues 50 Figure 34 CO6 Control Output PArel io ott oi eoru Suse 50 Figure 35 Spectral balance for SUB LOW versus MID H
7. 8 38 oct aoe 2 60 50 rr Seanez 20 0 100 0 1000 0 log Frequency Hz Tine msec Figure 40 X AUX preset time alignment procedure L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 56 of 158 5 WAY PRESETS To enhance low end impact of the flown V DOSC system dV SUB subwoofers can be flown beside V DOSC with minimum physical separation and used in conjunction with ground stacked 58218 subwoofers to create a 5 way system The dV SUBs are run over the same operating bandwidth as the V DOSC low section and two preset types exist X INFRA 5W INFRA PRESET The 5W INFRA preset features identical operating bandwidths for the V DOSC low section and dV SUBs 60 200 Hz while ground stacked SB218s are crossed over at 60 Hz in INFRA mode 25 60 Hz Given the optimized V DOSC LF shelving eq plus the additional contribution of the dV SUBs the impact of the flown system is significantly enhanced INFRA preset is intended for configurations where 5 2 185 are ground stacked and dV SUBs are flown beside V DOSC in a closely coupled configuration For 5W INFRA preset AUX SUB drive can be implemented using the 58218 DELAY ARC 60 Hz 58218 LCR 60 Hz presets subs with positive polarity 5W INFRA PRESET Align SB218 peakl dip2 peak2 with dV SUB V DOSC low section Transfer Function Nag dB volts volts 8 38 Response voite gt
8. n LL E D LI a 10 INTRODUCTION roiroi _____ T WAVEFRONT SCULPTURE TECHNOLOGY FUNDAMENTALS sssssssssscsssssssssssssssssssssssssscssescssseees T THE SOUND REINFORCEMENT PROBLEM cccccsccsssssssssssssssssssssesssssessssessesssssssssssssessessessess T WAVEFRONT SCULPTURE TECHNOLOGY BACKGROUND c ccsccsccssssssssssessesssssssssssssesseeee 12 V DOSC THE cs 14 V DOSC TRAINING AND QUALIFICATIONS cssssssssssssssesscsscsssssssssssssussssscsscssssscssssusssssussessecsccseeees 18 QUALIFIED V DOSC TECHNICIAN QVT 18 CERTIFIED V DOSC ENGINEER CVE ccsccssssssssssssssssssssssesssssscssssssssssessessessessessesssssssessessesees 18 THE V DOSC SYSTEM STANDARD 19 V DOSC SYSTEM COMPONENTS sssssssssssssssssssssssssessssssssssesssssssssscssssssscsscssssussesssssssessesssssssessee 23 LOUDSPEAKER ENCLOSURES 23 RIGGING ACCESSORIEG ccccccsscsccscesssscssesscssscessossecsssersessssessessesessessecessorsessssersessesessessessseerses 24 SUBWOOFER ENCLOSURES ccccccsssscsssssssssssssssessesssssssssessssesssssessssessessssessessssessesssssssessesssessees 26 SUBWOOFER RIGGING ACCESSORIES cccsssscsssssssesssssssessessssessesssssssessessssecsessssesssssssessesseeess 26 AMPLIFICATION 27 222220524 27 SIGNA
9. 3 TA T4 backline 3 Enter backline delay 1 R arc radius i eee a 1 i tool iauumuamalnas Paral Figure 80 Geometric coordinates for the SUB ARC utility spreadsheet in ARRAY2004 Figure 81 Large format arena configuration 4 delay taps Rammstein World Tour 2004 5 Black Box Music L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 103 of 158 Figure 83 Large format stadium configuration Red Hot Chili Peppers 2004 European Tour Rat Sound L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 104 of 158 3 6 COMPLEMENTARY FILL SYSTEMS For flown V DOSC configurations additional speakers are typically necessary to cover center fill front fill or offstage fill requirements and delay systems may be required for large format festival or stadium sound reinforcement Apart from providing added coverage an important sound design consideration for complementary fill systems is audience image localization especially for theatrical applicatons where the addition of centre cluster front fill and underbalcony delay systems can help focus audience attention to the action onstage Note All L ACOUSTICS loudspeakers and OEM factory presets are specifically designed to have a compatible sonic signature For this reason L ACOUSTICS enclosures provide the best complementary fill system solutions and are recommended for use with V DOSC 3 6 1 FRONT FILL In m
10. EE SS ee ee ae ARCS 58118 LO 38 i 090 a a i Ru E 2 112 FILL 44 i a a a Ss fee mcos ee ee ee EN _ Se a SB218 DELAY ARC 60 HZ 46 SB218 A B SB218 A MONO A 8 Table 11 DP224 Presets L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 59 of 158 OUT 4 Source V DOSC HI A V DOSC HI A V DOSC HI A V DOSC HI A V DOSC HI A V DOSC HI A dV DOSC HI B SB218 DELAY 4 A 58218 DELAY 4 DP226 V DOSC PRESETS OUT Source OUT2 Source OUT3 Sewce 4 Source OUTS Source 6 Source M DOSC3WiLO 10 5 V DOSCMID A _ ___ 5 V DOSCLO B V DOSCMID B _ V DOSCHI B 5 3wayseeo VDOSCLO 5 V DOSCHI A 5 V DOSCMID B _ V DOSCHI B E c nemo 0 109 0 S es e qu Sel V DOSC i LO 5 way A 14 V DOSC LO V DOSC MID A V DOSC HI A 5 way A S way A 1 B 16 5084 V DOSCLO A vDbOsCMD A vDoscH A FUL 58218 8 5 way A S way A 1 B 18 58218 vDbOSCMD A vDoscH A FUL
11. 94 Figure 72 Physically coupled subwoofer 95 Figure 73 Hybrid flown stacked subwoofer 96 Figure 74 Hybrid flown stacked subwoofer example essen eene eerte 96 Figure 75 Subwoofer arraying techniques lesse esee eene nnne nennen eene nnn nnns 98 Figure 76 Centre subwoofer line array a without and b with electronic delay processing 99 Figure 77 Electronic delay processing examples using a 4 or 6 channel 100 Figure 78 LCR Subwoofer arraying techniques 101 Figure 79 Large format subwoofer configuration with electronic delay processing 102 Figure 80 Geometric coordinates for the SUB ARC utility spreadsheet in 2004 103 Figure 81 Large format arena configuration 4 delay taps 4 0 201 1 6 00 eene 103 Figure 82 Large format open air festival 104 Figure 83 Large format stadium configuration 104 Figure 84 Stereo infill and distributed front fill options 105 Figure 85 Flown offstage fill system 5 106 Figure 86 Stacke
12. 64 29 lt D a S QT N nones O B p 9 e H gt e O es D p a Q pl 2 O 9 Q 9 o gj E Q i __ 3 e 5 T e g g m oa m Eu Master Rack 4 55 495 qo ge 45 de He g BEA BI gt Ek E VAS KREN 9 9 9 qn 5 X AUI Z 4 P a 9 C e 9 3 Ti pam q 9 G g E g P g e Esrar E aun b H3 a e RN S ee me B Qa Bm Ie Q D 5 B pa Q a Slave Rack a E a Figure 27 L ACOUSTICS Amplifier Rack Options a
13. DSP MEA 2 0 SER TO DSP INPUTS 4 972 SA G2 N 5 AA WI TAR a ex OC o oco o90 9 M WF WY WA CE RS232 w A WS RS485 OUT 5 LO B 4 SUB B 3 2 P 1 ee Figure 34 CO6 Control Output Panel L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 50 of 158 1 13 APPROVED DIGITAL SIGNAL PROCESSORS Digital signal processing units supported by L ACOUSTICS for V DOSC include DP224 XTA DP226 or DP6i fixed install version of the DP226 BSS FDS 366 Omnidrive Compact Plus BSS Soundweb and Lake Contour OEM factory presets for these DSP units are distributed via PCMCIA Card excluding XTA DP6i BSS Soundweb and Lake Contour OEM presets for these units are downloaded via computer and are available from L ACOUSTICS France L ACOUSTICS US L ACOUSTICS UK or your local distributor Preset libraries and upgrades can also be downloaded from www l acoustics com Since the XTA DP226 is a 2 input x 6 output unit the DP224 is 2 x 4 the Lake Contour is 2 x 6 and the BSS 366 is 3 x 6 exact internal wiring of your FOH drive rack and DSP output channel assignments will vary depending on the selected processor and the application Carefully consider your flexibility requirements before selecting the number and type of DSP units to specify For full details on the operational and technical aspects of these DSP units p
14. 129 6 2 Recommended Maintenance 5 1 6 129 6 3 Spare Parts S 130 6 4 Recommended Installation Tools cccccccccccssscorsscersscsssconsscesssccescosesconsscenscccescosccessceesconeees 131 T SPECIFICATIONS ernan 132 7 V DOSC ENCLOSURE SPECIFICATIONS SE Sc 132 72 58218 SUBWOOFER 5 134 1 3 RIGGING STRUCTURES 135 V DOSC BUMP 2 135 58218 BUMPSUB Rigging eee n eT vh 136 7 4 CO24 MD24 Line Assignment 1 11 137 7 5 CO24 Control Output Panel Line Assignments 1 1 0 eee eee eee eene tees nose 138 7 6 MD24 Multi Distro Panel Line 5 1 1 1 1 140 APPENDIX 1 Why Do Separated Sound Sources 1 5 142 APPENDIX 2 Further Explanations Regarding WST Criteria 1 6 142 APPENDIX 3 How Does V DOSC Behave
15. suB 2wH HI B HI A HI B 3 3 top js 4 and 1 2 VIOLET suB 2 2wLo LO B LO LO B 3 7 gnd 1 AMP 4 2 CHB LO SUB 3 Hi SUB B HI HI B 9 3 top 10 and 1 11 2 ORANGE Lo SUB 4 210 SUB LO LO B 12 3 2 AMP RACK WIRING DIAGRAM CHANNEL B CHANNEL A AMP 1 ChB White AMP 1 ChB Red Speakon AMP 1 Brown XLR AMP 1 ChA Blue Speakon Q AMP 2 ChB Orange XLR AMP 2 ChA XLR 2 ChB Yellow Speakon emm e 2 Green Speakon NEM dd m Q gt Figure 25 PADO2a amp rack wiring L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 42 of 158 1 8 V DOSC AMPLIFIER RACKS Figure 26 LLACOUSTICS Amplifier Rack RK124a loaded with 4 x LLACOUSTICS LA48a amplifiers The L ACOUSTICS amplifier rack RKI2U is 12 rack units high and can be loaded with up to 4 L ACOUSTICS LA48a amplifiers and the PADO4a amp rack panel Overall external dimensions are 77 cm high including casters x 61 cm wide x 58 cm deep 30 3 x 26 4 x 22 9 inches Clearance from the front rack rail to the f
16. 5 RIGHT IN 2 5 8 DIGITAL 2 SUB 8 2 LEFT RIGHT LINES Sub Low Mid High Fill Lo Fill Hi CONTROL RACK FOH CROSS LINK DOM 30 EERE EEE TEETER EEE EEE EEE EEE EEE EEE TEETER EEE EEE EEE HEHEHE EEE HEHEHE EEE ETHER Hee MULTI DISTRO PANEL AMP LINK EERE EE EEE BUMPER AMP RACK FULL RANGE FULL RANGE V LINK C 5 X ANGLE 10 X SPACER V CABLE 6 X V DOSC ELEMENT 18 FULL RANGE FULL RANGE LINK 3 unk fz 12 19 V CABLE V CABLE 0025 B F LINK 72 X 2 WAY FILL AMP 1 WAY dV DOSC AMP LINK 1 LINK 42 5 KI F CABLE EAL gt SP25 4 58218 SUB AMP 508 LINK 5 LINK 12 SUB CABLE gt SUB CABLE 7 IS z THUS gt STAGE HOUSE L STAGE L HOUSE R Figure 6 V DOSC System Block Diagram L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 20 158 V LINK DO 7 V CABLE DO 25 AMPLIFIER REMOTE CONTROL MONITOR BUMPER 5 X ANGLE 10 X SPACER 6 X V DOSC ELEMENT 71 X 2 WAY FILL dV DOSC 4xSB218 1 qV DOSCL dV DOSC 16 V DOSC ira 6 dV DOSC d 12 58218 a o ES o 12 L ACOUSTICS RKI24a 2
17. Standards conformity Mc V DOSC loudspeaker enclosures are designed to be suspended from the rigging structure BUMP2 only in accordance with published L ACOLISTICS instructions Up to 16 V DOSC can be suspended in a vertical column below the BUMP2 rigging structure when used as a suspension frame using 2 rigging points front rear Up to 6 V DOSC enclosures can be stacked when using the BUMP2 structure as a stacking platform Adjacent DOSC enclosures are securely attached to each other and to the BUIMP2 rigging structure using 2 stainless steel 5 pins DOAXE Two ANGLE STRAPS are attached to the side mounted aluminum track on each side of the V DOSC enclosure and are used to set the angle between adjacent enclosures ANGLE STRAPS are constructed of 2 double stud aircraft fittings that are attached with shackles to a steel bar and are normally not load bearing elements of the rigging system The design testing and quality control assurance procedures of the V DOSC loudspeaker enclosure were validated with the participation of the WELDING INSTITUTE an independent French inspection office Technical Reports 40630 and 40167 These reports are part of the development documentation for V DXOSC and are reserved for L ACOUSTICS internal use L ACOLISTICS has engineered the V DOSC laudspeaker enclosure using state of the art modeling and calculation software The rigging parts of the V DOSC enclosure have been d
18. The ideal situation is achieved when sound sources get so close to each other that they become equivalent to a flat radiating ribbon or continuous line source This solves the source separation problem at higher frequencies where the wavelength is smaller than the size of the drivers for example 2 cm at f 16 kHz since the chaotic multiple source wavefront is replaced by single well defined wavefront With further analysis it is shown in the first AES preprint that optimized coupling can be achieved in two ways the first way is to minimize the spacing of sound source acoustic centers to less than half the smallest wavelength corresponding to the upper frequency of their operating bandwidth the second way is to shape the radiated wavefront of the sound sources into a flat isophasic ribbon with no more than 20 discontinuity of the radiating area In the AES journal paper Wavefront Sculpture Technology these two WST Criteria were re derived based on an intuitive approach using Fresnel analysis and in addition it was shown that The deviation from a flat wavefront must be less than A 4 at the highest operating frequency this corresponds to less than 5 mm of curvature at 16 kHz the DOSC waveguide provides less than 4 mm of curvature at this frequency curved arrays enclosure tilt angles should vary in inverse proportion to the listener distance geometrically this is equivalent to shaping variable curvatu
19. female 19 pin CA COM connector at one end 6x male XLR connectors at the other used as a LINK cable breakout for patching and testing purposes DOMF LINK BREAKOUT Multipair cable adapter with Ix female 19 pin CA COM connector at one end 6x female connectors at the other used as a LINK cable breakout for patching and testing purposes Note Parts nomenclature is as follows DOM DOSC Modulation DOMP DOSC Modulation Prolongateur French for extender L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 29 of 158 L AcOUSTICS MD 24 MULTI DISTRO L ACOUSTICS CO 24 CONTROL OUTPUT z i Baer all Ru i e 1 A m J al 24 CONTROL OUTPUT MD24 MULTI DISTRO DOM30 CROSS LINK DOMM LINK BREAKOUT DOMP LINK EXTEND PCMCIA CARD Figure 15 Signal distribution and cabling L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 30 of 158 LOUDSPEAKER CABLING 36 37 38 39 40 41 42 43 44 45 46 47 48 DO 7 V CABLE V DOSC loudspeaker cable 8 conductor 4 mm conductor cross section 0 7 m 2 ft length equipped with male female CA COM connectors for parallel connection of V DOSC enclosures DO7 V CABLE V DOSC loudspeaker cable 8 conductor 4 mm conductor cross section 7 m 20 ft length equipped with male female CA COM connectors for connecting V DOSC enclosures to PADO2a or PADO4a DO25 V CABLE
20. ii gt 8 GREEN ef LEFT LEFT e BLACK RT 35 YELLOW ETET 2 33 BLACK SUB L 32 ORANGE L Su gt S gt gt gt gt 0 1 lt LEFT LEFT 2 FILL LEFT LEFT GREEN P 2 WAY FILL LEFT LEFT 29 GND N 2WAYFILLHF LEFT LEFT 28 RED U 2WAYFILLF LEFT LEFT YELLOW T 2WAYFILLF LEFT LEFT 20 S 2WAYFILLLF LEFT LEFT __ 5 RED C LEFT ORANGE B B LEFT 23 GND B A LEFT GREEN B F MD LEFT BUE E X 9 MD LEFT 19 B D LEFT P P S gt gt gt L 18 GREEN 17 BROWN H LEFT e 15 WHITE M SUB LEFT 1 8 1 188 K SUB LEFT sy Ee 11 BROWN 8 P 2WAYFLLHF X LEFT O 4 CND N 2WAYFILLHF LEFT 7 10 BLUE U 2WAYFILLLF LEFT 9 YELLOW B T 2WAYFILLLF LET _ 8 CND B S 2WAYFILLLF LEFT BLUE REMOTE IN F 4pin XLR 1 ___ XLR 2 XLR 3 XLR 4 1 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 141 of 158 APPENDIX 1 WHY DO SEPARATED SOUND SOURCES IN
21. 38 0 Emori 23 14 0 m T 2 3 81 m Boum V DOSC Eleven _ 1048 m Coni Wines SPL per ain dB shelving eq LOssmoeth Hi bright Peat Linvid SPL for 7 156 dB 30 Hz HPF V DOSC low section CUTEM 2 5 0 Eaton 21 0 0 m Section 2 30 0 m ____ om Lianer 4 2 CLEAR ALL FACTOR CALCULATOR me METRIC CONVERSION UTILITY 3Wi B HzHPF V DOSC low section 24 00 7 40 in _ MECHANICAL DATA V DOSC ONLY le di 80 crossover SB218 V DOSC DR Distance iri metres m 932 2055 Ibs ged Cystance n rmm 28 mm Fear Los 478 kg Ibs a isse sm INFRA 80 Hz crossover 58218 V DOSC V DOSC ARRAY 82 VERTICAL COVERAGE DATA _ 504 V DOSC law 30 200 Hz Offset Distance 5 0m Horna Coverage 2 Leg Gres am kg 1158 T 4 Dwucfury Conta at F1 247 Hz munt A XAUX cile e Hamnegata polarty Corte De actrate abow 2 888 Ange Giress 407 kg 897 v pasc low 30 200 Hz 459 Hz Wieschanic OK Maroney 58218 25 60 Hz dV SUB V DOSC low 80 200 Hz SWX 58218 25 00 dv SUB v DOSC low
22. 8288 S way A 1 B 19 SB218 A V DOSCLO A V DOSCMID A V DOSCHI A term oen cs EHE REESE LE mn E jh or tom mae a eS G 99 SSS SS V DOSC i dV LO 4 way 2 B V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO B dV DOSC HI B 4 way 2 B 4 way 2 B 4 way 2 B 4 way A 2 8 4 way 2 B ng Sa G vM ea m i eR es ee ee V DOSC i AUX dVLO 5 way A B 26 V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI A 5 way A B 5 way 5 way A 1 B 209 0 ES as ee c CEN aa a ee ee V DOSC i ARCS LO 4 way A 2 30 V DOSC LO A V DOSC MID A V DOSC HI A 4 way A 2 B 4 way A 2 B 4 way A 2 4 way A 2 B 4 way 2 BEER Ic MU a X a a a ee V DOSC i AUX ARCS LO 5 way A B 36 V DOSC LO A V DOSC MID A V DOSC HI A 5 way 5 way 5 A 1 B eee ee Rr eae ee a a Se a ee a haa UY IIS ke CR TR C Nc n a ag CES ee eer aa V DOSC dV SUB SB2
23. Combined area STEP 2 2 of discrete sources over the bandwidth HIFW H2 W of operation 2 80 of target area H W Figure 2 Wavefront Sculpture Technology Conditions and 2 Illustrated Additional conditions were published in the Audio Engineering Society journal paper Wavefront Sculpture Technology JAES Vol 51 No 10 October 2003 The first two WST conditions were derived based on an intuitive approach using Fresnel analysis and in addition it was shown that 3 Deviation from the ideal target wavefront flat or curved radiated by individual sources of the array must be less than a quarter wavelength at the highest operating frequency this corresponds to less than 5 mm of variation at 16 kHz 4 For curved arrays enclosure site angles should vary in inverse proportion to the listener distance geometrically this is equivalent to shaping variable curvature arrays to provide equal spacing of individual enclosure site angle impacts on the audience listening plane 5 Limits exist concerning the vertical height of each enclosure the minimum allowed listener distance and the angles that are allowed between enclosures The key to satisfying WST conditions at higher frequencies is a proprietary L ACOUSTICS waveguide that is used to load a conventional compression driver This DOSC waveguide was invented by Dr Christian Heil and is patented world wide see Appendix 4 DOSC stands for Diffuseur d Onde Sonore C
24. DIFFERENCE d V DOSC d SUB PATH DIFFERENCE PATH DIFFERENCE d v DOSC d SUB d SUB MEASUREMENT STAGE MICROPHONE 5821 8 58 21 8 TIME DELAY PATH DIFFERENCE meters 343 meters second Figure 70 Flown V DOSC and ground stacked subwoofer time alignment FLOOR L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 93 of 158 Selection of the time alignment reference location is always a compromise since the geometric path difference will vary with position Time aligning at a distance where the SPL from the ground stacked subwoofers equals the SPL from the V DOSC low section is recommended as an optimum compromise Horizontally the reference position should be on axis or in between the V DOSC and subwoofer arrays Time aligning in the middle is not recommended in order to help reduce centre build up and one side of the system should be time aligned at a time FOH L as shown in Fig 71 TIME ALIGNMENT REFERENCE AXIS TIME ALIGNMENT REFERENCE DISTANCE PL 50210 SPL 005 LOW Figure 71 Recommended time alignment reference location for flown V DOSC ground stacked L R subwoofers For ground stacked LCR subwoofer arrays it is recommended that the L subwoofer array is delayed with respect C array with the microphone on axis to the L array Following this the flown V DOSC array should be time aligned with respect to the L array using the techniques outlined in Figure 71 When subwoofers
25. LA48a plus PADO4a b 4x LA48a plus 2x PADO2a c Master Rack with DSP CO6 Control Output 2x LA48a PADO2a d Slave Rack with 2x LA48a PADO2a L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 44 of 158 1 9 COMB CONNECTORS COMB connectors are used in conjunction with L ACOUSTICS signal distribution panels CO6 24 MD24 to route desired signal lines from the 19 CA COM input connectors on PADO2a or PADO4a amplifier rack panels to the appropriate amplifier inputs Amplifier racks can be conveniently reconfigured without rewiring internally simply by changing the COMB connector COMB connectors for use with V DOSC 4 way 2 5 way format presets DSUB SUB signal line for SB218 D3WAY 3 WAY signal lines 2 3 4 for V DOSC low mid high respectively D2WAY 2 WAY signal lines 5 6 for dV DOSC mid high respectively Additional COMB connectors are available for use with 2 way or 3 way stereo format presets are D2WA 2W A signal lines 2 3 for 2 way low high D2WB 2W B signal lines 5 6 for 2 way low high D2WSTEREO 2W STEREO signal lines 2 3 and 5 6 for stereo2 way low high D3WA 3W A signal lines 1 2 3 for sub 2 way low 2 way high D3WB 3W B signal lines 4 5 6 for sub 2 way low 2 way high DSUBA SUB A signal line for sub drive DSUBB SUB B signal line 4 for sub drive DSUBTK is a set of 6 COMB connectors for implementing electronic arc delay processing of
26. T J 2WAYFLLLF RIGHT _ 20 GND 2WAYFILLLF RIGHT RIGHT RIGHT e D A RIGHT RIGHT _ 21 GREEN D F MD RIGHTI RIGHT _ 20 YELLOW D RIGHT RIGHT _ 19 GND D D MD RIGHTRIGHT _ 18 GREEN D J RIGHT RIGHT _ 17 ORANGE D H p IE _ RIGHT RIGHT 35 ware b 8 14 YELLOW D L SUB RIGHT RIGHT _ K DIO 12 WHITE 2 WAY FILL HF RIGHT RIGHT ORANGE 56 EX MR 2 WAY FILL HF RIGHT RIGHT GND 2 WAY FILL HF RIGHT RIGHT I oc BLUE 2 FILLLF RIGHT RIGHT 9 BROWN D T 2WAYFILLF RIGHT RIGHT 8 GND S 2WAYFILLLF RIGHT RIGHT _ ____ OUT XLR 1 ___ ame ___ OUT XLR 2 3 ORANGE REMOTE M 4pin _ Bours uem ___ oo 2 YELLOW REMOTE M 4pin Booms ___ __ 1 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 140 of 158 Table 195 MD24 W6 Socket Assignments W6 W6 CACOM CACOM PROCESSOR LOUDSPEAKE Socket COLOR CHANNEL PIN CHANNEL R CODE ARRAY 42 BACK HF X LEFTLEFT 41 RD B J s Jp _ SHE MD LEFTLEFT
27. In 2 WAY mode dV DOSC ARCS enclosures can be connected via the lower 2 x Speakon NL4 connectors using SP7 or SP25 cables or alternatively via the 8 pin CA COM connector using DO2W cables directly or DO7 DO25 cables plus DOFILL adapter L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 40 of 158 Table 3 PADO4a COMB Wiring Chart PAD 04a COMB PANEL AMPLIFIER WIRING CHANNEL ASSIGNMENTS COMB WIRING INPUT REASSIGH gt LINES 1 12 CHANNEL A DSP OUTPUT CHAHHEL ASSIGNMENTS gt PADO4a LINES 14 31 4 2 PRESET COHFIGURATIOH STEREO COHFIG 2W STEREO COHFIG LIHES 1 12 gt AMP CH 5 1 CONFIG 4 2 CONFIG 344 STEREO 2w STEREO COMD24 LINE SIGNAL SUBD 37 SUB 3v ST AA STEREO Zw ST 2 ST SUBD 37 AMP CH 17 26 17 17 24 18 18 25 18 23 20 20 24 21 21 22 7 8 9 EXEXEXES IE Sc el IER 26 1 27 2 LA48a 1 28 3 29 4 30 5 LA48a 2 22 31 6 26 1 26 7 27 1 2 8 28 1 8 29 20 29 10 30 21 30 31 22 31 CHANNEL 3W STEREO COHFIG 2W STEREO CONFIG LIHES 1 12 gt CH 17 26 17 17 26 1 18 27 18 18 27 LA48a 1 19 28 19 19 28 CHB 20 29 20 29 21 30 21 30 LA48a 2 22 31 22 31 CHB 23 14 26 24 15 27 8 LA48a 3 25 16 28 CHB 14 9 20 29 10 15 0 21 30 11 LA48a 4 1 31 22 31 12 CHB Table 4 PADO4a Internal Amp Rack Wiring Chart AMP RACK INTERNAL WIRIN
28. It is recommended that arc radii remain shallow so that the difference between T3 T4 remains less than 15 msec Steeper arc radii will decorrelate LL versus and RR versus R V DOSC arrays to the extent that the LL array will be perceived as an echo with respect to the L array Apart from smoother low frequency coverage in the horizontal plane electronic delay processing of the main arrays has the added benefit of improved stereo perception since psychoacoustically this helps to localize the audience s attention towards the stage and not the nearest loudspeaker array LE L R R R BE Fe ES Figure 79 Large format subwoofer configuration with electronic delay processing L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 102 of 158 Enter physical location x coordinates 4 Enter arc radius y coordinate yl y2 backline A T2 TI n n 2 Calculate alignment delay x coordinate
29. st 224 SN VX NN LOS p k sb L 4 i N NEA WA H d iz 47 1 4 Figure 91 Stacked V DOSC offstage fill system Radiohead Oxford 2003 sound design Bernard L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 111 of 158 4 2 FLOWN SYSTEM Rigging a V DOSC array is fast and easy with significantly reduced handling time compared to conventional systems Please refer to the photo sequence in Figure 94 with respect to the following description of flying procedures Preliminary Preparations All installation data for rigging the array i e bottom enclosure elevation inter enclosure angles top and bottom enclosure site angles has been calculated using ARRAY 2004 or SOUNDVISION and mechanical data checked to ensure safe rigging conditions see Figs 92 94 Two independent rigging points are available with a spacing of 1 05 meters 43 4 and the desired onstage rotation angle for the array Alternatively three points can be used along with a swivel shackle for connecting the delta plate to the rear BUMP2 point this allows for pan adjustment of the flown array see Fig 19 Rigging points should be equipped with 0 5T chain motors for 4 enclosure array 0T motors fora 5 10 array 2 0T motors for to 16 array Access is available beneath the rigging points i e a
30. 30 200 Hz dv DOSC DOWNFILL 4 av cosc 2 00 COMMENTS 2 CUTVIEW SHEET HORIZONTAL ISOCONTOUR ARRAYS V2 Isocontour at distance m Console output signal dBu X location m Y location m Azimuth angle deg 5 50 0 Headroom 88 9 9 8 8 Cont A weighted SPL dBA AUDIENCE CONTOUR meters CONTOUR 1 CONTOUR 2 Scaling Clear All 60 50 40 30 20 HORIZONTAL ISOCONTOUR SHEET Figure 50 ARRAY 2004 spreadsheet calculation example L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 75 of 158 2 4 V DOSC COVERAGE MODELING USING SOUNDVISION L ACOUSTICS SOUNDVISION is a proprietary 3D software program dedicated to the modeling of the entire L ACOUSTICS product line including V DOSC dV DOSC KUDO ARCS XT and MTD enclosures Designed with a convenient intuitive graphical user interface SOUNDVISION allows for the calculation of sound pressure level SPL and coverage mapping for complex sound system or venue configurations Room geometry and loudspeaker locations are defined in 3D and simplified operating modes allow the user to work in 2D to rapidly enter data According to user preference either horizontal plan or vertical cut views can be selected to enter room coordinates or to define loudspeaker placement aiming SPL plus coverage mapping are then based on direct sound calculations o
31. 4 55 55 5 65 Variable Curvature V DOSC Array cccsiiccsccccsecccesscctessncsssccecscacescscesnaccessncsesccentsccsasstetessecesensecsseces 66 2 3 V DOSC COVERAGE MODELING USING ARRAY 2004 4 2 2 66 CUT VIEW SHIBE TS 67 V ARRAY V ARRAY 2 Input reete eren eo th eee Seu ee eh 67 Optimization 69 cuss 70 dV ARRAY 2 Input 1 0 1 eus 72 599 2 a e oae 72 5 fe 74 74 Optimization Procedufte niei 74 Output D ta M 74 2 4 V DOSC COVERAGE MODELING USING SOUNDVISION 1 0 6 eee 76 SOUNDVISION EXAMPLES 55555 ues 80 SOUNDVISION STADIUM 11 1 80 SOUNDVISION ARENA EXAMBPLE 5595 e vie see eo ana e eue e caa Sev sese paese 82 3 SOUND DESIG
32. 58218 58218 58218 58218 VDVSSBiL 5828 VDOSCLO 5 58218 8 MDVsSBiH 5 29 5084 vposcMD 58218 8 VDVSSBXL sig 58218 5 __ 58218 8 VDVSSBXH 59g 9 5 2 8 __ __ V DOSCLO A V DOSC MID A 5 _ ____58218 8 NIC 0 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 62 of 158 2 V DOSC COVERAGE MODELING V DOSC can be modelled using L ACOUSTICS proprietary SOUNDVISION or ARRAY2004 software Alternatively custom DLLs for V DOSC and dV DOSC modeling are available for CATT Acoustics or EASE room acoustics modeling sofware 2 1 COVERAGE IN THE HORIZONTAL PLANE V DOSC has a coverage angle of 90 in the horizontal plane from 630 to 12 5 Hz with 6 dB points at 45 off axis Horizontal coverage is independent of both the number of arrayed V DOSC enclosures and the vertical configuration of the array Due to the coplanar symmetric arrangement of components the horizontal coverage pattern is symmetrical with respect to the 0 axis Note Although coverage angles are by definition determined by the 6 dB points for most sound design applications the 3 d
33. e Some countries require higher safety factors and specific rigging approvals It is the responsibility of the user to ensure that any overhead suspension installation of L ACOUSTICS systems is made in accordance with all applicable local or state regulations e L ACOUSTICS is not responsible for any rigging equipment or accessories that are not manufactured by L ACOUSTICS 4 1 STACKED SYSTEM For stability reasons the maximum number of V DOSC enclosures that can be stacked is 6 total weight including the bumper is 709 kg or 1563 Ibs The V DOSC BUMP2 bumper is used as stacking platform and four corner screwjacks allow for tilt adjustment of the stacked system Prior to stacking the strength of the supporting floor should be carefully examined to determine if the load can be supported if necessary sheets of plywood or steel plates can be placed under individual screwjack feet to help distribute the load Once the location for the stacked array has been determined the BUMP2 is placed in the desired location and oriented upside down so that the two rotating legs on the BUMP2 are free to swing upwards To install the corner screwjacks lower the height adjustment blocks to the minimum position Mount the screwjacks the corners of BUMP2 by sliding the blocks into the locating slots on BUMP2 and then lower the screwjacks Note For greater stability when tilting the stacked system downwards the front pair of screwjacks can be omitted
34. ratchet strap handle is accessible While referring to the remote inclinometer adjust the front rear motors to give the correct Site angle Allow the array to settle then measure the site angle of the bottom enclosure Adjust the tension of the ratchet strap until the site angle of the bottom enclosure agrees with the value determined in ARRAY 2004 or SOUNDVISION At this point the vertical coverage of the array is correct Next raise the array to the calculated bumper elevation or bottom enclosure elevation Since front and rear chain motors can run at different speeds once you are at trim you must reset the focus angle of the array using either the remote inclinometer or by referring to a laser mounted on the top enclosure Repeat this process to ensure that the vertical coverage and focus of Left and Right arrays are exactly matched Trim and Site Angle Adjustments After the ratchet straps have been tensioned there are only two adjustments left trim height of the array and the site angle of the top enclosure which is performed by the relative action of the front and rear chain motors Due to different geometric coordinates in ARRAY2004 and SOUNDVISION the trim and site angle adjustment procedures are different ARRAY2004 installation data see Figs 48 and 94 The rear motor is used to set the elevation of the array and the front motor controls the site angle A tape measure should be attached at the upper rear corner of the top V DO
35. screwed and rabbeted in order to remain free of vibration at extreme sound pressure levels Dimensions are 550 mm 21 7 in high 1300 mm 51 2 in wide and 700 mm 27 6 in deep and enclosure weight is 115 kg 233 7 lbs The finish is brown gray RAL8019 structured polyurethane paint and the front of the enclosure is protected by a black powder coated 1 5 mm thick steel grill grille covered with 10 mm 0 4 in thick acoustically transparent open cell foam The SB218 has two recessed flytrack sections mounted on both sides for rigging purposes An accessory flying bar is available that allows for rigging of arrays up to 8 enclosures deep with greater than 5 safety factor Six recessed handles are located on the sides of the enclosure and a front mounted dolly board attaches to the enclosure using two locking pins and two front baffle mounted dolly locator studs L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 36 of 158 1 5 58218 RIGGING SYSTEM The 58218 BUMPSUB rigging system consists of one steel bar four 22 mm shackles and two chains incorporating Aeroquip double stud fittings The Aeroquip fittings are connected to the flytrack sections located on each side of the 58218 two per loudspeaker on each side 4 total per 58218 The BUMPSUB flying bar is rated for up to 8 subwoofer enclosures at 5 1 safety factor Note It is recommended to preattach shackles and fittings to the chains prior to flying Lay the chain out flat and remo
36. standard LR configurations For more details the interested reader is referred to Mixing Left Centre Right Managing Shed Sound the evolution of PA Methodology Solutions including LCR by Robert Scovill Live Sound International Nov Dec 2002 When using the LCR configuration for live music applications three V DOSC arrays can be installed with the C array at O degrees and the L R arrays panned offstage up to 20 degrees for speech reinforcement L R arrays can be panned offstage up to 70 degrees to optimize coverage and intelligibility For theatrical sound reinforcement the 120 degree coverage of dV DOSC is well suited to centre cluster applications since there is a good match between C system coverage and overall L R coverage for the typical 12 15 metre L R array separation that occurs in theatres Note As Scovill points out mixing console choice is a key element for making the LCR configuration work i e the console must be capable of generating an LCR mix suitable for live music sound reinforcement Console requirements for theatrical sound reinforcement are different since the centre cluster is typically used for speech reinforcement and the L R arrays for music NA N 75 20 LCR System 3 x V DOSC arrays for outdoor LCR System C dV DOSC LR V DOSC arrays for amphitheature shed sound reinforcement after Scovill theatrical sound reinforcem
37. subwoofer arrays or for powering passive enclosures SUB TI signal line SUB T2 signal line 2 SUB T3 signal line 3 SUB T4 signal line 4 SUB T5 signal line 5 SUB T6 signal line 6 For complete details regarding CA COM line assignments PADO2a and PADO4a wiring plus COMB connector wiring please refer to Tables 3 and 5 in the preceding section DSP output channel assignments for 4 2 and 5 format presets CO6 CO24 patching and 3 WAY SUB and 2 WAY COMB connector channel selection are summarized as follows Table 7 V DOSC preset DSP output channel assignment and COMB connector summary DSP OUTPUT 4 2 FORMAT 6 CO24 DSP OUTPUT 5 1 FORMAT CO6 CO24 ue ape ca pmo pos poe reser SUB A SUB A SB218 LO A V DOSC LO 2 LO A V DOSC LO MID A V DOSC MID MID A V DOSC MID HI A V DOSC HI HI A V DOSC HI 2W LO B dV DOSC LO FULL A 2W HI B dV DOSC HI SUB B AUX SUB DRIVE 2 WAY FILL AUX SUB DRIVE DSP OUTPUT 5 1 FORMAT 6 C024 DSP OUTPUT 5 1 FoRMAT coe co24 cen pue cem pen e Em pun LO A V DOSC LO SUB A MID A V DOSC MID LO A V DOSC LO HI A V DOSC HI MID A V DOSC MID 2W LO A dV DOSC LO HI A V DOSC HI 2W HI A dV DOSC HI FULL A SUB B SB218 SUB B SB218 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 45 of 158 Operating modes amplifier rack channel assignments and cabling plus loudspeaker enclosure combinations
38. 00 DOSZ 0 10 4 23 2 516 5 56 12 v DOSC 0 11 12 5 5 11 Mechanical Parameters motors 2 Bumper Bumper YOOSC Rear motor position 0 Max size chuse gA Y 22 5 5 0 7 1 3 Figure 93 SOUNDVISION installation report data V DOSC ARRAY 1 WAVEFRONT SCULPTURE TECHHOLOGY PREDICTION X Axis Scale Adjest x 10 3 83 4 4 3 2 1 10 3 8 7 6 5 4 3 2 10 123 4 5 6 10 11 12 13 14 15 16 17 18 20 21 22 23 24 25 26 27 26 23 30 31 32 33 34 35 36 37 56 33 40 41 42 43 44 45 46 47 45 43 50 AUDIENCE GEOMETRY 2 008 site 59 A D DISTANCE ELEVATION Rangefinder Heigh 000 DOWNFILL UPFILL dv CIOSC DOWNFILL 1 4 T 4 4 5 n 32 40 Autofocus Adjust 000 ume a 5 woscun n Up bd Figure 94 ARRAY 2004 installation data L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 113 of 158 The first step is to line up the enclosures at the rigging location while they are still face down on their dollies As a reference for cabinet orientation enclosure stacking runners will be oriented upwards and rear jack plate V DOSC logos will be upside down once the array is flown see Fig 95 a Enclosures are mechanically connected together using the rotating legs and U pins Use the locking safety pins to secure all U pins in place see
39. 11 16 enclosure arrays a bridled hang from the front and rear corner rigging points should be performed using two steel slings four shackles and one pear ring front and rear Always refer to the MECHANICAL DATA in ARRAY 2004 or SOUNDVISION to ensure that safe rigging conditions apply before installation Ensure that the immediate area is clear of people and obstacles whenever raising or lowering the array Announce in a loud voice whenever the array is being moved to get people s attention Always look up while moving the array to be sure that movement remains unimpeded and to check cable tension Once flown to trim and correctly angled remove the motor control cables so that the array cannot be tampered with by unauthorized people Always cover motors with plastic in outdoor installations where motors may be exposed to rain Do not overtighten ratchet straps especially if the array is tilted upwards 5 V DOSC SYSTEM OPERATION WARNING The V DOSC system is capable of producing high sound pressure levels Hearing loss or damage can occur with prolonged exposure to high SPLs Please operate your system responsibly at all times An SPL meter on the mix console is highly recommended as a reference Prior to describing system operation and tuning procedures subjective criteria and system setup objectives are first considered 5 1 SYSTEM TONAL BALANCE V DOSC and dV DOSC presets have been specifically engineered to provide an excelle
40. 20 0 100 0 i 1000 0 log Frequency Hz Figure 41 5W Infra preset time alignment procedure 5W X PRESET The 5W X preset features identical operating bandwidths for the V DOSC low section and dV SUBs 30 200 Hz while ground stacked SB218s are run from 25 80 Hz with negative polarity to account for the phase shift due to the overlap in operating bandwidths Given the optimized V DOSC LF shelving equalization plus the additional contribution of flown dV SUBs the sub low output of the flown system is maximized The 5W X preset is intended for configurations where SB218s are ground stacked and dV SUBs are flown beside V DOSC in a closely coupled configuration For the 5W X preset AUX SUB drive can be implemented using the SB218 DELAY ARC 80 Hz or SB218 LCR 80 Hz presets subs with negative polarity 5W X Align SB2 l 8 8 dip I peak dip2 with dV SUB V DOSC low section 582 8 polarity Transfer Function Rag di yer A ME core RES X SMa 20 0 100 0 1000 0 20 0 an s n log Frequency Hz msec Figure 42 5W X preset time alignment procedure L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 57 of 158 GENERAL GUIDELINES REGARDING SYSTEM PROTECTION As supplied by L ACOUSTICS limiter thresholds for all V DOSC OEM factory presets are initially set at 9 8 9 and 9 dBu for sub low mid and high sections respectively These limiter thresholds are matc
41. 2004 Geometric Data for 7 Figure 49 ARRAY 2004 Geometric Data for 5 4244 02222 1 000 73 Figure 50 ARRAY 2004 spreadsheet calculation example 75 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 8 of 158 Figure 51 SOUNDVISION Geometric Data for 5 22 000222000000 44 0 77 Figure 52 Plan view SPL mappings at octave band frequencies for 12 V DOSC 78 Figure 53 Impact coverage and SPL mappings for 12 79 Figure 54a Stadium example rear perspective view of full system impact coverage 80 Figure 54b Stadium example plan view of full system impact coverage 80 Figure 55 Stadium example rear perspective view of 1 10 kHz SPL 8l Figure 56 Arena example rigging 2 2 82 Figure 57 Arena example plan view of full system impact 82 Figure 58 Arena example rear perspective view of full system impact coverage 83 Figure 59a Arena example rear perspective view of full sy
42. 3 5 4 LARGE FORMAT SUBWOOFER ARRAY CONFIGURATIONS Electronic delay processing see Section 3 5 2 is also useful for large format V DOSC systems consisting of LL L R and RR arrays with associated subwoofer arrays flown or stacked in conjunction with a central horizontal line array see Figure 79 The optimum arc radius is typically equal to half the length of the central line array Delay taps are calculated geometrically based on this arc radius and the physical distance of a given subwoofer group off the center line reference y axis An EXCEL spreadsheet tool to help perform delay calculations is available in ARRAY2004 SUB ARC The LL and RR subwoofer line arrays are then time aligned with respect to the central horizontal line by taking measurements on their respective main axes In practice the center subwoofer array acts as the time reference and the length of the line array determines the arc radius Predelay can be applied to compensate for the physical placement of the centre line array and time align the system with the instrument backline kick drum monitor sidefills or monitor front line as desired This predelay is also applied to the relative arc delays 2 T3 and 4 that are calculated based on their physical XY coordinates Once electronic delay processing has been applied to all subwoofer arrays individual V DOSC arrays LL L R RR are delayed to maintain proper time alignment relative to their respective subwoofer arrays
43. 3 B 3 A 3 B 3 A 3 B 6 way A 6 way A 2 A 2 B 2 C 2 A 2 B 2 C 3W i LO 3WX LO V 3WXHI ViLO V 4W LO 4W VXLO VidVLO VidVHI V 4W dV LO V 4W dV HI V X dV LO X dV HI V XAUX dV L V XAUX dV H Vi ARC L V i ARC H 4W ARC L V 4W ARC H X ARC L V X ARC H XAUX AL V XAUX AH VDVSSBiL VDVSSBiH VDVSSBXL V DVS SBXH DV 2W 80 LO DV 2W 80 HI DV 2W 1001 DV 2W 100 H DV 3W 80 L DV 3W 80H DV 1201 DV 3W 20 DV 3W 1181 DV II8 H DV 1181 DV 3X 118 H DV 3W 2181 DV 3W 218H DV 3X 2181 DV 3X 218H AARCS 2W LO ARCS 2W HI 118 LO 118 218 LO 218 3W DVS LO 3W DVS 18 DEL 60 18 DEL 80 18 LCR 60 18 LCR 80 V DOSC LO A V DOSC LO A V DOSC LO A V DOSC LO A SB218 A 58218 A 58218 A SB218 A SB218 A SB218 A SB218 A SB218 A 58218 58218 58218 58218 58218 58218 58218 58218 58218 58218 58218 58218 58218 58218 58218 58218 58218 58218 FULL FULL FULL A FULL A dV SUB A dV SUB A dV SUB A dV SUB 58 18 A 58 118 A 58 18 A 58118 A 58218 58218 58218 58218 FULL FULL 58118 A 58118 58218 58218 dV SUB dV SUB
44. 4 The MTD XT SPACING sheet can be used to help calculate optimum spacing for a given throw distance for distributed sound reinforcement using MTD or XT coaxial loudspeakers The ROOM DIM sheet can be used to help calculate XZ cutview parameters based on room measurements Room dimension calculation utilities are also available in the V ARRAY2 dV ARRAY and dV ARRAY2 sheets In general all input data should be entered into the cells in black Results are displayed in red Note In order to run ARRAY Macro Security should be set at medium in Excel i e from the main menu bar select Tools Macro Security Security Level Medium Note A complete description of ARRAY2004 is beyond the scope of this manual For further information participation in a V DOSC Training Seminar is recommended L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 66 of 158 CUTVIEW SHEETS Four cutview sheets are available V ARRAY2 dV ARRAY2 Cutview sheets V ARRAY V ARRAY2 are used to simulate V DOSC arrays including dV DOSC downfill or upfill enclosures while dV ARRAY and dV ARRAY2 are used for simulating dV DOSC V ARRAY V ARRAY2 Input Data In AUDIENCE GEOMETRY cells the designer enters the distances and elevations that define the audience area according to a section view along the main zero degree axis of the system Cutview The origin of the x axis is referenced to the
45. 4 etc until you have checked all amp channels and all bands for each array If you encounter a polarity problem use a polarity checker to isolate the problem 4 Verify coverage by running low level pink noise through the system excluding subwoofers and walking the room Check the coverage down front and at the back of the venue Perform any required trim and angle adjustments if necessary 5 Using your measurement system at the mix position compare Left versus Right polarity and frequency response channel by channel as a final system check All responses should be identical within dB except for the high band where larger deviations are acceptable 2 to 3 dB Beware of wind effects which can affect HF measurement stability and repeatability 6 Typically the subwoofers act as an overall time reference for the complete system so the next step is to time align the subwoofers to the main arrays If a time domain measurement system WinMLS MLSSA TDS is not available use a laser rangefinder to measure the geometric difference between the main array and the subs at your reference point of choice Adjust the subwoofer delay by adding the geometrically determined delay to the pre aligned subwoofer delay that is included in the OEM preset as a starting point Place a microphone on the floor at your reference point of choice on axis or equidistant between the left V DOSC and left subwoofer arrays alternatively time alignment measure
46. 98 SB218 Subwoofer Line Drawing Page 134 of 158 7 3 RIGGING STRUCTURES V DOSC BUMP2 Bumper Dimension WxHxD 1262 mm x 140 mm x 1100 mm 49 5 8 x 5 4 8 x 43 3 8 Weight 61 5 kg 135 6 Ibs aL Figure 99 V DOSC Flying Bumper Line Drawing L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 135 of 158 Table 16 Weights for flown V DOSC system Number of V DOSC Cabinets SB218 BUMPSUB Rigging Bar Dimension WxHxD 1420 mm x 140 mm x 40 mm 55 7 8 x 5 4 8 x 1 5 8 Weight 12 kg 26 5 Ibs 1420 40 i 140 Scale 1 20 1 5 Figure 100 58218 Flying Bar Line Drawing L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 136 of 158 7 4 24 MD24 Line Assignment Summary Table 17 Whirlwind W6 MASS Connector Input Output Line Assignments W6 OUTPUT W6 INPUT 24 24 WHIRLWIND W6 PINS W6 SOCKETS WHIRLWIND W6 PINS W6 SOCKETS PAIR XLR CACOM XLR CACOM PAIR CACOM CACOM NUMBER ASSIGNMENT ASSIGNMENT NUMBER ASSIGNMENT ASSIGNMENT 4 A ABC A ABC C4 C ABC A3 A DEF A DEF C3 C DEF A2 A GHJ A C2 C A1 A KLM A KLM C1 C KLM A NPR A NPR C6 C NPR 5 A STU A STU C5 C STU B4 B ABC B ABC D4 D ABC B3 B DEF B DEF D3 D DEF B2 GHJ GHJ 02 D 1 B KLM B KLM D1 D KLM B6 B NPR B NPR D6 D NPR B5 B STU B
47. AMP 4 ChB Orange XLR AMP 4 ChB Yellow Speakon AMP 3 ChA White XLR AMP 3 ChA Red Speakon AMP 4 ChA Orange XLR ee AMP 4 Yellow Speakon Figure 24 PADO4a amp rack wiring L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 41 of 158 Table 5 PADO2a COMB Wiring Chart 02 COMB PANEL AMPLIFIER WIRING CHANNEL ASSIGNMENTS COMB WIRING INPUT REASSIGH gt LINES 1 12 DSP OUTPUT CHAHHEL ASSIGHMEHTS gt PADO2a LINES 14 31 4 2 PRESET CONFIGURATION 3W STEREO COHFIG 2W STEREO COHFIG LIHES 1 12 gt AMP CH 5 1 CONFIG 4 2 CONFIG 3 STEREO STEREO SUB D 37 AMP 1 top AMP 2 bottom AMP 4 CHB top AMP 2 CHB bottom SUB D 37 1 2 3 4 5 6 7 8 3 10 DIESES Table 6 PADO2a Internal Amp Rack Wiring Chart AMP RACK INTERNAL WIRING SUB D gt AMPS gt CACOMS AMPLIFIER CHANNEL ASSIGNMENT SUB D 37 SPEAKON SWAY PANAY IN ST AA STEREO AN ST 2ST 1 gnd 1 AMP 1 2 2 BROWN 1
48. B V DOSC MID A V DOSC HI A V DOSC LO B V DOSC MID B V DOSC HI B V DOSC LO A V DOSC MID A V DOSC HI A FULL A 58218 V DOSC LO A V DOSC MID A V DOSC HI A FULL A 58218 B V DOSC LO A V DOSC MID A V DOSC HI A FULL A SB218 B V DOSC LO A V DOSC MID A V DOSC HI A FULL A 58218 V DOSC LO A V DOSC MID A V DOSC A FULL A 58218 V DOSC LO A V DOSC MID A V DOSC A FULL A 58218 V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI A V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSCHI A V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI A V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI A V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI A V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI A V DOSC LO A V DOSC MID A V DOSCHI A dV DOSC LO A dV DOSC HI A V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI V DOSC LO A V DOSC MID A V DOSC HI A ARCS LO B ARCS HI B V DOSC LO A V DOSC MID A V DOSC HI A ARCS LO B ARCS HI B V DOSC LO A V DOSC MID A V DOSCHI A ARCS LO B ARCS HI B V DOSC LO A V DOSC MID A V DOSCHI A ARCS LO B ARCS HI B V DOSC LO A V DOSC MID A V DOSC HI A ARCS LO B ARCS V DOSC LO A V DOSC MID A V DOSC A ARCS LO B ARCS HI B V DOSC LO A V DOSC MID A
49. C and L arrays is identical ii time align V DOSC FOH L with respect to L with the measurement microphone located between FOH L and ground stacked L subwoofers at a distance where the SPL from the low section of the flown system equals the SPL from the ground stacked subwoofers iii duplicate the time alignment settings for R subwoofers and FOH iv if applicable time align LL and RR to L and respectively using a measurement location in a representative location where the coverage of the main and off stage fill systems overlap Figures 78 c f show various hybrid flown LR ground stacked C configurations Figure 78 c shows a central ground stacked C position d shows a L R ground stacked C position which also functions as part of a stereo infill system e shows a central subwoofer line array with electronic delay processing f shows a distributed ground stack subwoofer configuration which can also be used with electronic delay processing For all of these configurations a time alignment procedure similar to what is recommended for figure 78 c should be employed L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 100 of 158 k N d sl ee s T EN e Flown L R centre line array with electronic delay processing f Flown L R distributed ground stacked subwoofers Figure 78 LCR Subwoofer arraying techniques L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 101 of 158
50. DO7 or 25 DO3WFILL 3 dV DOSC ARCS XT 3 dV DOSC ARCS XT 4 SUBS 4 SUBS 2 SUBS 2 SUBS Figure 30 LLACOUSTICS RK122a amplifier rack channel assignments and cabling for 2 way and 3 way stereo presets L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 47 of 158 Operating modes amplifier rack channel assignments and cabling plus loudspeaker enclosure combinations for the L ACOUSTICS 24a amplifier rack PADO4a plus 4 x LA48a are as follows 2 WAY STEREO PRESETS 2W A 2W B DO10P DO2W DO10P DO2W DO10P DO2W DO10P DO2W or or or or DO7 or 25 DOFILL DO7 or 25 DOFILL DO7 or 25 DOFILL DO7 or 25 DOFILL or or or or DO2W SP7 22DO2W SP7 25 DO2W CC4FB SP7 25 DO2W SP7 25 T 5 T l 3 3 dV DOSC ARCS XT 3 3 dV DOSC ARCS XT 3 3 dV DOSC ARCS XT 3 3 dV DOSC ARCS XT 3 WAY STEREO PRESETS SUB A DO7 or 25 DO3WFILL DO7 or 25 DO3WFILL DOSUB or or DO3W CC4FB SP7 2 DO3W SP7 25 1 i 3dV DOSC ARCS XT 3dV DOSC ARCS XT 2 SUB 2 SUB Figure 31 LLACOUSTICS RK124a amplifier rack channel assignments and cabling for 2 way and 3 way stereo presets L ACOUSTICS V DOSC Manual Version 4 6 29 2005 w DO10P RK124 SUB B SUB A SUB B SUB A SUB B SUB A SUB B Page 48 of 158 1 10 CO24 CONTROL OUTPUT PANEL L ACOUSTICS 24 CONTROL OUTPUT LEFT LEFT R
51. L RISHERISHE _ 17 ORANGE D2 RIGHT RIGHT 15 WHITE M SUB RIGHT RIGHT rst RGHERIHI K RIGHT RIGHT LCE RIGHE RIGHT 11 ORANGE D6 2 D P WAY FILL HF __4 GND 16 1 D 2 RIGHT RIGHT 10 BLUE 05 3 D U 9 22WAYFLLLF RIGHT RIGHT IN 1 __ IN 2 3 _ IN 4 pd eee i L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 139 of 158 7 6 MD24 Multi Distro Panel Line Assignments Table 19a MD24 W6 Pin Assignments W6 PIN W6 CACOM CACOM PROCESSOR LOUDSPEAKER COLOR CHANNEL PIN CHANNEL ARRAY CODE BLACK RIGHT WHITE B HF RIGHT 40 CAH RIGHT BLACK F MD RIGHT BLUE E MD RIGHT 37 GND D RIGHT BLACK J3 RIGHT BROWN LF RIGHT G 33 RED M 5908 32 WHITE L SB RIGHT 22 GND SUB 2 WAY FILL HF 30 BLUE P J 2WAYFLLHF RIGHT 290 C _ 2WAYFILLHF _ 28 RED U 4 2WAYFILLLF RIGHT _ 27 BROWN
52. LO B dV DOSC HI B ARCS LOW A ARCS HI A FULL B ARCS LOW B ARCS HI B ARCS LOW A ARCS HI A FULL B ARCS LOW B ARCS HI B ARCS LOW A ARCS HI A 58118 B ARCS LOW B ARCS HI B ARCS LOW A ARCS HI A 58118 B ARCS LOW B ARCS HI B ARCS LOW A ARCS HI A SB218 B ARCS LOW B ARCS HI B ARCS LOW A ARCS HI A 58218 B ARCS LOW B ARCS HI B ARCS LOW A ARCS HI A dV SUB B ARCS LOW B ARCS HI B ARCS LOW A ARCS HI A dV SUB B ARCS LOW B ARCS HI B SB218 A SB218 A SB218 A 58218 A 58218 A SB218 A SB218 A SB218 A SB218 A SB218 A FULLRANGE A SB218 B FULLRANGE B B218 MONO MONO A B FULLRANGE A 58218 B FULLRANGE B B218 MONO A B MONO A B Table 14 BSS FDS 366 Presets PRESET NAME PGM TYPE 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 5 A I B 5 A I B 5 A I B 5 A I B 5 A I B 5 A I B 2 2 2 2 2 2 1 C 3 A 2 A 1 C 3 A 2 A 2 2 4 A 2 B 2 4 A 2 B 2 2 1 C 3 A 2 B 5 5 5 A I B 5 A I B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 5 A I B 5 A I B 5 A I B 5 A I B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A 3 B 3 A
53. M If a circle of radius d is centered at M it intersects source i Recalling the condition that dd 2n 1 2 2 a second circle can be drawn with a radius of d 4 2 i e n 0 in the expression for the path length difference If adjacent sources are inside the ring defined by d 4 3 2 then they do not cause cancellation they couple constructively If sources outside the ring they may cause cancellation L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 144 of 158 Decrease f Increase f Figure 104 The effect of varying frequency and listener position M on Fresnel rings As seen in Figure 104 when decreasing the frequency while maintaining the same listener position wavelengths get larger and the ring spacing gets bigger so that more sources fall within the ring and couple constructively at M Conversely as the frequency increases fewer sources fall within the ring and add constructively at M Maintaining the same frequency and therefore the same ring spacing and moving the position M closer to the array means that the radius of curvature of the rings is decreased therefore fewer sources fall within the ring Moving the listener position further away the radius of curvature increases and more sources fall within the constructive ring Now let s draw all circles with radii defined by 2n A 2 The destructive areas where cancellation occurs are shown in gray in Figure 105 White areas are construct
54. OO gt 62 OUT 3 Im OUT 4 __ 1 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 138 of 158 Table 18b 24 W6 Socket Assignments W6 W6 XLR CACOM CACOM PROCESSOR LOUDSPEAKER x COLOR PIN CHANNEL PIN CHANNEL ARRAY CODE 981 6 38 BUE C3 2 E uu 36 Brack 62 35 BROWN C2 2 RIGHT amp 34 C2 1 rF 33 RED Ct SB __ 2 fof lt ey FILERE RIGHT 30 BLUE 6 2 P J 2WAYFLHF RIGHT 29 GND C6 1 2WAYFILLHF RIGHT 28 RED C5 3 U 2WAYFILLLF RIGHT 27 BROWN 55 2 T 2WAYFLLLF RIGHT _ 20 C5 1 5 J 2WAYFLLF RIGHT _ 25 GREEN 04 3 D C HF RIGHFRIGHT 24 WHITE 2 D B RIGHFRIGHT 23 1 A HF RIGHT RIGHT 27 GREEN 3 D F MD RIGHTRIGHT 20 YELLOW 2 D E RIGHT RIGHT 19 1 D RIGHTRIGHT L 18 GREEN D2 3 LE
55. SB218 subwoofers the low frequency response of the V DOSC system is extended down to 25 Hz The SB218 subwoofer enclosure has been specifically designed to complement V DOSC and all OEM factory presets are optimized for the 58218 The 58218 contains two 18 transducers front loaded in an optimally tuned and vented enclosure Power handling is 1100 Wrms continuous program 4400 Wpeak at a nominal 4 ohm impedance Connection is made via Speakon NL4 connector and DOSUB cables are used to connect to amplifier racks one SB218 per LA48a amplifier channel Usable frequency response is 28 to 40 Hz 3 dB with 10 dB response at 25 Hz referenced to the average level of the usable response The SB218 features critically damped tuning characteristics with an enclosure tuning frequency of 32 Hz The central large area port enhances large signal dynamic capability while minimizing non linearity due to port turbulence effects 18 transducers employed in the 58218 have a 4 5 inch diameter edgewound copper ribbon voice coil 9 mm peak excursion capability weatherproof cone body diecast aluminum frame massive vented magnet structure and utilize advanced high temperature adhesives in their assembly Loudspeaker components feature low thermal power compression long term reliability and low distortion output The 58218 is constructed of 24 mm baltic birch and is internally braced with steel corner plates and joints that are sealed
56. Separating signal distribution lines to individual L L L R and R R arrays is also an effective way to avoid potential ground loop problems 1 12 CO6 CONTROL OUTPUT PANEL The Control Output panel is a scaled down 6 channel version of the 24 channel CO24 panel that is suitable for 2 way or 3 way stereo FOH or fill delay system applications CO6 is intended for use with a 2 in x 6 out or 3 x 6 Digital Signal Processor DSP for the creation of a compact modular drive rack or for standalone master amplifier rack packaging DSP outputs are connected to the 6x female XLR patch bay on the rear side of the panel and these outputs are in turn assigned to the front panel 19 CACOM connector This provides 6 channel multicore return snake system when used with a standard 30 metre DOM30 Cross Link cable For longer cable runs multiple DOM30 cables can be extended using the DOMP adapter 19 male male CACOM adapter The Control Output panel allows for maximum flexibility while providing a scaleable architecture that can be used for small medium and even large system applications since it is compatible with the dV DOSC and V DOSC signal distribution strategy and cabling connector standards DSP INPUTS e LA 2 5 L ACOUSTICS 5 SA SA CO6 CONTROL OUTPUT 7 WS 5232 C RS485 OUT
57. V DOSC HI A ARCS LO B ARCS HI B V DOSC LO A V DOSC MID A V DOSC HI A ARCS LO B ARCS HI B dV SUB V DOSC LO A V DOSC MID A V DOSC HI A 58218 B dV SUB A V DOSC LO A V DOSC MID A V DOSC HI A 58218 dV SUB A V DOSC LO A V DOSC MID A V DOSC HI A 58218 B dV SUB A V DOSC LO A V DOSC MID A V DOSC HI A 58218 dV DOSC LO dV DOSC HI A FULL B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A FULL B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A FULL B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A FULL B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A dV SUB B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A dV SUB B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A dV SUB B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A dV SUB B dV DOSC LO B dV DOSC B dV DOSC LO A dV DOSC HI A SBII8 B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A 58118 B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A 58 18 B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A SBII8 B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A SB218 B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A 58218 B dV DOSC LO B dV DOSC B dV DOSC LO A dV DOSC HI A SB218 B dV DOSC LO B dV DOSC HI B dV DOSC LO A dV DOSC HI A SB218 B dV DOSC
58. V DOSC loudspeaker cable 8 conductor 4 mm conductor cross section 25 m 80 ft length equipped with male female CA COM connectors for connecting V DOSC enclosures to PADO2a or PADO4a DOSUB SUB CABLE Subwoofer loudspeaker cable 5 m 16 ft length with male 8 pin CA COM connector and four NL4 Speakon connectors for connecting 4 x subwoofers to PADO2a or PADO4a DOIOP EXTENSION CABLE Extension cable 10 m length for use with DOSUB 007 DO2W DO3W cables SP 7 F LINK CABLE 2 way fill loudspeaker link cable 4 conductor 4 mm conductor cross section 0 7 m 2 ft length equipped with 2x NL4 Speakon connectors for paralleling 2 way fill enclosures SP7 F CABLE 2 way fill loudspeaker cable 4 conductor 4 mm conductor cross section 7 m 20 ft length equipped with 2x NL4 Speakon connectors for connecting dV DOSC or other 2 way fill enclosures to PADO2a to PADO4a using DO2W and SP25 F CABLE 2 way fill loudspeaker cable 4 conductor 4 mm conductor cross section 25 m 80 ft length equipped with 2x NL4 Speakon connectors for connecting dV DOSC or other 2 way fill enclosures to PADO2a to PADO4a using DO2W and DOFILL CA COM 8 pin male line receptacle to 2x NL4 Speakon connectors 3 m length for use with DO7 or DO25 cables PADO2a PADO4a and 2 WAY 2W A 2W B 2W STEREO COMB connectors for powering 2 way enclosures DO3WFILL CA COM 8 pin male line receptacle to 3x NL4 Sp
59. Version 4 6 29 2005 Page 123 of 158 The desired overall tonal balance depends on both the music program material and the target SPL For typical rock concerts sound pressure levels are 102 105 dBA continuous A weighted and 125 130 dB SPL peak unweighted The only harmless way to reach such levels is to increase the sub low contour since significant increases in the A weighted SPL would eventually become painful for the audience and possibly illegal In general sub low and high frequency tonal balance contours result in a more mix friendly system for modern music however the influence such a system contour has on your board tapes is a another topic for discussion To a large extent tonal balance contours are a matter of subjective taste and personal preference that is related to where the FOH engineer prefers to set his mix balance on the channel strip or on the main PA Some engineers prefer a built in low end bump in the PA others prefer a flat system and using the warmth of the channel strip on the console For program material with lower overall SPL requirements e g speech and classical music changing a traditionally flat tonal balance by boosting the low end is not desirable since peak levels occur only during very short musical transients the Leq is much lower typically 95 dBA or less In addition a prominent bass response would not be accepted from an artistic point of view by most classical music con
60. actual shape of the audience allows the wavefront to be focused so that tonal balance and sound pressure levels are evenly distributed throughout the listening area Although pure cylindrical wave propagation is not always in effect 3 dB reduction with doubling of distance can still be obtained along with extension of the nearfield if WST Condition 4 is respected this is an important aspect of WST and the reason why correct focus of V DOSC on the audience is so important Psychoacoustically nearfield extension allows one to walk a considerable distance from a V DOSC system with only a small difference in SPL due to the system s unconventional attenuation rate Effectively more of the audience experiences nearfield listening enjoying higher fidelity improved L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 16 of 158 stereo imaging and exceptional clarity Subjectively the loudspeakers seem much closer than they are physically and the sound is your face This helps to improve image localization towards the action on stage not the loudspeaker arrays Practically nearfield extension also means that extreme sound pressure levels are not required close to the system in order to obtain acceptable SPLs further back in the venue this is a highly desirable property that results in reduced potential for hearing loss for both audiences and engineers alike Nearfield extension combined with the precision and predictability of V DOSC cover
61. are connected with the text out it is convenient to perform a last minute check to confirm that all values are correct In addition when the array is flown all angle strap labels will be visible from the rear this is useful as a check and makes for a cleaner installation see Fig 95 i Connect all enclosures to the amplifier racks using V CABLEs and V LINK jumpers between enclosures for parallel operation NOTE it is best to connect cables from amp racks to the cabinets first and jumpers last in order to avoid cable reversal Longer cables can be routed over the BUMP2 or secured with a spanset For additional strain relief velcro straps or tape can be used to secure cables to the U pins on every other V DOSC enclosure see Fig 95 Route two ratchet straps through the U pins of the bottom enclosure and over the bumper Orient the ratchet strap so that the ratchet handle is accessible see Figs 95 m n Note as an alternative to ratchet straps spacer blocks can be employed see Figs 95 i iv As a general rule ratchet straps are acceptable when the system is pointing downwards spacer blocks should be used when the system is pointing upwards Remove all dolly pins As the array is flown cabinets will automatically lift off the dollies see Fig 950 Conduct a final inspection to make sure all cabling is correct correct angle straps are in place and securely seated in the flytrack all U pins are fully inserted and all U pin safeties ar
62. are ground stacked and physically separated from the flown V DOSC arrays the preferred preset options are INFRA 4W or X AUX For INFRA and 4W presets crossover points between sub and low sections are 60 Hz and 80 Hz respectively Complementary crossover filtering for these presets helps to avoid phase problems due to overlapping sub and low section operating bandwidths so that subwoofers can be operated with positive polarity whether the system is driven in 4 way mode or with aux sub drive The 4W preset is not recommended for high SPL applications since less low frequency energy is radiated by the flown V DOSC system due to the 80 Hz high pass filter In order to benefit from the available resources of the V DOSC low section the INFRA preset is recommended An additional benefit of the INFRA preset is that time alignment is more forgiving for a greater part of the audience due to the longer wavelengths at 60 Hz and subjectively the subs become more of a delocalized effect due to the lower crossover point If more low frequency energy is desired from the flown V DOSC system X AUX presets can be used For the X AUX preset the V DOSC low section is high pass filtered 30 Hz and SB218s are operated from 25 80 Hz with negative polarity to account for the phase shift that occurs due to the overlap in the operating bandwidths i e the 24 dB per octave low pass filter for the SB218 generates a phase shift of 180 The X AUX preset takes full advant
63. are two levels of qualification QUALIFIED V DOSC TECHNICIAN QVT The tasks of a Qualified V DOSC Technician are equipment preparation array design using ARRAY or SOUNDVISION software based on room dimensions that are either measured on site or determined from architectural drawings system installation rigging assembly cabling system focus preset selection and drive rack configuration system testing tuning and assisting the FOH mix engineer The QVT is a sound technician with demonstrated ability who has been chosen for his or her technical expertise by a given V DOSC Network Partner To be considered a Qualified V DOSC Technician the candidate must meet the following criteria Participated 3 day V DOSC training session on theory and rigging Recommended by recognized CVE see below an official V DOSC Network representative CERTIFIED V DOSC ENGINEER CVE The higher level of qualification is Certified V DOSC Engineer or CVE In addition to satisfying the mission statement for QVTs the CVE has further expertise in the areas of sound design and system measurement as well as extensive real world experience with V DOSC The CVE has a complete theoretical understanding of all WST based systems including V DOSC ARCS KUDO dV DOSC with a full grasp of the operating theories and principles behind all systems Other requirements include demonstrated fluency in ARRAY and SOUNDVISION software use of adv
64. are two types of curved V DOSC array constant curvature and variable curvature For the first case the angle between all adjacent enclosures is constant while for the second case it varies within the defined range of 0 to 5 5 L ACOUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 64 158 Constant Curvature V DOSC Array The constant curvature array is the simplest type of curved V DOSC array The vertical coverage angle is nominally x where is the number of enclosures the array and is the constant angle between adjacent enclosures For example a constant curvature array of 8 V DOSC enclosures can provide a maximum vertical coverage angle of 8 1 x 5 5 38 5 while still satisfying WST criteria Figure 44 shows the influence of array curvature on the A weighted and unweighted SPL for three different constant curvature arrays Note this example is for the purpose of illustrating WST concepts 2 5 and 2 14 degree angles are not available as standard angle strap values aby 90 X 7 5 deg 4 2 5 Sor 112 dB SPL a 106 dB A WT j M ab 90 x 15 deg 8 2 14 118 dB SPL 106 Bh 7j at30m pent M Abr 22 90 x 15 deg 4 5 112 dB SPL 103 dB A at 30m Figure 44 Constant Curvature Array Examples Comparing the two 4 enclosure arrays in Fig 44 90 x 7 5 versus 90 x 15
65. array Raise the front motor to the same height as the rear motor to level BUMP2 and the top V DOSC enclosure Attach a laser and or remote inclinometer on top of the first V DOSC enclosure use the enclosure as a reference for attaching these measurement instruments not the bumper Note When installed and focussed if the system is oriented downwards the top V DOSC enclosure will tend to close against BUMP2 When the system is pointing upwards there will be a small gap between the top V DOSC enclosure and BUMP2 due to mechanical tolerances Always refer to the top V DOSC enclosure as a site angle reference not the BUMP2 bumper Continue to lift the array The two people on either side of the array then use the side handles to lift the second V DOSC enclosure up towards the first enclosure allowing them to connect the angle straps from the first enclosure to the second enclosure see Fig 95 s t Note If the rear motor is raised higher than the front motor while flying the system the cabinets will tend to close automatically making it easier to attach angle straps This is acceptable for smaller systems for larger arrays it is recommended to fly the system flat so that the load distribution between front and rear motors is equal As a reference attach angle straps from flytrack hole 3 to hole 3 between cabinets to provide the correct inter enclosure angles When using the 0 75 degree angle strap to obtain 5 5 degrees attach the
66. combined response of low and sub sections are discussed in the following along with subwoofer arraying techniques and overall sound design recommendations For additional information please refer to Section 1 15 for details sub low preset processing General Guidelines for the Use of Subwoofers The number of subwoofers required depends on 3 parameters Number of V DOSC Enclosures the standard subwoofer ratio is 5 V DOSC 58218 for example 3 2 6 4 9 6 12 8 15 10 of Program Material the standard ratio is recommended for most rock and pop applications For intense heavy metal or rap 1 1 ratio is desirable a 2 1 ratio can be acceptable for some applications e g corporate special events and in some cases V DOSC can be used without subwoofers e g classical music or speech reinforcement Type of Installation For open air applications the recommended quantities remain standard when subwoofers are ground stacked When subwoofers are flown additional ground stacked subwoofers may be required see below hybrid flown stacked subwoofers In terms of processing two cases can be considered depending on FOH mix engineer preference and the intended purpose of the subwoofers For some applications subwoofers are used as an effect and are not driven with the same signal as the V DOSC system separate auxiliary send The other option is to use subwoofers as a low frequency extension of the V DOSC array an
67. configurations physicall separated AUX SUB drive be implemented using Input Output 6 by using the 58218 DELAY ARC 80 Hz or 58218 LCR 80 Hz presets subs with positive polarity 4W PRESET Align 58218 dipl peak 2 with V DOSC low section File C HLS HSTUPZSTIHERL AH SUBL PK3 FRQ 8 27 ZBH3 PH File C HLS HSTU7 TIHERL AH LOUH 8 27 2BB3 6 85 PH Transfer Function Hag dB 8 38 oct Impulse Response volts to Uri mU 5r 20 0 100 40 0 50 0 log Frequency Time msec Figure 38 4W preset time alignment procedure L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 55 of 158 X PRESET The X preset features the same operating bandwidth for 58218 subwoofers and the V DOSC low section 58218 25 200 Hz V DOSC low 30 200 Hz X presets take full advantage of the available power resources of the V DOSC low section and are intended for closely coupled applications where 58218 subwoofers are installed in close physical proximity to V DOSC flown beside or stacked directly underneath as an extension of the system The X preset optimizes the overall sub low output of the system and provides the best repartition of resources between sub low and high sections The X preset is intended for closely coupled subwoofer V DOSC configurations minimum physical separation AUX SUB drive can be implemented using Input B Output 6 see also X AUX below or
68. consists of 16 V DOSC per side and there are 12 V DOSC for the LL RR arrays Four delay positions of 9 V DOSC each are located on a circular radius 80 metres from the stage The main L R system is focused to 120 meters LL RR are focused to 110 metres and delay system coverage is from 100 150 meters m E A i E 7 m gt 1 g oat Pa it um ram a a Figure 87 SOUNDVISION simulation for a LL L R RR V DOSC FOH system with 4 delay positions L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 107 of 158 M om LE IL dla EE Figure 90 Flown V DOSC delay system Radiohead Oxford 2003 sound design F Bernard L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 108 of 158 4 INSTALLATION PROCEDURES In the following sections detailed installation procedures for stacking and flying V DOSC are presented Please follow these procedures carefully and at all times remain safety conscious In addition e Only users with sufficient rigging knowledge should attempt to install any L ACOUSTICS loudspeaker system intended for overhead suspension e Users should be familiar with the rigging techniques and safety considerations outlined in this manual prior to installation e The V DOSC rigging system is designed to comply with European Community regulations please see the CE conformity declarations in the appendix for specific recommendations
69. distribution panel with Ix 84 pin MASS connector for connection of MULTI return snake from 4x 19 pin male CA COM for distribution of Left Left Left Right Right Right signal lines male female 4 pin XLR pair for distribution of amplifier remote control MC28100 MULTI CONDUCTOR CABLE 24 pair multi conductor return snake 100 m 325 ft length fitted with 84 pin MASS connectors at each end used for connecting CONTROL OUTPUT panel typically located at FOH to MULTI DISTRO panel for signal distribution to the amplifier racks PCMCIA CARDS Contain OEM factory preset data for programming DSP units PCM224V PCM226V and PCM366V for XTA DP224 DP226 and BSS 366 respectively Other approved DSPs are programmed via computer download of preset data Lake Contour BSS Soundweb DOM2 AMP LINK CABLE 6 pair multi conductor cable 2 m 6 5 ft length with 2x female 19 pin bayonet CA COM connectors for distributing signal from CO6 or MULTI DISTRO panels to amplifier racks and for linking AMP RACKS DOM30 CROSS LINK CABLE 6 pair multi conductor cable 30 m 100 ft length with 2x female 19 pin bayonet CA COM connectors for cross stage connection from MULTI DISTRO panel to amplifier racks or for use as a return snake for smaller system configurations DOMP ADAPTER 19 pin male male CA COM adapter for connecting two AMP LINK or CROSS LINK cables when longer lengths are required DOMM LINK BREAKOUT Multipair cable adapter with
70. for the L ACOUSTICS 22 amplifier rack PADO2a plus 2 x LA48a are as follows V DOSC LO V DOSC LO DO10P DO2W or or or DO25 DO10P DOSUB DO7 or 25 DOFILL or DO2W CC4FB SP7 Y J 9 3 V DOSC 4 SB218 or dV SUB 6 dV DOSC ARCS XT Figure 28 LLACOUSTICS RK122a amplifier rack channel assignments and cabling for V DOSC presets Operating modes amplifier rack channel assignments and cabling plus loudspeaker enclosure combinations for the L ACOUSTICS 24 amplifier rack PADOd4a plus 4 x LA48a are as follows AY DO10P DO2W DO10P DO2W 00508 00508 DO7 or 25 DOFILL DO7 or 25 DOFILL or or DO2W CC4FB SP7 25 DO2W CC4FB 7 3 V DOSC 3 V DOSC 4 SUBS 4 SUBS ll 11 6dV DOSC ARCS XT 6dV DOSC ARCS XT Figure 29 L L ACOUSTICS RK124a amplifier rack channel assignments and cabling for V DOSC presets L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 46 of 158 To power 2 way fill enclosures or 3 way stereo dV DOSC ARCS XT systems using PADO2a and PADO4a amplifier panels additional COMB connectors can be employed 2W A 2W B 3W A 3W B SUB A SUB B or 2W STEREO DSP output channel assignments for 2 way stereo and 3 way stereo format presets 6 CO24 patching and COMB connector channel selection are summarized as follows Table 8 2 way and 3 way stereo preset DSP output channel assignme
71. in a V DOSC or SOUNDVISION Training Seminar is recommended UPSTAGE MOTOR DOWNSTAGE MOTOR Z AXIS HEIGHT 05 BUMP Y SITE ANGLE 1 ANGLE NEXT Y ARRAY SITE ANGLE 2 HEIGHT ANGLE 2 TO NEXT BUMPER Jaj Y ELEVATION ER SITE ANGLE 3 TE amp p ANGLE 3 NEXT Wi 5 g SITE ANGLE 4 47 ARRAY DEPTH ELEMENT gt ELEVATION FLOOR LEVEL Y Y REFERENCE ORIGIN Figure 51 SOUNDVISION Geometric Data for V DOSC L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 77 of 158 kHz 2 kHz 10 kHz Figure 52 Plan view SPL mappings at octave band frequencies for 12 V DOSC 30 metre throw distance enclosures perpendicular to target plane L ACOUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 78 158 Impact Coverage A Weighted SPL Map 1 10 kHz SPL Figure 53 Impact coverage and SPL mappings unweighted A weighted 1 10 kHz bandwidth for 12 V DOSC 30 metre throw distance enclosures perpendicular to target plane L ACOUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 79 158 SOUNDVISION EXAMPLES A full description of SOUNDVISION is beyond the scope of this manual however two examples are presented in the following before turning to a more general description of V DOSC sound design SOUNDVISION STADIUM EXAMPLE The following SOUNDVISION example Amsterdam Arena NL s
72. optimally in the field L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 18 of 158 THE V DOSC SYSTEM STANDARD V DOSC is a complete self contained FOH sound reinforcement system consisting of V DOSC enclosures and accessories rigging hardware 58218 subwoofers approved digital signal processors with OEM factory presets L ACOUSTICS LA48a power amplifiers power amplifier racks PADO2a or PADO4a panels CO6 or CO24 signal distribution panels loudspeaker and signal distribution cables V DOSC system elements have been carefully selected by L ACOUSTICS for their specific quality and long term reliability The benefits of a system standard include Cross rental compatibility between V DOSC Network Partners High standards of quality control Consistent system performance worldwide Reduced procurement time no need to build panels racks etc Long term common experience shared by QVTs and CVEs Enhanced end user confidence artist FOH engineer production The V DOSC system standard does not include chain motors mains distribution or external handling gear nor does it include upstream signal mixing and processing equipment In general the V DOSC system is capable of producing sound from a line level signal in any concert situation System block diagrams are presented below to provide an overview of system connection and signal flow This is followed by an identification of the individual elements of the system and
73. or for powering passive enclosures DSUBTK PADOSEC Mains distribution panel 32 amp connector 5x AC receptacles L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 27 of 158 PADOSEC PADO2a COMB CONNECTOR PADO4a 24 Figure 14 Amplifier Rack Options and Accessories L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 28 of 158 SIGNAL DISTRIBUTION AND CABLING 26 27 28 29 30 31 32 33 34 35 CONTROL OUTPUT PANEL Control Output Panel for use with a single 2 in x 6 out or 3 x 6 digital signal processor DSP to create a compact modular drive rack or for mounting RKI2U amplifier racks along with amplifiers and a DSP unit for standalone master rack applications DSP outputs are connected to the 6x female XLR patch bay on the rear side of the CO6 panel and then assigned to the front panel 19 CACOM connector to provide 6 channel multi conductor return snake system when used with DOM30 Cross Link cables CO24 CONTROL OUTPUT PANEL Control Output Panel for use with four 2 in x 6 out or 3 x 6 DSPs to create a system drive rack 84 pin MASS connector 4x 19 pin male CA COM connectors 24x female XLR inputs on the internal side x male female 4 pin XLR pair for amplifier remote control monitoring Used for connecting DSP outputs and amplifier remote control monitoring to MC28100 MULTI return snake lines MD24 MULTI DISTRO PANEL Stage
74. other line arrays are compared to and has become a modern day classic But V DOSC is not just a speaker it is a standard system and through the V DOSC Network a worldwide service including highly trained technicians over 1 500 people have been through V DOSC and dV DOSC training as of this writing V DOSC is a mature proven system that will continue to benefit from ongoing evolution and improvements with a strong emphasis on technical support through training modeling project support and R amp D In closing it has been an honor and a pleasure to work with V DOSC over the years and a few thank you s are in order Dr Christian Heil Professer Marcel Urban Joel Perret Herve Le Gall the L ACOUSTICS R amp D team Christophe Pignon Christophe Combet Jacques Spillman and the L ACOUSTICS Technical Support team Bernie Broderick Cedric Montresor and Dave Brooks All V DOSC Network Partners V DOSC Trainers CVEs and QVTs around the world You re too numerous to thank individually but my sincere thanks for your hard work and support over the years Paul D Bauman June 2005 Hmm What s next For those interested The Tipping Point by Malcolm Gladwell is a book that describes how trends spread Makes for a good bus read L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 4 of 158 TABLE OF CONTENTS TABLE OF CONTENTS 5 LIST OF FIGURES UE DA EID DEI ep Luc 8
75. over the entire HF bandwidth 1 3 18 kHz This is achieved by mounting a DOSC waveguide on the exit of each driver this shapes the wavefront into a rectangular constant phase source Arraying DOSC waveguides and drivers then creates a flat isophasic ribbon that fulfills the first WST criterion i e the overall radiating area is more the 80 of the target area provided that the angle is less than 5 degrees between enclosures L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 148 of 158 APPENDIX 4 HOW DOES THE DOSC WAVEGUIDE WORK The DOSC waveguide is the result of careful analysis of the wave path from the exit of a compression driver through the waveguide and the resulting wavefront shape at the exit of the device CONICAL HORN CONSTANT DIRECTIVITY HORN Figure 109 Horn Generated Wavefronts With respect to Figure 109 the wavefront emerging from a horn is the result of constant time arrivals for all possible wave paths radiated by the driver exit The two examples shown in Figure 109 produce more or less curved wavefronts that obviously cannot meet the first WST criterion Figure 110 DOSC Waveguide Internal Section By comparison the DOSC waveguide acts as a time alignment plug delaying the arrival times of every possible wave path to be the same value at the rectangular exit of the device The internal plug is a truncated conical piece that looks like a tomahawk This plug and its outer housing are precisely co
76. straps from flytrack hole 3 to 2 Always make sure you have a solid physical mating between the double stud fitting and the flytrack do not hold the plunger out simply place the fitting into the flytrack then slide the fitting into positon and listen for a loud click Physically shake the angle strap to ensure that a secure physical connection has been obtained Optional Spacer blocks can be inserted on each side by attaching the hook and safety on the bungee cord between cabinet handles then pushing the spacer backwards towards the rear of the enclosures so that they are tightly wedged in between the boxes and all slack is taken out of the angle straps see Fig 95 aa dd Note Ratchet straps or spacer blocks are required since as enclosures are added to the array the weight of the array tends to flatten the site angles of individual enclosures Spacer blocks maintain the same inter enclosure angles whether the system is oriented upwards or downwards The array is progressively raised and this procedure is repeated until all angle straps and spacer blocks have been connected to all enclosures Note Up to 8 dolly boards can be stacked using the technique shown in Fig 95 u It is a good idea for someone to guide the array from behind as the system is flown rotating legs on the bottom cabinet are useful as handles for this purpose Pay particular attention to steady the bottom enclosure as it lifts off since it will tend to flip f
77. subs with inverted polarity 3W INFRA PRESET The 3W INFRA preset features a 60 Hz HPF for the V DOSC low section along with optimized low section shelving equalization Compared with the 3WX preset 60 Hz high pass filtering provides additional over excursion protection for the V DOSC low section INFRA preset is intended for standalone applications without subwoofers or for AUX SUB drive using the 58218 DELAY ARC 60 Hz 58218 LCR 60 Hz presets subs with positive polarity L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 53 of 158 4 PRESETS SUBWOOFER TIME ALIGNMENT RECOMMENDATIONS As of the Version 7 preset library release sub low sections have been pre aligned for 4 way and 5 way presets in a closely coupled measurement configuration i e ground plane measurements were conducted on a stack of 3 V DOSC 2 SB218 and all sub channel delays were pre aligned for this configuration to obtain optimum summation Therefore when V DOSC is flown and subs are ground stacked all that is required is to measure the geometric physical path difference at your reference point of choice and add this to the standard pre aligned sub delay If using Bushnell Rangefinders to measure the path difference the accuracy corresponds to meter so the geometric starting point can be varied by 3 msec to verify optimum summation Pre alignment allows for quick and easy subwoofer time alignment for those who don t hav
78. the array to ensure that closest members of the audience are covered Connection of the array to the amplifier racks can be performed as soon as stacking is complete To avoid confusion connect cables to the amplifier racks first and parallel jumpers between V DOSC enclosures last this way reversal of cable sex is avoided i e the output of the rack is female which can be confusing to the average stagehand Remember to parallel 3 V DOSC enclosures maximum When unstacking the array first remove all loudspeaker cabling As V DOSC enclosures are unstacked remove the spacer blocks first since this makes it easier to remove the U pins when disconnecting the rotating legs Dolley boards can be attached and enclosures directly unstacked onto their wheels L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 110 of 158 SAFETY RULES NO MORE THAN 6 V DOSC ENCLOSURES SHOULD BE STACKED ON ONE 2 ALWAYS ATTACH ROTATING LEGS AND ANGLE STRAPS BETWEEN ENCLOSURES Test the strength of the supporting floor and if necessary use plywood sheets or steel plates under individual screwjack feet in order to help distribute the load The maximum downward or upward tilt angle of the bumper is 2 degrees When stacking on scaffold platforms install 2 rear screwjacks only for downwards tilt and ratchet strap the BUMP2 to the platform for improved stability see Figure 91 USE TH E A Pee ELS Doe
79. the separation between the stacked L R subwoofer arrays is approximately 4 5 6 metres they will also act as a centre channel in conjunction with the flown L R subwoofers to create an LCR configuration with the accompanying benefits of more even horizontal coverage see 3 5 2 As a time alignment reference for FOH L for example the measurement microphone should be located between the flown L and stacked L subwoofers and at a distance where the energy from the flown and stacked subwoofers is identical Such a time alignment reference provides the most even horizontal coverage combined with a smooth transition between flown versus ground stacked subwoofers with distance Figure 74 Hybrid flown stacked subwoofer example 14 V DOSC 3 dV DOSC per side flown dV SUB 6 per side ground stacked 58218 6 per side LL RR 4 V DOSC 6 dV DOSC per side stereo infill 2 dV DOSC per side distributed front fill 4 dV DOSC Bjork POPB Paris 2003 sound design Malki L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 96 of 158 3 5 SUBWOOFER ARRAYING TECHNIQUES 3 5 1 LEFT RIGHT CONFIGURATIONS Any L R subwoofer array will have problems with the so called power alley effect i e a build up of low frequency energy in the centre accompanied by uneven low frequency response and impact off axis in the horizontal plane This is easy to understand using Fresnel analysis i e in the centre the distance to L R arrays is identica
80. 0 757 1 37 27 4 or 5 5 The following chart indicates the safety factor under the above conditions For all conditions always refer to the V DOSC OPERATOR MANUAL Version 3 2 or later and the safety conditions indicated by L ACOUSTICS ARRAY software P lt SITE lt 10 61 Kg 134 6 Ibm 771750 daN 3934 Ibf _ The rigging structure BUMP is designed for the suspension of L ACOUSTICS V DOSC loudspeakers only in accordance with published L ACOUSTICS instructions Up to 16 V DOSC be suspended vertical column below the BUMP2 rigging structure when used as a suspension frame using 2 rigging points front rear Up to 6 V DOSC enclosures can be stacked when using the BUMP2 structure as a stacking platform Adjacent V DOSC enclosures are securely attached to each other and to the BUMP2 rigging structure using 2 stainless steel U Shaped pins DOAXE Two ANGLE STRAPS are attached to the side mounted aluminum track on each side of the V DOSC enclosure and are used to set the angle between adjacent enclosures ANGLE STRAPS are constructed of 2 double stud aircraft fittings that are attached with shackles to a steel bar and are normally not load bearing elements of the rigging system The design testing and quality control assurance procedures for the BUIMP2 rigging accessory were validated with the participation of the WELDING INSTITUTE an independent French inspection office Technical Reports 4063
81. 0 and 40167 These reports are part of the development documentation for BUMP2 and are reserved for L ACOUSTICS internal use L ACOLISTICS has engineered the BUMP2 rigging accessory using state of the art modeling and calculation software The BUMP2 rigging accessory was also destructively tested to validate its final design using a pulling bench equipped with laboratory calibrated measuring cells L ACOUSTICS hereby declares that all the above product conform to The Machinery Directive 98 37 Part 4 Lifting Accessories 2 Rules for the Design of Hoisting Appliances European Federation of Materials Handling and Storage Equipment FEM 1 001 Established at Marcoussis France on the 137 of August 2003 Signature of L ACOUSTICS representative se ap etree 1 Hie Leva hoine Jacques Spillmann cid Chief Engineer Manufacturing 41 31 64 DCE BLIME paga 1 2 DCE BLIME paga 2 2 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 156 of 158 DTI TET DECLARATION OF CE CONFORMITY Standards conformity L ACOUSTICS has engineered the BUMPDELTA rigging accessory using state of the art modeling and calculation software The BUMPDELTA rigging accessory Description Rigging accessory for the was also destructively tested to validate its final design using a pulling bench BUMP rigging structure equipped with laboratory calibrated measuring ce
82. 18 i LO 5 way A B 40 dV SUB A V DOSC LO A V DOSC MID A V DOSC HI A 5 way 5 way V DOSC dV SUB SB218 X 5 way a a a es p ee ee SB218 DELAY ARC 60 HZ 44 SB218 MONO A B MONO A B Table 12 XTA DP226 Presets L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 60 of 158 LAKE CONTOUR V DOSC PRESETS 3 WAY MODULES continued V DOSC 3W i LO V DOSC LO A V DOSC MID A V DOSC HI V DOSC LO B V DOSC MID B V DOSC 3WiHI V DOSC LO A V DOSC MID A V DOSC HI A V DOSC LO B V DOSC MID B V DOSC 3W 80 Hz LO V DOSC LO A V DOSC MID A V DOSC HI A V DOSC LO B V DOSC MID B DOSC 3W 80 Hz HI V DOSC LO A V DOSC MID A V DOSC HI A V DOSC LO B V DOSC MID B V DOSC LO A V DOSC MID A V DOSC HI V DOSC LO B V DOSC MID B z V DOSC LO A V DOSC MID V DOSC HI A V DOSC LO B V DOSC MID B 4 WAY MODULES lt lt lt og OJO g lt 1 lt 1 lt 1 lt 1 lt 01010 0 0 0 0 10 4 nnn xix 212 V DOSCLO A V DOSC MID Aj V DOSC LO A V DOSC MID A DOSC X LO V DOSCLO A 4 2 MODULES DOSC X dV LO SB218 A V DOSC LO V DOSC MID A V DOSC HI A dV DOSC LO B V DOSC X dV HI SB218 A V DOSC LO A V DOSC MID A V DOSC HI
83. 2 CENTRAL LINE ARRAY WITH ELECTRONIC DELAY PROCESSING 99 3 5 3 LEFT CENTRE RIGHT CONFIGURATIONS 2 2 4 100 3 5 4 LARGE FORMAT SUBWOOFER ARRAY CONFIGURATIONS 102 3 6 COMPLEMENTARY FILL SYSTEMS eus epa 105 EJ EM JB 105 320 2 OFFSTAGE Beet 106 3 6 3 DELAY SYSTEMS 107 4 INSTALLATION PROCEDURES 109 A STACKED SYSTEM m 109 4 2 FLOWN 5 112 5 V DOSC SYSTEM OPERATION 123 5 1 SYSTEM TONAL BALANCE ssiccisscvelsscsusicsewasucsesinnnesddaseesesstdssdedeussssscsovessisedevsdsdeesvesdusvesdeusdssacsss 123 5 2 MEASUREMENT PROCEDURES 125 Measurement Instr ments eere cveccessseoosdeusscossectseceens 125 126 Step By Step Tuning 256 127 6 MAINTENANCE AND INSTALLATION 85 1 129 6 1 Recommended Maintenance Procedures
84. 2185 are processed in X AUX mode For flown dV SUB ground stacked 58218 configurations dedicated X and INFRA presets are available see Section 1 15 Figure 73 shows two options for the ground stacked subwoofers in both cases 58218 enclosures are standing vertically on their side This orientation is beneficial for two reasons all of the central ports are aligned horizontally this provides optimum port coupling plus low frequency output at the port tuning frequency approx 30 Hz 2 when oriented in this manner the 58218 is at a convenient height to serve as a stacking platform for front fill or stereo in fill enclosures As an alternative to the central line configuration individual 582185 can also be spaced apart and used as part of a distributed front fill system see Fig 78f A central line array of SB218s will radiate omnidirectionally into half space vertically this is of interest for indoor venues in order to obtain low frequency impact throughout the tribune section of the audience Horizontal coverage of the central line array can be improved with additional electronic delay processing see Section 3 5 2 and overall flown L R plus ground stacked subwoofers form an LCR configuration with the potential for improved low frequency coverage in the horizontal plane The stacked L R subwoofer configuration shown in Figure 73 proves a convenient location for stereo infill enclosures for example dV DOSC or ARCS Provided that
85. 5 doc 83 158 Full System dV DOSC Offstage LL RR FOH L R I 12XT Front Fill System Figure 59b Arena example plan view of 1 10 kHz SPL mappings L ACOUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 84 158 3 SOUND DESIGN 3 1 STACKED OR FLOWN Although flown systems are generally preferred there are good arguments to support both solutions and in some cases the choice is dictated by the venue itself i e sometimes it isn t possible to fly the system since rigging points are not available or weight restrictions apply Stacked Systems improve image localization for the audience since the perceived sound image is lowered to stage level This is beneficial in small venues and stacking also offers more low frequency energy due to enhanced ground coupling Since V DOSC has less SPL attenuation from front to rear of the audience than traditional systems this allows a stacked system to project further and provide better underbalcony penetration in theatres and clubs for example In addition for geometric reasons a stacked system can provide more extended vertical coverage than a flown system this can be seen using ARRAY 2004 or SOUNDVISION and is simply related to the geometry of the audience to be covered For example distributed field level stacked systems are an excellent solution for stadium sound reinforcement fewer enclosures are required to obtain the necessary audience coverage vertically and as an
86. 7 the same unweighted SPL will be observed at 30 m since both arrays contain the same number of 15 loudspeaker components and the unweighted SPL is largely determined by the amount of low frequency energy However a 3 dB increase in the A weighted SPL will be observed for the 90 x 7 5 array since the same amount of mid high energy is focused over half the vertical angle i e 7 5 versus 15 Comparing the two 90 x 15 coverage arrays 4 versus 8 enclosures for the 8 enclosure array there will be a 6 dB increase in the unweighted SPL since there are twice as many 15 loudspeaker components and a 3 dB increase in the A weighted SPL since twice as much mid high energy is focused over the same solid angle Finally when comparing the 4 enclosure 90 x 7 5 array versus the 8 enclosure 90 x 157 array it is interesting to note that it is possible to obtain the same A weighted SPL using half the number of V DOSC enclosures By focusing half the amount of mid high energy 4 enclosures versus 8 over half the vertical angle i e 7 5 versus 157 the same A weighted SPL is observed at 30 m for both arrays Note Since a constant curvature array radiates the same amount of energy in all directions over its nominal vertical coverage angle of N I x this type of array is of practical use only when the entire audience is sitting at the same distance from the array However in most venues a V DOSC array will have to cover an audie
87. A dV DOSC LO B 2 MODULES OUTPUTS 5 6 UX FULL B ARCS LO B ARCS LO B IT2XT LO IT2XT LO B IT5XT LO B 115 LO B IT5XT LO B IT5XT LO B dV DOSC LO B dV DOSC LO B dV DOSC LO B dV DOSC LO B I 12XT FILL 112 FRONT 1 15XT FILL I15XT FRONT 15XT FILL 15 FRONT V DOSC 2W 80 LO V DOSC 2W 80 V DOSC 2W 100 LO V DOSC 2W 100 HI e ererer rT gt Dl D gt lt 5 1 MODULES V DOSC Hi V DOSC HI A SV DOSC dV DOSC HI A V DOSC 4W AUX dV LO dV DOSC LO A dV DOSC HI A dV DOSC HI A dV DOSC HI A V DOSC X AUX dV Hi dV DOSC LO A dV DOSC HH A ARCS HI A ARCS Hi A V DOSC X AUX ARCS LO V DOSC LO A V DOSC MID A V DOSC HI A ARCS LO A ARCS HI A ARCS A V DOSCHI A V DOSC dV SUB SB218i HI SB218 A dV SUB A V DOSC LO A V DOSC MID A V DOSC HI V DOSC dV SUB SB218XLO V DOSC HI Aj V DOSC t dV SUB SB218 X Hi V DOSC LO A V DOSC HI Aj 6 WAY MODULES 58218 Table 13 Lake Contour Presets L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 61 of 158 BSS FDS 366 V DOSC PRESETS OUT Source V DOSC MID A V DOSC HI A V DOSC LO B V DOSC MID B V DOSC HI B V DOSC MID A V DOSC HI A V DOSC LO B V DOSC MID B V DOSC HI B V DOSC MID A V DOSC HI A V DOSC LO B V DOSC MID B V DOSC HI
88. B coverage angle is more representative of the effective coverage of a system For a V DOSC array of arbitrary size and shape the 3 dB coverage angle is 70 from 630 to 12 5 kHz This 70 coverage angle also defines the recommended limit for the relative angle between V DOSC arrays for example when main L R FOH V DOSC arrays are oriented at zero degrees offstage LL RR arrays can be oriented at up to 70 relative to the main L R arrays while maintaining a 6 7 metre separation between arrays in order to maximize overall system coverage while reducing the audible effects of interference see also 3 1 Multiple Array Concepts For sound design purposes the horizontal coverage of V DOSC is represented by using an isobaric constant sound pressure curve or isocontour that is obtained by taking the average of individual 1 3 octave polar plots over 630 to 12 5k Hz bandwidth and then re formatting the information on linear scale Unlike a standard polar plot which corresponds to the SPL versus angle referenced to the on axis level at a given frequency the isocontour is more useful for practical coverage prediction Note The 630 12 5 Hz bandwidth is selected for the calculation of the V DOSC isocontour since the horizontal coverage is stable over this frequency range due to the system s coplanar symmetry In addition this bandwidth is representative of the perceived intelligibility and clarity of the system The horizontal projection o
89. Beyond this distance the wavefront becomes spherical and the coverage angle is 6 i e the wavefront at kHz is defined by the height of the array up to 19m and broadens by 3 starting at dhora 19 For a person located less than 19m from the sound source frequencies below kHz are radiated in spherical mode with an attenuation rate of 6 dB per doubling of distance All frequencies higher than 2 propagate in cylindrical mode with an attenuation rate of 3 dB per doubling of distance NEL 2000 Hz 1000 Hz Figure 112 Illustration of dborder and Dv for a flat 12 enclosure array L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 151 of 158 APPENDIX 6 PATTERN CONTROL OF A CONSTANT CURVATURE ARRAY In practice the vertical coverage angle is controlled for frequencies greater than frequency F where 444 A 2 and is the number of enclosures is the constant angle between enclosures degrees At F the vertical coverage angle is equal to the nominal value for the array i e N I x degrees At higher frequencies the coverage decreases to a value which is approximately equal to 2 3 of N x A This defines the minimum vertical coverage angle and is termed the beaming frequency The vertical coverage angle then increases back to the nominal value at F defined by _1 77x10 20 AN For frequencies higher than F the vertical coverage angle is constant For example a
90. CS V DOSC Manual Version 4 6 29 2005 Page 106 of 158 3 6 3 DELAY SYSTEMS The excellent long throw capability of V DOSC often eliminates the need for a delay system and allows the FOH mix position to be located at distances of up to 65 metres for improved audience sightlines However factors such physical obstacles wind sound wave refraction due to temperature and humidity gradients or very large distances gt 120 m may create the need for a delay system Good delay system candidates include V DOSC dV DOSC or KUDO and typically a 4 array FOH system LL L R RR in conjunction with 3 4 delay positions located at approximately 80 100 metres will provide coverage up to 150 metres or more The exact number of delay rings and delay positions per ring will depend on the overall throw distance and horizontal coverage requirements Time alignment and tuning of delay systems in open air situations is not straightforward since the correct delay time setting is typically valid over a limited area and there are also the effects of wind temperature and humidity to consider Despite these variables there are a few guidelines that should be followed when installing delay systems Distributed delays should be positioned along an arc of constant radius centered at the stage in order to geometrically optimize time alignment throughout the coverage region of the delay system 2 Delay systems should be focused to provide approximately 0 20 meters overla
91. DOSC enclosures the V DOSC BUMP2 bumper and angle strap weights only Loudspeaker cables steels and motor weights are not included 2 Calculation of the REAR LOAD is within 20 error When the rear motor load goes to zero Maximum Site Angle is displayed 3 Calculation of the FRONT LOAD is within 20 error When the front motor load goes to zero Minimum Site Angle is displayed 4 2 LEG STRESS refers to the stress on the V DOSC BUMP2 bumper s rotating legs and is accurate within 2096 error NOTE the effect of rear ratchet straps is not taken into account 5 2 ANGLE STRESS refers to the stress on the top enclosure s BUMP angle straps and is accurate within 20 error the angle strap load rating is exceeded there is WARNING indication Note the effect of additional rear ratchet strapping is not taken into account IF YOU ARE APPROACHING A WARNING INDICATION DO NOT OVERTIGHTEN RATCHET STRAPS UNDER ANY CIRCUMSTANCES USE SPACER BLOCKS INSTEAD For more details on ratchet strap issues please refer to Section 4 2 dV ARRAY dV ARRAY2 Input Data Input data and the optimization procedures for dV ARRAY and dV ARRAY2 worksheets are the same as for and V ARRAY2 except for the following differences geometric data and XZ origins are different due to the front pivoting rigging system see figure 49 2 up to 24 dV DOSC can be simulated 3 mechanical data refers to the stress on rear and front pins for the top encl
92. DOSC upfill simulation an autofocus adjust angle of zero degrees corresponds to the first dV DOSC enclosure as parallel to the site angle of the top V DOSC To obtain the O degree relative angle the 3 75 degree hole dV ANGLEP must be used ruring installation For upfill purposes the 5 5 or 7 5 degree holes can also be selected on dV ANGLEP When using 5 5 or 7 5 degree holes set autofocus adjust 1 75 degrees or 3 75 degrees respectively This is necessary to compensate for the 3 75 degree trapezoidal angle of the first dV DOSC enclosure L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 68 of 158 Optimization Procedure After entering all input data as described above press the SCALING button to display the defined audience geometry and vertical coverage of the system The cutview display shows the intersection of individual V DOSC enclosure site angles with the audience square blocks site angle impacts and represents the dispersion of SPL over the audience In accordance with WST Condition 4 the best results are achieved when enclosure site angle impacts have equal spacing between them In this case the SPL decreases by 3 dB when doubling the distance see Figure 47 for details Figure 47 a Cutview showing non constant enclosure site angle impact spacing for an 8 enclosure constant curvature V DOSC array 3 degrees between all enclosures Figure 47 b Cutview showing constant
93. Figs 95 b e Place the BUMP2 bumper at the top of the array The bumper is mechanically connected to the top cabinet in the same way that the cabinets are joined together i e by rotating BUMP2 legs into position on the top enclosure and securing them using U pins see Fig 95 f g Connect the top enclosure to BUMP2 using two BUMP angle straps on the side flytrack sections to secure the top enclosure to the bumper NOTE the site angle for the top enclosure is set by angling BUMP2 during the final step of array angle adjustment see Fig 95 h Referring to the angle strap values that have been pre determined using ARRAY 2004 or SOUNDVISION proceed to connect one end of all angle straps to the flytrack sections on both sides of all enclosures of the array Available angle straps values are 0 75 1 3 2 3 and 4 degrees by moving 0 degree angle strap one hole location closer 5 5 degrees is obtained Although exact flytrack hole location is not critical since the length of the angle strap bar controls the angle between enclosures as a reference you can position angle strap double stud fittings so that the shackle is located in flytrack hole location 3 from the end Orient angle straps so that the ring end of the fitting is facing to the left down once cabinets are flown and the fitting is located at the left side of the flytrack bottom of the flytrack section once flown in flytrack hole position 3 from the end Note If angle straps
94. G SUB D gt AMPS gt 8 AMPLIFIER CHAHHEL ASSIGHMEHT SUB 0 37 SIGNAL XLR COLOR XLR AMP CH AMP OUT SPEAKON COLOR SANA 2 MM AN SWST A 3v ST B ZW STEREO ZW ST 2vv ST B and BROAN LA 48 1 1 BLUE SUB 1 ZW HI AMP1 CH A CHA 1 AMP1 CH A H VIOLET LA 48 2 1 GREEN E SUB 2 LO LO LO LO LO B AMP2 CH A CHA 1 AMP2 CH A F WHITE LA 48 3 RED LO SUB 3 SUB SUB B AMPS A B ORANGE LA 48 4 YELLOVY LO SUB 4 SUB 4 SUB B LO B LO LO AMP4 CH A CHA AMP4 CH A D 7 3 28 CHA 11 4 12 2 3 4 5 6 7 3 VST AN STEREO 2W ST 2W ST B CHB 1 CHB BROAN AMP1 VIOLET AMP2 HITE CH B ORANGE AMP4 CH B CHB AMP3 CH B CHB AMP4 CH B PADO4a AMP RACK WIRING DIAGRAM GHANNEL B CHANNEL A AMP 1 ChB Brown XLR 1 ChA Brown AMP 1 Blue Speakon ame 1 ChA Blue Speakon AMP 2 ChB Violet XLR AMP 2 ChA Violet XLR 2 ChB Speakon 2 ChA Green Speakon AMP 3 While XLR AMP 3 ChB Speakon O
95. I Sections 000 53 Figure 36 Spectral balance for SUB LOW versus MID HI Sections V6 presets and earlier 53 Figure 37 Infra preset time alignment 55 Figure 38 4W preset time alignment procedure 55 Figure 39 X preset time alignment procedure 56 Figure 40 X AUX preset time alignment 56 Figure 41 5W Infra preset time alignment 57 Figure 42 SW X preset time alignment procedure 57 Figure 43a Horizontal V DOSC isocontour averaged from 630 Hz 16 2 63 Figure 43b Horizontal V DOSC isocontour averaged from 32 Hz 630 2 63 Figure 44 Constant Curvature Array Examples 65 Figure 45 Defining Cutview Dimensions 67 Figure 46 Parameters for the ROOM DIM Utility Sheet in ARRAY 0000 68 Figure 47 Cutview showing non constant enclosure site angle impact 69 Figure 47 b Cutview showing constant enclosure site angle impact 69 Figure 47 Plan view representation of non constant a versus constant spacing b arrays 69 Figure 48 ARRAY
96. IGHT RIGHT Figure 32 CO24 Control Output Panel The 24 control output panel can be used in conjunction with 4 digital signal processors to create a compact modular drive rack DSP outputs are patched to the 24 x female XLR patch bay on the internal side of the CO24 panel and are then assigned to 28100 MULTI return snake lines For added flexibility all MULTI lines are paralleled with individual front panel Left Left A Left B Right and Right Right D 19 CA COM connectors These individual CA COM connectors can be used in situations where the drive rack is located onstage eliminating the need for a MULTI DISTRO panel or when it is desirable to run separate drive snakes to remotely located amplifier racks For example in some cases amplifier racks may be located at delay towers behind the FOH location and separate snake runs required or for smaller club theatre shows two DOM30 Cross Link cables can be run for left and right arrays instead of using the 28100 MULTI In addition the availability of individual CA COM connectors allows DOMM LINK BREAKOUT cable to be connected to these outputs for testing purposes The 24 control output panel configuration allows for maximum flexibility while providing a scaleable architecture that can be used for small medium and large systems Let s consider the largest system application in detail since small and medium systems will adhere to the same channel assignment sta
97. L ACOUSTICS 22 9 Figure 7 Example LR System Configuration L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 21 of 158 58218 58218 dV DOSC LL FLOWN L V DOSC L dV DOSC RR Dick 32 V DOSC 2 QO pis CBE iie 5 25 e mo 2 24 qv DOSC TS e 5 3r NaN e 24 58218 Be ONO De 5 gt 5 A 12 LACOUSTICS 24 9 2 L ACOUSTICS 22 TC ae
98. L ACOUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 85 158 Stacking Guidelines The stacking system is rated for a maximum of 6 V DOSC enclosures always use angle straps between enclosures For stacked systems the well defined vertical coverage of V DOSC allows little margin for error Whether the audience is standing or seated is an important consideration and the system should be stacked on a riser of suitable height or on top of subwoofers so that the system is higher than the listening level of the first row of the audience In addition the entire array should be tilted downwards by adjusting rear BUMP2 screwjacks to obtain better high frequency penetration into the audience If the bottom of the array is too low the first rows receive too much SPL and audience members directly in front of the system will shadow the following rows acoustically An additional technique to avoid build up for the closest members of the audience is to install the system further upstage the initial distance attenuation loss to the first few rows will help provide better SPL distribution throughout the entire audience without the need to attenuate the mid or high sections of lower enclosures which will affect the overall output of the system To summarize the bottom of the stacked array should be higher than the audience more than 2 m or 6 5 ft above floor level with the lowest enclosure tilted downwards as necessary For more det
99. L DISTRIBUTION AND 29 LOUDSPEAKER 3 1 2 V DOSC SPECIFICATIONS u cssscssssscsssssssessssssssssesssssssssscssssssscsscssssssssesssssessessssussesscsssssssessessssessees 33 1 3 V DOSG RIGGING SYSTEM iiec en ed eed eie EH ent dee ee 34 1 4 58218 SUBWOOFER SPECIFICATIONS ssssssssssssssssssssssssssscssssssssssssssessesssssssessesssssssesscessesseess 35 1 5 58218 RIGGING SYSTEM c ccssssssssssssssssssscsssssssesssssssssscssssssscsscssssssssssssssessessssussesscsssssssessessssessees 37 1 6 POWERING VD OSG imitate iba deed eH 38 DOSCAMP PANELS 40 1 8 V DOSC AMPLIFIER 43 1 9 COMB CONNECTORS 45 1 10 CO24 CONTROL OUTPUT 49 1 11 MD24 MULTI DISTRO PANEL ERU term det delen 50 1 12 CO6 CONTROL OUTPUT 50 1 13 APPROVED DIGITAL SIGNAL PROCESSORS s sssssssssssssssssssssssssssscsscsscsssssssssssssssscsscssessessesss 51 114 OEM FACTORY PRESETS eet 51 PRESEIS 52 LOUP RESETS 53 3 WAY STEREO PRESEES 53 IWI PRESET e 53 SW
100. LIFIER V DOSC HI SECTION AMPLIFIER REC D POWER OUTPUT REC D POWER OUTPUT REC D POWER OUTPUT LOAD REC D LOAD REC D LOAD REC D ohms POWER ohms POWER ohms POWER 2900 do not use 2700 0 dB 2300 0 dB Note L ACOUSTICS recommends that LA48a Channel A B MLS switches are in the 0 dB position and Channel A B CLIP LIMITERS are enabled rear panel switch IN at all times As standard the L ACOUSTICS LA48a power amplifier has 32 dB gain L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 39 of 158 7 V DOSC AMP PANELS L ACOUSTICS PADO4a AMP PANEL 2 perry 3 s O uuseserkesaserrraaa C CH B SPEAKERS SIGNAL SIGNAL SPEAKERS CH A INPUT OUTPUT CH B e e Figure 22 V DOSC PADO4a Amplifier Rack Panel The PADO4a amp panel allows for connection of loudspeakers input signal and output signal loop through and is suitable for use with 4 LA48a power amplifiers The panel has 2 x female 8 pin CA COM connectors for loudspeaker connection 2 x male 9 pin CA COM connectors for input signal connection and jumping to subsequent amp racks 2 x 37 pin D SUB connectors for attaching COMB connectors that are used to configure the amplifier rack for 2 WAY 3 WAY or SUB operating modes Internally two sets of 4x male XLR fanouts connect the input signal from the COMB connector on PADO4a to the amplifier inputs and two sets of 4x NL4 Speakon line connectors connec
101. Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 120 158 be close to zero with no ratchet when the system is flown and focussed downwards Moderate ratcheting then introduces the possibility of continuously variable angles between 0 to 0 75 degrees and the progression is monotonic as a function of height For example if a 6 enclosure array is pointing 4 degrees down and 0 75 degree straps are used for the first 8 enclosures combined with moderate ratcheting actual values on the order of 0 0 0 25 0 25 0 5 0 5 0 75 0 75 will be obtained for enclosures 1 8 This provides better spacing of enclosure impact zones over the audience in flat open air situations When the array is pointing upwards the centre of gravity shifts forwards and V DOSC enclosures tend to open naturally providing the nominal angle values 0 75 1 3 2 0 3 0 4 0 and 5 5 Therefore for a V DOSC array with upwards tilt very little ratchet strap tension is required Typically the bottom 2 3 enclosures will need to open up slightly and spacer blocks can be used for this purpose or moderate ratcheting To summarize the most precise way to work with ratchet straps is to have a remote inclinometer on top of the array to measure Site Angle and a handheld digital inclinometer to measure the bottom enclosure site angle Fly the array using the angle strap values calculated in ARRAY 2004 or SOUNDVISION and raise the array above ground level at a height where the
102. N U Pin MC DOAXF 2 Left Balancier Cover plastic MP DORAIL G Right Balancier Cover plastic MP DORAIL D Bumper shackle CA MAN22 ANGLE strap shackle CA 8 ANGLE strap fitting CA PION3 58218 Grille Foam CM SUB218 99 58218 Front Grille MC GRSUB218 V DOSC Grille Foam CM DOSC 99 V DOSC Front Grille MC GRDOSC Neoprene glue for grille foam attachment CD COLNEO Brown paint packaged by 10 kg CD TEXTURE Dust filter clips for LA48a Dust filters for LA48a APFILT Rear support kit for LA48a amplifier APSUP Page 130 of 158 6 4 RECOMMENDED INSTALLATION TOOLS FOR SYSTEM FOCUS Digital Inclinometers Handheld Digital Protractor PRO 3600 or equivalent check single point hangs tension ratchet straps measure room dimensions Remote Lucas Anglestar or Rieker RAD2 70 B2 mount on top bottom of the array to tension ratchet straps and set site angle Laser Levels Laserline or equivalent one for each array required FOR DISTANCE MEASUREMENTS Laser Rangefinder Binoculars Bushnell Yardage Pro or equivalent Laser Rangefinder Leica Disto Classic or Hilti PD22 or equivalent 20m 50 ft tape measure for setting array trim height PORTABLE COMPUTER SOUNDVISION Excel for ARRAY 2004 WinMLS SMAART or MLSSA measurement software sound card measurement mic preamp DSP control programming software Lake Contour XTA Audiocore BSS Soundbench2 BSS Soundweb Ay p
103. N Meses 85 STACKED OR FLOWN 85 Stacking Guidelines 86 Flyinge 5 ecc 87 3 2 ACHIEVING OPTIMUM COVERAGE 88 3 2 THE EEFT RIGHT CONFIGURATION poisisissieisccssssnsssccesieseusscassaveusiissccesaestsicoeatecstsssseiestssusstessaseces 88 Tradeoffs Between Intelligibility and Stereo Imaging 2 66 88 3 2 2 LEFT CENTRE RIGHT 1 1 7 1 1 2 1 1 89 3 3 MULTIPLE ARRAY CONCEPTS 90 3 4 SUBWOOFERS 92 3 4 1 Flown V DOSC and Ground Stacked 93 3 4 2 Physically Coupled 5 2 0 95 3 4 3 Hybrid Flown Stacked Subwoofers 2 6 eee eee ee eese eese none 96 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 6 of 158 3 5 SUBWOOFER ARRAYING TECHNIQUES wii csscscccssceosesscsccoossossseccnssoscscsascsessscssaesesssccesessessacnosserssoes 97 3 5 1 LEFT RIGHT 5 222252205000 86045606 97 3 5
104. ODE ANGLE ANGLE 0 75 5 5 0 75 5 5 75 do not use Angle strap values should be selected by taking this degree difference into account for stacked versus flown For example if ARRAY 2004 or SOUNDVISION simulations indicate that a 4 degree angle is required between enclosures and 2 select a 3 degree angle strap for the actual installation Angle differences can also arise due to tolerance variations in enclosure construction and spacer block placement Use a digital inclinometer to determine the effect of these tolerance variations and minimize their impact The same procedure is followed for all other enclosures of the array until stacking is completed NOTE it is easier to place spacer blocks between enclosures as the array is built instead of inserting them afterwards The correct site angle for the entire array is obtained by fine adjustment of the BUMP2 screwjacks Focus can be checked by sight looking from the rear of the array through the small space between the top enclosure and the second one the lower wall of the top enclosure should be aligned so as to aim towards the rearmost seats of the audience Alternatively from the highest section of the audience area if you can see the top of the upper V DOSC enclosure you are out of the coverage pattern Focus can also be performed by placing a laser on the upper wall of the top enclosure and a visual check should be made with respect to the lower wall of the bottom enclosure of
105. SC V DOSC is used with an approved digital signal processor with OEM factory presets for active 3 way 4 way or 5 way operation in conjunction with additional 58218 dV SUB subwoofer enclosures V DOSC RIGGING SYSTEM Dimension WxHxD 1262mm x 140mm x I 100mm lt 49 5 8 x 5 4 8 x 43 3 8 AN Weight 61 5 kg 135 6 Ibs FLYTRACK Figure 18 V DOSC BUMP2 The BUMP2 flying structure consists of a rectangular steel main frame with heavy duty cross bracing and comes supplied with the following rigging accessories 22 mm shackles CA 22 Ix steel sling 0 65 m 4x screwjacks MC DOPIED 2x ratchet straps 16 metre length 2x BUMPER angle straps BUMP23 and 2x U PINS MC DOAXE The two rotating legs located on the bumper along with U shaped locking pins are used to attach the first V DOSC enclosure of the array when either flying or stacking Two side mounted Aeroquip flytrack sections allow for attachment of the first V DOSC enclosure to BUMP2 using the BUMPER angle strap When rigged the BUMP2 is hung from two points spaced by 1 05 m 43 4 one front and one rear The center of gravity of the whole array is exactly vertical from the line joining these two points Motors can be attached to the central hole locations on the bumper or for additional safety factor when flying larger arrays the two outer hole locations front and rear can be used for bridling using 4 steel slings 2 front 2 rear 8 shackl
106. SC enclosure bumper elevation 10 0 m in Fig 94 or lower rear corner of the bottom V DOSC enclosure bottom element elevation 4 78 m in Fig 94 Once the proper height has been set the rear motor is turned off and the front motor used to adjust the site angle of the top V DOSC enclosure 1 5 degrees in Fig 94 see also below SOUNDVISION installation data see Figs 51 and 93 The front motor is used to set the elevation of the array and the rear motor controls the site angle A tape measure should be attached at the upper front corner of the top V DOSC enclosure elevation 10 0 m in Fig 93 or lower front corner of the bottom V DOSC enclosure bottom element elevation 4 73 m in Fig 93 Once the proper height has been set the front motor is turned off and the rear motor used to adjust the site angle of the top V DOSC enclosure 1 5 degrees in Fig 93 see also below NOTE For larger arrays 12 16 V DOSC always fly the system without tilt initially Applying tilt before the array is entirely flown can produce too much stress on angle strap fittings especially if excessive upwards tilt is applied Always refer to the mechanical data provided in ARRAY 2004 or SOUNDVISION to confirm that rigging limits are not exceeded L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 121 of 158 Depending on the tools available there are a number of possible techniques for trimming and angling the array For trim height measurement one
107. STRAPS BUMP23 BUMPER x STUD BUMP24 0 75 5 5 A AIRCRAFT FITTING BUMP251 1 3 SHACKLES BUMP25 2 BUMP26 3 BUMP27 4 Description ANGLE STRAPS for L ACOUSTICS 5 System n Material Aluminum BAR High Grade Steel SHACKLE Cast Steal STUD Product Origin Country of origin of the product France Country of origin for components of the product EEC bp Deitr cthw Tustirig using pollisg bench witfr inbsnriwy cafiberibud culla Standards conformity L ACOLISTICS hereby declares that the above product conforms to The Machinery Directive 98 37 Part 4 Lifting Accessories 2 Rules for the Design of Hoisting Appliances European Federation of Materials Handling and Storage Equipment FEM 1 001 Established at Marcoussis France on the 227 of September 2003 LICOLUATICA 1 Hue Leiche Carica Fontrte de jovenes 5145 tnie Fries T 31 67 53 Ez 31 Wl d 53 Fre rpm a ca xe ED d if EE E Tek VAT FE L ACOUSTICS V DOSC Manual Version 4 Signature of L ACOUSTICS representative Jacques Spillmann Chief Engineer Manufacturing DCE ANGLESTRAP paga 1 6 29 2005 Page 158 of 158
108. STU D5 D STU REMOTE OUT M REMOTE IN F REMOTE IN F REMOTE OUT M 27 REMOTE OUT M 27 REMOTE IN F 28 REMOTE IN F 28 REMOTE OUT M NOTE NOTE REMOTE OUT 4 pin MALE XLR on front panel REMOTE OUT 4 pin MALE XLR on front panel return signal from amplifiers to computer control signal from computer to amplifiers REMOTE IN 4 pin FEMALE on front panel REMOTE IN 4 pin FEMALE XLR on front panel control signal from computer to amplifiers return signal from amplifiers to computer L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 137 of 158 7 5 24 Control Output Panel Line Assignments Table 18a CO24 W6 Pin Assignments ORANGE B 16 G LF 15 WHITE 3 M SUB LEFT E 4 BLUE 2 B L L9 GND 1 B K LEFT 12 WHITE B6 B R 2 WAY FILL HF LEFT 11 BROWN B6 2 B P 2WAYFILLHF X LEFT 4 GND B6 B N 2 WAY FILL HF LEFT 10 BUE 3 B U 2WAYFILLLF LEFT 9 YELLOW 2 B T 2WAYFILLLF LEFT 8 GND B5 1 B 5 WAY FILE LF LEFT _ OUT 1 OUT 2 COLOR PIN CHANNEL PIN CHANNEL ARRAY CODE 2 A L1 A D 34 GND A2 1 A G LF LEFT LEFT 31 RED 3 A R 2 WAY FILL HF LEFT LEFT 30 GREEN 6 2 P 2WAYFILLHF LEFTLEFT 25 RED 4 3 LEFT ORANGE __ 2 Jj Ww NO
109. TERFERE When two sources are physically separated the different arrival times of the wavefronts radiated by the individual sources cause frequency and position dependent constructive and destructive interference Figure 101 The Interference Problem If P is the sound pressure produced by S at point and the pressure produced by S at point M the complex sound pressure P resulting from the addition of the two speakers at point M is calculated as total P e If both sources radiate the same pressure P and the real part of the complex sound pressure at is considered at time t t d c the expression simplifies to i 2 x C where the path length difference d d From the simplified expression it is seen that the second source causes a frequency dependent phase shift given by 09 2 f d c When 2 where 0 1 2 3 integer pressure cancellations occur since cos 2n 1 As a result pressure cancellation occurs for frequencies that satisfy the condition 2f d c 2n where n is an integer L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 142 of 158 For example when 0 33 m i e 0 msec cancellations occur at 500 Hz 1500 Hz 2500 Hz producing what is termed comb filtering The biggest problem with comb filtering is the fact that these cancellations are not consistent with frequency since the time difference changes depe
110. V DOSC the main difference is that within the defined coverage region the interference is constructive while outside it is destructive see Appendix 2 For more details on how V DOSC satisfies WST criteria please refer to Appendix 3 For further information on the DOSC waveguide please see Appendix 4 V DOSC enclosures are vertically arrayed in two or four characteristic J shaped columns Since enclosures of the array couple coherently the enclosures are physically smaller and fewer cabinets are required in comparison with conventional systems This makes V DOSC very cost effective for touring sound applications where transport space and handling time means money These properties also make V DOSC highly effective for fixed installation where compact size combined with predictable coverage is important One of the key benefits of WST is the predictability of the radiated wavefront s shape Horizontally the entire V DOSC array has the same coverage as a single enclosure 90 Vertically the coverage is equal to the sum of the angles used between individual enclosures of the array Given this predictability vertical coverage can be quickly optimized to match the audience geometry using either L ACOUSTICS ARRAY or SOUNDVISION software These convenient user friendly software programs help the operator determine how to focus the wavefront so that tonal balance and sound pressure levels are evenly distributed throughout the audience WST rule 7 4 U
111. Version 4 2005 V DOSC 57 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 2 of 158 FOREWORD This manual is intended for Qualified V DOSC Technicians and Certified V DOSC Engineers who are responsible for the installation and operation of the V DOSC sound reinforcement system It is also intended to provide interested sound engineers designers consultants and installers with information regarding the fundamental principles of Wavefront Sculpture Technology and how these principles are embodied within V DOSC Specifications installation procedures and general guidelines for sound design and system operation are also discussed in this document MANUAL ORGANIZATION The Introduction gives a brief presentation of V DOSC and explains why specialized training is necessary to work with the system Chapter presents the fundamentals of Wavefront Sculpture Technology and introduces the elements of the V DOSC system standard Chapter 2 describes V DOSC array performance and coverage prediction Chapter 3 discusses sound design issues Chapter 4 gives detailed procedures for rigging and stacking V DOSC Chapter 5 describes system operation including preset selection tuning and operation Chapter 6 lists recommended installation and maintenance tools Chapter 7 provides V DOSC system specifications Appendices elaborate a number of technical aspects and provide additional theore
112. With Respect WST Criteria 148 APPENDIX 4 How Does the DOSC Waveguide Work 2 6 149 APPENDIX 5 The Border Between Fresnel And Fraunhofer 150 APPENDIX 6 Pattern Control of a Constant Curvature Array 152 APPENDIX 7 Criteria Number 5 22 csessevsnasceesssdeescdasssccesesaconsscasscsecesdossivcesescccesses 153 APPENDIX 8 Angle Strap Calibration 1c ee Lecce eee ee eee eee eee ee eee ee eee sess sees sese sono ees 154 APPENDIX 9 V DOSC Rigging Certification 0 etes ee 155 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 7 of 158 LIST OF FIGURES Figure Wavefront interference versus a sculptured V DOSC 12 Figure 2 Wavefront Sculpture Technology Conditions and 2 Figure 3 Coplanar Symmetry dd cuu SE RU 5 Figure 4 Cylindrical versus spherical wave l6 Figure QU yr E edie 7 Figu
113. acked L R subwoofers are arranged in a block with minimum frontal surface area and are physically separate from the flown V DOSC arrays either INFRA 4W or X AUX presets are recommended When subwoofers are configured in the manner i e with minimum front surface area or in a vertical column as in Fig 75b there is reduced center build up and fewer horizontal lobing problems compared with the results obtained using two L R horizontal subwoofer line arrays as shown in Fig 75 e Basically interference effects between two omnidirectional sources Figs 75 a b are less dramatic than between two directive sources Fig 75 e Fig 75 b has the added advantage of effectively extending the length of the V DOSC array at low frequencies for improved low frequency pattern control and throw in outdoor open air applications X preset recommended In Figure 75 c the L R subwoofer arrays are configured in an L wrap around the stage corner in an attempt to direct low frequency energy offstage and reduce centre build up Physically curved L R subwoofer arrays as shown in Fig 75 d are a variation on this configuration Figure 75 shows a non recommended configuration since two L R horizontal subwoofer line arrays emphasize the center build up problem In this case the individual L R arrays are more directive in the horizontal plane than the configuration of Figs 75 a and b so that center build up is greater and there are more pronounced horizontal lobi
114. additional benefit the subjective image is lowered to field level Stacking is a good solution for applications where up to 6 V DOSC enclosures can optimize audience coverage low frequency response and image localization Flown Systems are the best solution to achieve uniform sound pressure level and even tonal balance over the audience provided that the number of arrayed enclosures is sufficient to provide the necessary front to rear coverage and that WST Condition 4 is respected i e inter enclosure angles are selected to obtain equal spacing between enclosure site angle impacts over the audience Flying is also an excellent solution for sightline problems that commonly occur Typically the system trim height should be selected to provide a 4 1 ratio between the throw distances to the furthest and closest members of the audience Such a trim height tends to make it easier to satisfy WST Condition 4 and thus obtain optimum SPL distribution Offstage coverage is another consideration when selecting array trim height in general the best results are obtained when the top V DOSC enclosure has a zero degree site angle and is flown at the same height as the highest audience elevation For flown systems additional speakers are typically necessary to cover downfill center fill front fill or offstage fill requirements Good candidates include dV DOSC ARCS KUDO or additional V DOSC arrays see Multiple Arrays Other distributed front fill or stere
115. adiating bass reflex loaded 15 low frequency transducers four bass reflex loaded 7 midrange frequency transducers that mounted in a V shaped acoustic lens configuration and two 1 4 exit titanium diaphragm compression drivers that are coupled to individual vertically aligned DOSC waveguides As a full range system the frequency response 15 50 Hz to 18 kHz with less than 3 dB variation and the usable bandwidth is 40 Hz to 20 kHz 10 dB The DOSC waveguide employed in V DOSC generates a flat isophase wavefront for the high frequency section When vertically arrayed multiple loudspeakers function according to the principles of Wavefront Sculpture Technology with either the separation between acoustic centers of individual sound sources less than the size of half the wavelength at the highest frequency of their operating bandwidth low and mid sections or the sum of the individual areas of the isophasic radiating elements is greater than 80 percent of the target radiating area high section All components of a V DOSC array are symmetrically arranged with respect to a plane vertically bisecting the array coplanar symmetry and provide 90 degree horizontal coverage 6 dB points independent of the number of vertically arrayed enclosures Crossover points are 200 Hz between low and midrange sections and 3 kHz between midrange and high sections with 24 dB per octave Linkwitz Riley characteristics Long term RMS power han
116. age is also effective in pushing back the critical distance in highly reverberant spaces critical distance is defined as the distance in a venue where the energy of the direct sound coming from the system is equal to the reverberant energy coming from the room In many situations it is extremely important to keep energy off the roof for example in arenas or covered outdoor amphitheatres sheds If we can excite less of the reverberant energy in the room and focus more energy on the audience we can effectively move back the critical distance in a given room while offering more of the audience a nearfield listening experience Given the well defined vertical coverage of V DOSC the benefits of WST become immediately obvious in comparison with conventional systems when working in difficult reverberant rooms Finally another benefit of WST is the high degree of SPL rejection obtained outside of the defined coverage pattern Nominally higher than 20 dB this permits the installation of a V DOSC system behind or above microphones with exceptionally high feedback immunity Monitor engineers also enjoy working with V DOSC FOH systems since there is very little backwave on stage even at lower frequencies for larger arrays of up to 16 enclosures vertical pattern control is obtained down to as low as 80 Hz High SPL rejection outside of the defined coverage region also makes V DOSC excellent solution in situations where environmental noise contr
117. age is seen to be stable and well defined above kHz while becoming progressively more omnidirectional at lower frequencies Figure 53 shows impact mode coverage and band averaged SPL mappings for the array of 12 V DOSC enclosures pictured in Fig 52 Impact coverage provides a good representation of the octave band mappings seen in Fig 52 for frequencies higher than 2 kHz For this reason impact mode is L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 76 of 158 considered to provide a good indication as to the overall coverage of the array in terms of clarity and intelligibility It is also interesting to compare the A weighted unweighted and 1 10 kHz SPL mappings of Figure 53 with the individual octave band mappings of Figure 52 1 10 kHz SPL mapping is seen to provide good representation of the overall coverage of the array and also corresponds well with the coverage predicted in impact mode The A weighted SPL average provides a more strict representation of system coverage since there is more emphasis on higher frequencies while the unweighted mapping is more omnidirectional due to the inclusion of lower frequency information in the average Note For color versions of SOUNDVISION figures see the V DOSC manual PDF file available for download on www l acoustics com Note complete description of SOUNDVISION is beyond the scope of this manual Please refer to the SOUNDVISION help file and for further information participation
118. age of V DOSC low section resources and can be implemented using Input B Output 6 for the standard X preset V DOSC 3W or 3WX presets can also be used in conjunction with additional aux sub drive presets for flown V DOSC and ground stacked subwoofer configurations This approach is particularly useful when implementing delay processed subwoofer arrays LCR subwoofer arrays for larger subwoofer array configurations where it is desirable to dedicate a DSP unit to subwoofer drive for additional control and flexibility The 3WX preset features a 30 Hz high pass filter for the V DOSC low section combined with optimized low frequency shelving equalization and aux sub drive can be performed using SB218 DELAY ARC 80 Hz or 58218 LCR 80 Hz presets subs with negative polarity The 3W INFRA preset features a 60 Hz HPF for the V DOSC low section and SB218 DELAY ARC 60 Hz or SB218 LCR 60 Hz presets are recommended for aux sub drive subs with positive polarity L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 94 of 158 3 4 2 Physically Coupled Subwoofers When subwoofers are physically coupled with the V DOSC array flown offstage or stacked underneath with minimum physical separation the preferred preset options are X INFRA or 4W For these configurations the system is normally operated in 4 way mode with the input signal for the subwoofers identical to that of the V DOSC array The X preset is recommended since 58218 subwoofers and the V DOSC lo
119. ails on stacking procedures please refer to Section 4 1 Note When simulating stacked system coverage in ARRAY2004 or SOUNDVISION account for the one degree difference in angle strap values for stacked versus flown systems see Section 2 BAD GOOD vertical Figure 61 Stacked system example Puy du Fou France L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 86 of 158 Flying Guidelines The rigging system is rated for a maximum of 16 V DOSC 15 V DOSC 3 dV DOSC Particular attention must be paid to the height at which the array is flown when predicting the vertical coverage in ARRAY 2004 or SOUNDVISION Typically system trim height should be selected to provide a 4 1 ratio between the throw distances to the furthest and closest members of the audience as a rough guideline the elevation of a 12 enclosure arena system is typically between 11 15 m 36 50 ft depending on the exact geometry of the audience When simulating system coverage using ARRAY 2004 or SOUNDVISION the goal is to select inter enclosure angles so that equal spacing is obtained between enclosure site angle impacts over the audience geometry WST Condition 4 Note inter enclosure angles should not be selected by considering the on axis cutview only always consider the audience coverage off the main axis especially from 35 to 45 on the offstage side It is important to check that you are not lacking in offstage cov
120. ails using U pins Attach two BUMP angle straps to secure the bottom V DOSC and verify the tilt angle for the enclosure using a digital inclinometer use the stacking runner recess on top of the cabinet for alignment of the measurement tool Perform additional tilt adjustment using the bumper screwjacks if necessary L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 109 of 158 A second V DOSC enclosure is then stacked on top of the first and mechanically connected using the rotating legs and U pins in the same way With reference to the installation parameters calculated in ARRAY SOUNDVISION angle straps are connected between the two enclosures and two spacer blocks are then inserted between the enclosures on the sides to set the correct tilt angle for the second enclosure Never use a single spacer block in the center of the cabinets the wood thickness is only 15 mm at this point and the overall weight of the stacked system could cause damage to the bottom enclosures Verify the tilt angle for the second enclosure using a digital inclinometer and fine tune the angle by adjusting spacer block positioning if necessary NOTE Since the rear edges of the cabinets are touching when enclosures are stacked this introduces an additional degree for angle straps when cabinets are stacked versus flown Angle strap values for flown and stacked systems are tabulated below Table 15 Angle Strap Values ANGLE NOMINAL NOMINAL COLOUR FLOWN STACKED C
121. al level 17 dB of headroom remains Since the dBA calculation considers discrete V DOSC enclosures not sections of the continuous radiating line source the resolution of this calculation is not sufficient for the user to attempt to design for constant dBA throughout the audience area Users are advised to refer to the visual spacing between audience impacts and use the dBA estimates as a guideline only In ARRAY GEOMETRICAL DATA cells the physical dimensions of the array are displayed including the Overall Depth of the Array in the x dimension the Overall Height of the Array in the z dimension and the Bottom Enclosure Elevation rear corner of the bottom enclosure referenced to floor level The bottom enclosure elevation is used as a reference for installing the system and the Depth Height information is useful to determine if the array will physically fit in a given space scaffold bay clearance to proscenium wall etc Please see Figure 48 for further details ACOUSTICAL PREDICTION data gives the unweighted SPL of the array at a user selected distance enter the distance in the black cell This calculation is based on a 200 Hz reference frequency and correlates well with the unweighted SPL as opposed to the A weighted enclosure by enclosure SPL estimate The peak unweighted SPL for a single array as well as an estimate of the peak unweighted SPL for 2 arrays is also given Note unweighted SPL estimates do not include additional contr
122. anced measurement tools SMAART WinMLS MLSSA or equivalent for system alignment and tuning full understanding of the finer points of system focus for example tensioning ratchet straps using digital inclinometers angle strap calibration familiar with all preset libraries and software for all supported DSP units familiar with room measurement procedures using laser rangefinders and inclinometers The CVE is capable of recommending endorsing and supervising QVTs during their apprenticeship period towards becoming a full CVE In some cases CVEs may also conduct V DOSC training sessions provided that they have been factory certified as a V DOSC Trainer To be included in the official list that is distributed to members of the V DOSC Network the CVE candidate must meet the following criteria Participated in a 3 day V DOSC training session on theory and rigging Recommended by a recognized CVE or an official V DOSC Network representative Known and certified by an official representative of L ACOUSTICS The Qualified V DOSC Technician and Certified V DOSC Engineer are important representatives of the V DOSC Network While the V DOSC Network provides V DOSC on a rental basis it is the QVT or CVE who accompanies the system at each installation to ensure that system performance is optimal We hope that you will carefully follow the guidelines presented in this manual it is in everyone s best interest that V DOSC is deployed correctly and
123. and the front of BUMP2 laid directly on the stacking surface Conversely when tilting the system upwards rear screwjacks can be omitted Set the BUMP2 azimuth angle to provide the desired amount of array rotation on or off stage If front screwjacks are employed raise the bumper at least 8 cm off the floor by rotating the screwjack wheels CW up CCW down This clearance is necessary to prevent screwjack wheels from physically interfering with the dolly locator studs of the bottom V DOSC enclosure Referring to the installation parameters determined using ARRAY2004 or SOUNDVISION adjust the screwjacks to provide the required tilt angle for the bumper and therefore the bottom V DOSC enclosure NOTE A digital inclinometer is highly recommended for performing angle measurements For stability reasons the maximum bumper tilt angle is 12 degrees so that the centre of gravity of the stacked array remains within the physical footprint of the BUMP2 The lowest V DOSC enclosure is placed on the bumper with the two rotating legs oriented upwards as a reference for cabinet orientation stacking runners on the cabinet should be on the bottom and the rear V DOSC logo in the correct orientation Adjust the front to back position of the enclosure by aligning the Aeroquip flytrack sections of the enclosure with the bumper Mechanically connect the first enclosure to the bumper by lifting the BUMP2 rotating legs up and locking them into the rear V DOSC r
124. any cases dV DOSC downfill enclosures and or a flown centre cluster using ARCS inverted KUDO 110 degree K LOUVER setting or dV DOSC will provide adequate coverage for the closest members of the audience however image localization and coverage can be further enhanced with the addition of a dedicated front fill system Front fill can be provided via stacked stereo infill systems using dV DOSC ARCS or KUDO loudspeakers Alternatively a distributed approach be adopted using dV DOSC MTD XT coaxial enclosures see the MTD XT SPACING worksheet in ARRAY 2004 for a utility that calculates optimum distributed front fill enclosure spacing based on throw distance Wherever possible front fill systems should be physically located close to subwoofers in order to provide closest members of the audience with some mid high information to help offset the exaggerated LF contour when located directly in front of the subwoofer stacks Distributed dV DOSC front fill integrated with distributed ground stacked subwoofers ARCS stereo infill integrated with ground stacked split centre subwoofer position ARCS stereo infill plus offstage fill Distributed 112 front fill Figure 84 Stereo infill and distributed front fill options L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 105 of 158 3 6 2 OFFSTAGE FILL Good candidates for offstage fill include dV DOSC ARCS KUDO or additional V DOSC arrays Selection between these option
125. ariation of vertical coverage angle with frequency 152 Figure 14 Anele strap calibration REG aue edu NEAR ERE Ne 154 LIST OF TABLES Table L ACOUSTICS LA48a power amplifier ratings 38 Table 2 Load and Power Ratings Tor V DOSG Loses 39 Table 3 PADO4a COMB Wiring Chart Leere eee ennt nnnnn enne esses ttt 41 Table 4 PADO4a Internal Amp Rack Wiring 16 66 000000000 41 Table PADO23 COMB Wirnine Chart E 42 Table 6 PADO2a Internal Amp 25 42 Table 7 V DOSC preset DSP output channel assignment and COMB connector summary 45 Table 8 2 way 3 way stereo preset DSP output channel assignment and COMB connector summary 47 Table 9 SUB LOW OPERATING BANDWIDTH SUMMARY 52 Table 10 Recommended Limiter Threshold Settings 58 Table IIS Presets cece 59 Table 12 2 T A DP226 PEeSBES orei a ees 60 bake Contour cA 61 Table 14 BSS 05 366 id too a
126. asons Tight ratcheting can increase the angle between flown enclosures up to an additional degree i e a 4 degree angle strap can produce 5 degrees etc This increase in angle can be non constant vertically along the array and is difficult to predict or control typically the bottom enclosures are affected first 5 5 degree angle strap be modified to 6 5 degree value with tight ratcheting and WST criteria will not be satisfied When ratchet straps are overtightened and the array is excessively tilted upwards physical damage can result to the flytrack and or angle strap fittings L ACOUSTICS has developed a spacer block to eliminate the need for use of ratchet straps specifically for the case of arrays with upwards tilt Moderately ratcheting flown arrays IS recommended for the following reasons Ratchet straps introduce a continuously variable tweak factor that allows for fine tuning of coverage down front and greater angle strap resolution when used correctly in conjunction with top and bottom inclinometers When the array is pointing downwards the centre of gravity shifts backwards and the top V DOSC enclosures tend to close naturally forming a flat long throw section this is desirable for flat audience open air festival situations For larger 12 16 enclosure arrays even though 0 75 degree angle straps are used for the first 6 8 enclosures the actual obtained angles will L ACOUSTICS V DOSC
127. atch the rms power handling for individual sections according to the tables below Table 10 Recommended Limiter Threshold Settings LIMITER THRESHOLDS CALIBRATED TO RECOMMENDED POWER AMPLIFICATION 2 x RMS Power Handling for Sub Low Mid and 4 x RMS Peak TONG Handling for Hi MODEL ohms volts 32 dB gain SETTING SB218 V DOSC LO V DOSC MID V DOSC HI AMP CLIP IS AT 9 5 dBu SB218 V DOSC LO V DOSC MID V DOSC HI NOTE The LA48 has a comparatively low input sensitivity 9 5 dBu and in practice it can be necessary to equally scale up the individual crossover channel output gains in order to have sufficient drive capability note this has been done for Version 7 preset library release It is far better to use the output drive capability of the DSP digital to analog converters DACs and analog output section rather than overdrive the input analog to digital converters ADCs so do not be afraid to increase the channel output gains uniformly in order to achieve a comfortable gain structure Whether this is necessary will also depend on how hot or cold the FOH mix engineer likes to run his console When in doubt disconnect all loudspeaker cables and run pink noise from the console at nominal level through the crossover to the power amplifiers and examine crossover input output levels crossover limiter indicators and amplifier clip indicators to verify system protection and gain structure L ACOUSTICS V DOSC Manual Vers
128. atively under dark conditions indoors a small flashlight can be attached at the junction between the top and second enclosures The final trim angle adjustment is checked from the rearmost seats of the audience when the light can be seen through the gap separating the first and the second enclosures the angle of the array is correct Under daylight conditions outdoors the trim angle can be visually checked from the rearmost audience section flashlight not required If the gap between the top and second enclosures is clearly visible then the focus is correct Note Bushnell Rangefinder glasses can be useful for checking gaps between cabinets at long distances Coverage up close can be visually verified to ensure that the top wall of the bottom enclosure is in line with the desired aiming angle for the closest members of the audience For final angle adjustments a pair of radios is useful while one person walks the venue and visually inspects the array while a second person operates the site angle adjustment motor front motor for ARRAY2004 rear motor for SOUNDVISION For all of the above alternatives several pieces of string or light rope can be run from the floor over the BUMP2 and to the Maglite laser device or remote inclinometer in order to pull the instrument free and lower it after measurements have been performed If a DELTA PLATE is used on or off stage rotation of the entire array can also be adjusted Three motors are used in
129. bar for rigging up to eight SB218 enclosures deep in a vertical line array 17 dV BUMP2 Flying bumper for rigging up to six dV SUB enclosures deep in a vertical line array also an alternative to dV BUMP for rigging dV DOSC and or dV SUB Figure 12 Subwoofer Rigging Accessories L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 26 of 158 AMPLIFICATION 18 L ACOUSTICS LA48a Compact light weight two channel power amplifier 2 rack units 10 kg 1300 watts per channel into 8 ohms 2300 watts per channel into 4 ohms C olan Power Amplifier LA 48a Figure 13 LLACOUSTICS LA48a Power Amplifier Note for full details see the LA48a user manual available for download on www l acoustics com AMPLIFIER RACKS 19 20 21 22 23 24 25 RKI2U 12 rack unit amplifier rack empty Light weight aluminum space frame construction internal shock mounting standard rack rails provision for rear support of amplifiers transparent lexan doors that store inside the rack high impact resistance polyethylene cover no external case required Recessed Aeroquip flytrack sections for flown applications RKI22a RKI2U supplied with PADO2a PADOSEC 2U drawer 2U blank panel rear support kit for 2 L ACOUSTICS LA48a power amplifiers LA48a power amplifiers not included RKI24a RKI2U supplied with PADO4a PADOSEC rear support kit for 4 L ACOUSTICS LA48a power amplifiers LA48a power a
130. by using the 58218 DELAY ARC 80 Hz 58218 LCR 80 Hz presets subs with negative polarity X PRESET Align 582 8 dipl peak 2 with V DOSC low section File C SMLSSHSTU7ZSTIMERLSXNSUBLOM FRQ 8 27 2883 6 5 File C HLS HSTU7 TIHERL X LUM TIN 27 2883 6 58 PH Impulse Response volts Transfer Function Mag dB volts volts 8 38 oct gt uur z Zee z 20 0 100 0 1000 0 log Frequency Hz 20 0 40 0 50 0 Tine msec Figure 39 X preset time alignment procedure X AUX PRESET The X AUX preset extends the V DOSC low section down to 30 Hz while ground stacked SB218s are run from 25 80 Hz with negative polarity to account for the phase shift due to the overlap in operating bandwidths 58218 25 80 Hz with negative polarity V DOSC low 30 200 Hz The X AUX preset takes full advantage of V DOSC low section resources and can be implemented using Input B Output 6 for the standard X preset Note for 4 2 configurations V DOSC ARCS or dV DOSC separate X AUX presets are provided for and LAKE digital signal processors to allow for aux sub drive The X AUX preset is intended for applications where SB218 subwoofers are ground stacked and physically separate from the flown V DOSC AUX SUB drive can also be implemented using the SB218 DELAY ARC 80 Hz or SB218 LCR 80 Hz presets subs with negative polarity X AUX PRESET Align SB218 peakl dip2 with V DOSC low section 58218 polarity Transfer Function hag
131. chieve this goal The first step is to minimize the distance between sound sources By doing this for a given frequency we have a better chance of maximizing the number of sources within the first constructive ring This situation is more likely to be achieved on the main axis perpendicular to the line array as shown in Figure 106 Note that in Figure 106 the source separation is smaller than in Figure 105 so that more sources lie within the first constructive ring Moving away from the main axis as in Figure 107 the number of sources within the first constructive ring decreases progessively until there are equal numbers of constructive and destructive sources and they cancel each other outside of the coverage region Clear separation between coherent and incoherent wave fields defines the consistency of the main coverage region n coherent wavefield defines the beamwidth Figure 106 Constructive interference rings for a condensed point source line array at observation point M L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 146 of 158 m lt incoherent wavefield wavefield illustrating es rajaction out of beamwidth Figure 107 Destructive interference rings out of beamwidth for two kinds of line arrays condensed and standard
132. chnique for processing a central ground stacked horizontal line array of subwoofers is to use delay processing to electronically arc the subwoofer array Two presets are provided with 60 Hz 58218 INFRA mode and 80 Hz 58218 4W or X AUX mode crossover points Another useful technique is to create a Left Centre Right LCR array of subwoofers where each block has the same number of subwoofers For the case of the LCR sub array L R arrays can be oriented at 45 degrees offstage and instead of a single buildup between L R arrays as for L R split stacks with an LCR array there are two mini buildups between and C R that help to smooth out the centre build up that is obtained with configurations Two presets are provided with 60 Hz 58218 INFRA mode and 80 Hz 58218 4W or X AUX mode crossover points and channel assignments that are suitable for implementing LCR sub arrays L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 54 of 158 INFRA PRESET The INFRA preset features a 60 Hz crossover between 58218 subwoofers and the V DOSC low section Main benefits obtained using the INFRA preset include improved low frequency impact from the flown V DOSC array simplified time alignment since wavelengths are longer and possible subjective preference for the subwoofers when run from 60 Hz on down since they become more of a delocalized effect In addition power resource simulations have shown that the INFRA preset provides an excellent r
133. constant curvature array of 8 V DOSC with 4 between all enclosures provides constant 28 vertical coverage above F 794 Hz with narrower coverage at F 427 Hz and with a broadening of coverage below F 230 Hz that is subject to the laws of diffraction govern ing spherical wave propagation degrees nominal coverage F frequency Figure 113 Illustration of the variation of vertical coverage angle with frequency L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 152 of 158 APPENDIX 7 WST Criteria Number 5 In the AES Journal paper Wavefront Sculpture Technology Vol 51 No 10 October 2003 it is shown that the maximum angle allowed between enclosures is given by the following expression 1 STEP 180 C uk E 2AARF STEP d s e According to WST Condition the Active Radiating Factor ARF should be higher than 80 The STEP distance is the separation between acoustic centres and dmn is the minimum distance to the closest members of the audience For front loaded systems such as V DOSC or dV DOSC it is basically the size of the component that determines the vertical height of the enclosure and in turn the separation between acoustic centres Taking the nominal component diameters for 8 12 15 and 18 speakers and adding two thicknesses of wood for the top and bottom enclosure walls therefore determines the STEP distances given in the table below ARF is set to 8096 since this is the limit for satisfying WST C
134. d drive subs with the same signal 4 way mode All presets 4W INFRA X X AUX will function with aux sub drive or in 4 way mode however the user should be aware of the operating bandwidths and select the preset that is most appropriate for the installed configuration and application Please refer to Table 9 for a summary of sub low preset processing and the following for a discussion of preset selection issues Subwoofers as a Low Frequency Extension In this case subwoofers are driven in 4 way mode with the same signal that is sent to the V DOSC array All 4 2 presets are optimized for this type of system drive input outputs 1 2 3 4 58218 V DOSC LOW MID HIGH respectively and the same channel assignments apply to 5 1 format presets when the system is operated in 4 way mode Subwoofers as an Effect In this case subwoofers are driven using a separate aux send that is different from the signal sent to the V DOSC array All 5 format presets allow for aux sub drive using input output 6 Note Additional 5 presets are provided for Lake Contour and 226 that allow for driving 2 way enclosures ARCS and dV DOSC in conjunction with V DOSC and aux sub drive For these presets channel assignments are different Input A outputs 1 5 V DOSC LOW MID dV DOSC LOW dV DOSC HI respectively and input B output 6 58218 This type of preset is not required for BSS 366 since the input source for the 58218 can be
135. d offstage fill system options 106 Figure 87 SOUNDVISION simulation for a LL L R RR V DOSC FOH system with 4 delay positions 107 Figure 88 Flown and stacked delay systems 108 Figure 89 Stacked dV DOSC delay System 108 Figure 90 Flown V DOSC delay 5 5 108 Figure 91 Stacked V DOSC offstage fill 00000000000000000000000000000000005 4 Figure 92 SOUNDVISION mechanical 4 112 Figure 93 SOUNDVISION installation report 13 Figure 94 ARRAY 2004 installation data 13 Figure 95 Photo sequence showing the steps involved in flying V DOSC 119 Figure 96 Recommended Installation Tools 131 Figure 27 V DOSC Enclosure Linie Drawing onere eere Hn aeneus Poser Fade uae labes aue uas Pre eo dedu 133 Figure 98 58218 Subwoofer Line 134 Figure 99 V DOSC Flying Bumper Line 2 0010000000000000000000000000000000004 135 Figure 100 58218 Flying Bar Line
136. d to double check the system installation angle strap selection ratchet strap tensioning system focus and whether FOH L R arrays are correctly matched In addition a common problem with FOH engineers who are unfamiliar with V DOSC is the tendency to over equalize the mid section since they are unaccustomed to the nearfield listening experience over this frequency bandwidth The CVE or QVT accompanying the V DOSC system should attempt to dissuade over equalization and educate the guest engineer whenever possible A better solution is not to equalize the mid band but to simply reduce the level of vocals etc in the mix Several strategically placed parametric notches can be highly effective in compensating for room reverberation modes and for better resolution it is recommended that the parametric filters available on the inputs of the digital signal processor are used for system eq In a festival situation an effective approach is to perform system equalization using the input parametric filters then turn the system over to the guest FOH engineer with house graphic eqs set flat Typically guest engineers are more comfortable with a graphic eq for quick adjustments on the fly and after each act the graphic can be reset for the next engineer System predelay is commonly used to improve the combined integration of the main FOH system with the sound coming from onstage In some cases alignment with the instrument backline guitar amplifier stacks kic
137. dling is 2 x 375 Wrms 600 Wrms and 200 Wrms for low midrange and high sections respectively Low frequency transducers are powered individually at a nominal 8 ohm impedance midrange frequency transducers are connected series parallel for overall nominal 8 ohm impedance and high frequency transducers are connected in series with a nominal 16 impedance All components weather resistant and connection to the loudspeaker is made via two parallel 8 pin connectors Although V DOSC is a 3 way design the enclosure is powered by 4 amplifier channels Enclosures are connected to amplifier racks using V CABLEs 7 m or 25 m length as required that are equipped with 8 pin Cannon CA COM connectors of the bayonet locking type Each V DOSC enclosure is L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 33 of 158 provided with two connector sockets for direct connection and for paralleling of up to three enclosures using DO 7 V CABLEs The rectangular shape of the enclosure allows for easy stacking transport and handling A front mounted dolly board is provided for protection and transportation Stacking runners located on the bottom of the cabinet act as skid pads to protect the cabinet finish and mate with stacking runner recesses the top of the enclosure for enhanced stability when stacking Cabinet dimensions are 30 cm 51 2 wide 43 4 cm 17 1 high 56 5 cm 22 2 in deep and were designed to allow for efficien
138. dspeakers the goal is to align the filled circles in order to have even coverage Note V DOSC geometric data is different in SOUNDVISION versus ARRAY 2004 In order to have consistent coordinate references for all L ACOUSTICS products the convention adopted for SOUNDVISION is that 0 and bumper elevation coordinates are referenced to the front of the top V DOSC and site angles are referenced to the centre of each enclosure Please see figure 51 for details For dV DOSC figure 49 still applies Mapping mode provides a color coded representation of the SPL distribution over the defined room geometry and allows for visualization of the coverage of individual loudspeakers as well as the interference between multiple loudspeakers In mapping mode the user can select individual 1 3 octave bandwidths unweighted or A weighted SPL or any frequency range between 100 10k Hz Typically the 1 10 kHz bandwidth SPL mapping is considered to provide a good representation of system performance since this frequency bandwidth is primarily responsible for perceived system intelligibility and clarity To illustrate the V DOSC coverage Figure 52 shows SPL mappings at octave band frequencies for an array of 12 V DOSC enclosures angles top to bottom 4 4 4 4 4 4 4 4 4 4 3 For this example the V DOSC array is perpendicular to a target plan having dimensions of 35 x 100 metres at 30 metre throw distance imagine the V DOSC array firing at a large wall Cover
139. ductors or performers and the audience In order to obtain nominally flat response for speech or classical music sound reinforcement mid high ratios will have to be scaled up by approximately 6 8 dB and or the low sub output gains attenuated depending on the size of the array At the opposite end of the spectrum for heavy metal shows sub low contours below 100 Hz tend to be 30 dB higher than the nominal mid high response Due to it s coplanar symmetric design V DOSC has very stable frequency response throughout it s coverage region and equalization adjustments made at the mix position translate well throughout the audience When properly installed and focussed room related effects above 300 Hz are minimized and consistent system performance from venue to venue effectively allows V DOSC to serve as an accurate reference monitor for the FOH engineer At lower frequencies array coupling and room related effects will typically require equalization in the 20 300 Hz range and it is important to walk the room and or perform spatial averaging measurements to ensure that system equalization adjustments are valid throughout the coverage region of a given array Due to system phase coherency small equalization adjustments are highly audible i e you can hear the system respond to eq as well as to adjustments on the mixing console If you find that it is necessary to apply excessive amounts of equalization to the system above 300 Hz it is advise
140. e locked in place Attach the rear chain motor to the rear BUMP2 fly point using a shackle See Fig 95 p Do not connect the front chain motor yet this can be done once the first few cabinets are flown Note For added safety factor when flying large arrays bridling should be employed For bridling 2 steel slings are attached to the outer points on the bumper using shackles then joined using a pear ring for attachment to the motor requires 2 steel slings 4 shackles pear ring per point With three people available one person runs the chain motors while the other two attach angle straps and insert spacer blocks as the array is lifted Stagehands can be assigned the tasks of steadying the array from behind providing necessary cable slack and removing stacking dolly boards L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 114 of 158 With one person on either side of the array raise the rear chain motor Enclosures of the array will bend automatically since they are connected by the rear pivoting legs and dolly boards automatically detach as the cabinets lift off see Fig 95 q When the first enclosure leaves the ground stop raising the array Lower the front motor and connect the front rigging point the BUMP2 to the chain motor see Fig 95 Note 1 3 ft steel extension stinger is required for the front downstage motor attachment point in order to prevent the motor chain bag from hanging down in front of the
141. e the measurement gear required to measure impulse responses If you have the ability to measure impulse response refer to the following figures for individual presets as a reference for time alignment Basically when you look at the separate impulse responses for sub and low sections there is a sine wave signature that needs to be aligned SUB LOW GAIN SCALING PROCEDURES The Version 7 preset release has been optimized for a 1 5 cabinet ratio of V DOSC 58218 for example 3 2 6 4 9 6 12 8 15 10 As a starting point output channel gains for a 3 2 V DOSC SB218 cabinet ratio are as follows Hl presets WWIMERT X INFRA aw mm 2 8 2dB MID 5 dB 5 dB 5 dB 5 dB Recommended gain scaling procedures for different cabinet ratios are summarized as follows 2 1 V DOSC SB218 ratio scale subwoofer gain by 2 dB or low section by 2 dB 5 1 V DOSC SB218 ratio standard gains 5 2 18 ratio scale low gain by 4 dB Following this gain scaling procedure according to cabinet ratio will provide a consistent sub low spectral contour for all 4 way presets The mid and high sections should then be scaled up or down equally according to the size of the array in order to compensate for low frequency coupling effects and to provide the overall desired tonal balance see also Chapter 5 re tuning SUBWOOFER PRESETS DELAY ARC LCR For large format configurations a useful te
142. eakon connectors 3 m length for use with DO7 DO25 cables PADO2a or PADO4a and 3W A 3W B COMB connectors for powering 2 way enclosures plus subwoofers DO2W CA COM 8 pin male barrel plus coupling ring to 2x NL4 Speakon connectors 3 m length for use with PADO2a or PADO4a 2 WAY 2W A 2W B 2W STEREO COMB connectors for powering 2 way enclosures DO3W CA COM 8 pin male barrel plus coupling ring to 3x NL4 Speakon connectors 3 m length for use with PADO2a or PADO4a and 3W A 3W B COMB connectors for powering 2 way enclosures plus subwoofers CC4FP Female female 4 conductor Speakon barrel adapter L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 31 of 158 DO 7 V DOSC LINK CABLE e DO25 V CABLE DOSUB CABLE DOIOP EXTENSION SP 7 DOFILL DO3WFILL DO3W CC4FP Figure 16 Loudspeaker cabling options L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 32 of 158 1 2 V DOSC SPECIFICATIONS STACKING RUNNER RECESS Dimension WxHxD 1300mm x 434mm x 565mm 51 2 x 17 1 x 22 2 Weight 108 kg 238 Ibs 9 5 kg 21 Ibs with dolly FLYTRACK EE mr Hi KIN M e 9 m C AXE FIXE U PIN ROTATING LEG BALANCIER Figure 17 V DOSC Enclosure Front and Rear Views V DOSC is an active full range 3 way loudspeaker enclosure that satisfies WST conditions when vertically arrayed Each V DOSC enclosure contains two direct r
143. eatable at high frequencies L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 126 of 158 Step By Step Tuning Procedure In general terms installation and tuning proceeds as follows Room Dimensions gt ARRAY or SOUNDVISION Sound Design Installation Parameters System Install System Focus Preset Selection FOH Drive Rack CO24 Channel Assignment Configure Amp Racks System Check Coverage Check Time Align Balance Tune With reference to the installation parameters calculated in ARRAY or SOUNDVISION install the system and perform trim and site angle adjustments according to the procedures outlined in Section 4 2 2 Configure your signal distribution system by selecting the appropriate preset for your configuration and refer to the Preset Setup sheets tables 11 14 while patching your signal distribution system Configure COMB connectors for all amplifiers racks accordingly and remember the old saying amps on last amps off first 3 Send pink noise to each array one array at a time band by band and spin up amplifier channels individually and sequentially in pairs For all bands turn up amp channel to make sure it s working and then amp channel 2 to confirm that there is acoustic summation with channel Then turn down amp channel to confirm that 2 is working Then turn up amp channel 3 to check acoustic summation with channel 2 etc Repeat the process i e and 2 2 2and 3 3 3 and
144. ect to the vertical cutview geometry of the audience in accordance with WST Condition 4 In the horizontal plane the displayed isocontours ARRAY 2004 or impact coverage SOUNDVISION should overlap to a certain extent and cover the majority of the audience For the amount of overlap see below for a discussion of the tradeoffs between stereo perception versus intelligibility The remaining uncovered areas should be covered with fill speakers such as dV DOSC ARCS KUDO additional V DOSC arrays Additional distributed front fill or stereo infill systems using L ACOUSTICS MTDI08a MTDII2b MTDII5b II2XT II5XT or 115 loudspeakers are also highly effective in complementing V DOSC system coverage 3 2 1 THE LEFT RIGHT CONFIGURATION Although not the best technical solution the left right configuration meets both visual and practical criteria and is most commonly used V DOSC is a dramatic improvement over conventional systems but by nature the stereo imaging of any left right system is limited for a large part of the audience and there are compromises with respect to the consistency of tonal balance in the horizontal plane The biggest problem for any left right system is non uniformity of tonal balance horizontally Typically an excess of low frequency energy builds up in the middle accompanied by reduced intelligibility The net result is that the system sounds bass heavy or thick in the middle harsher or more aggressive when d
145. efore to simulate stacked system coverage users should enter 1 75 2 3 3 0 4 0 5 0 do not use instead of 0 75 1 3 2 0 3 0 4 0 5 5 Output Data In the columns adjacent to where angle strap values are entered the site angles i e what you would measure if you put a digital inclinometer on each enclosure and the wavepath throw distance for each enclosure are tabulated Note The site angle for enclosure is essentially equal to the V DOSC bumper site angle since the first enclosure is attached to the BUMP2 with minimum separation within physical tolerance limits using the BUMP angle strap When the system is pointing down negative site angle for 1 the top enclosure will close against the bumper normally this is indicated by a negative 2 Angle Stress value in MECHANICAL DATA cells When pointing upwards there will be a small gap between the top V DOSC enclosure and the bumper and therefore a difference between site angle 1 and the 2 site angle For this reason always attach a laser and or remote digital inclinometer to the top of V DOSC enclosure 1 not the V DOSC bumper in order to accurately measure the true focus of the top enclosure Also tabulated are continuous A weighted SPL estimates throughout the coverage of the array on an enclosure by enclosure basis These dBA estimates are derived using a Fresnel type calculation see Appendix 2 using a 2 kHz reference frequency for a 4 dBu nominal input sign
146. em with the central line array of subwoofers can help offset this increased amount of low frequency energy behind the central line array which can cause feedback problems on stage Unless electronic delay processing is applied the horizontal directivity will narrow the extent of narrowing depends on the length of the central line array Potential for reduced throw due to audience absorption this problem is likely to occur with any ground stacked configuration A good technique for controlling the directivity of a central ground stacked horizontal line array is to use delay processing to electronically arc the array Electronic delay processing in this manner will decouple sections of the array so that tonal balance is improved up close while at the same time low frequency coverage is smoother throughout the audience in the horizontal plane The optimum arc radius is typically equal to half the length of the central line array delay taps are calculated geometrically based on this arc radius and the physical distance to the centre of a given subwoofer group off the center line reference a Horizontal line array b Delay processed horizontal line array Figure 76 Centre subwoofer line array a without and b with electronic delay processing To implement electronic delay processing a 4 or 6 channel DSP is dedicated to subwoofer drive and the 58218 DELAY ARC 80 Hz preset subs with negative polarity used in conjunction with
147. enclosure site angle impact spacing for an 8 enclosure variable curvature V DOSC array interenclosure angles 0 75 0 75 0 75 1 3 2 3 5 degrees NON CONSTANT SPACING CONSTANT SPACING 4 72 6 dB attenuation per 3 dB attenuation per distance doubling distance doubling Figure 47 c Plan view representation of non constant a versus constant spacing b arrays L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 69 of 158 Typically optimum coverage is obtained iteratively by varying the height of the array and the enclosure angles 1 to next 2 to next etc The designer manually performs the optimization by visually referring to the spacing between impacts after making changes to the array Once equal spacing has been achieved the designer has successfully optimized the performance of the system by shaping the array s vertical isocontour to match the audience geometry Angle strap values bottom enclosure elevation site angles for top and bottom enclosures and trim height parameters are then recorded and used for installation of the system see Output Data Note There is a difference between nominal angles for flown versus stacked arrays When V DOSC enclosures are stacked the rear corners of cabinets are touching due to gravity and when flown there is a small gap This difference approx cm over the depth of the cabinet corresponds to an additional degree for stacked versus flown systems Ther
148. end of a tape measure can be attached using some duct tape The tape measure is used to raise the array to the proper height based on the geometrical data which was pre calculated using ARRAY2004 or SOUNDVISION see above and can be pulled loose afterwards Under dark conditions indoors a laser pointer or laser level can be attached to the top of the upper V DOSC enclosure Trim angle adjustments are then given by the focus of the laser on the audience no walking to the back of the venue is required although laser glasses or a set of binoculars can be useful in locating the laser beam Coverage up close can be checked by attaching the laser device to the lower wall of the bottom enclosure or visually looking for the bottom wall of the bottom V DOSC enclosure to see where coverage starts As described above mounting a remote digital inclinometer on the top enclosure and using handheld digital inclinometer is very useful for tensioning ratchet straps and verifying that the overall vertical coverage angle of the array matches what was simulated in ARRAY 2004 Once the system is flown to trim the tilt of the array can be set using the remote inclinometer and setting the tilt Site Angle 1 1 5 degrees in Figs 93 and 94 It is important to perform this final adjustment once the array is at the correct trim height since chain motors typically do not run at exactly the same speed if the front and rear load distribution is different Altern
149. ent Figure 65 LCR Configurations L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 89 of 158 3 3 MULTIPLE ARRAY CONCEPTS When the horizontal coverage of a V DOSC array 90 nominal 70 effective is insufficient it is not recommended to place a second array directly beside the first one see Appendix for further details The correct approach is to utilize a second array which is focused on another portion of the audience typically at 45 70 relative to the first array and spaced at least 6 7 meters approximately 20 ft from the first array 2 5 2 5 m 4 20 30 gt 4 1 05 1 05 gt 4 20k 6 7m 40 70 x M 2 40 70 WRT MAIN M WRT MAIN A 05 7199 Figure 66 Generic rigging plot for V DOSC system consisting of main and LL RR offstage fill arrays Given this separation interference only occurs in the low frequency range and there are no audible intelligibility losses for the following reasons the first octave wide comb filtering cancellation is shifted lower in frequency outside the V DOSC low section s operating bandwidth for example 24 Hz for two arrays of the same size spaced 7 metres 2 low frequency cancellations from 50 200 Hz tend to be masked or filled in by room reverberation and 3 the ear cannot resolve tightly spaced comb filtering notches at higher frequencies throughout the overlap region of the tw
150. epartition of resources between sub low and high sections INFRA preset is intended for ground stacked subwoofer flown V DOSC configurations physically separated AUX SUB drive can be implemented using Input B Output 6 or by using 58218 DELAY ARC 60 Hz 58218 LCR 60 Hz presets subs with positive polarity INFRA PRESET Align SB218 peak I dipl peak 2 with V DOSC low section File C HLS HSTU T TIHERL IHFRA SUBL PEK3 FRO 8 27 2883 5 48 Fila C HLS HSTU TIHERL IMFREY LOH 27 2003 5 29 PH Transfer Function Magy dB 08 38 oct Inpulse Response volts mu or oh bo 20 0 100 0 1000 0 30 0 40 0 _ 50 0 log Frequency Hz Tine msec Figure 37 Infra preset time alignment procedure 4W PRESET The 4W preset features an 80 Hz crossover between 58218 subwoofers and the V DOSC low section 4W presets provide a flatter overall response contour that is considered more suitable for classical music or speech reinforcement Although the 80 Hz HPF for the V DOSC low section does not fully utilize V DOSC low end resources subjectively the low end can sound tighter due to the 80 Hz crossover point but this is a matter of personal taste and program material Venue acoustics can also be a factor in selecting between INFRA and 4W presets in difficult reverberant rooms experimentation between these two presets is suggested The 4W preset is intended for ground stacked subwoofer flown V DOSC
151. erage and require additional fill systems see Multiple Arrays It is also common to have two sections of the audience area that have different slopes for example the transition between floor level and the tribune in arenas In this case coverage of the areas at the transition between the two slopes should be examined carefully and angles selected accordingly Finally to effectively complete any V DOSC installation stacked or flown during the actual installation it is important to verify that the parameters calculated in ARRAY 2004 or SOUNDVISION have been implemented correctly Tools that are useful for this purpose are described in Chapter 6 4 Detailed flying and system focussing procedures are described in Section 4 2 BAD 2 6000 74 2 UN i Pir 974 a _ Figure 63 Flown V DOSC System Coldplay World Tour 2001 2002 sound design T Smith L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 87 of 158 3 2 ACHIEVING OPTIMUM COVERAGE ARRAY 2004 or SOUNDVISION are convenient simulation tools for optimizing the coverage for a complete system consisting of multiple V DOSC arrays and complementary fill systems Parameters for each array such as spatial coordinates azimuth angle i e horizontal panning number of enclosures and inter enclosure angles are entered by the sound designer and individual elements of the sound design are optimized with resp
152. es and 2 pear rings L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 34 of 158 A unique feature of the V DOSC rigging system is the fact that the relative action of the front and rear chain motors can be used to adjust the vertical site angle of the entire array The rear rotating legs of the entire assembly provide the mechanical connection and bear the majority of the load while the angle straps determine the angle between adjacent V DOSC enclosures As the array is tilted upwards the overall centre of gravity shifts forwards and the load distribution progressively shifts from the rear rotating legs to the angle straps As a result the maximum upward tilt angle is approximately 5 degrees NOTE Exact mechanical load conditions depend on the size shape and site angle of the array Always refer to the mechanical data provided in ARRAY or SOUNDVISION software to verify that safe rigging conditions apply with respect to load distribution NOTE A single 2 can safely fly an array of up to 16 V DOSC enclosures 15 V DOSC 3 dV DOSC or 14 V DOSC 6 dV DOSC Recommended chain motor ratings for each rigging point are as follows 0 5T motor per point for a 4 enclosure array motor per point for 5 to 10 array 2 0T motor point for an Il to 16 enclosure array BUMP2 can also be used for stacking V DOSC In this case the BUMP2 is inverted upside down the first enclosure of the array is stacked
153. estructively tested to validate the final design using a pulling bench equipped with laboratory calibrated measuring cells L ACOUSTICS hereby declares that the above product conforms to The Machinery Directive 98 37 CE Part 4 Lifting Accessories 2 Low Voltage Directive 73 23 CE harmonized standard EM60065 Established at Marcoussis France on the 13 of August 2003 Signature of L ACOUSTICS representative Jacques Spillmann Chief Engineer Manufacturing 155 158 DECLARATION OF CE CONFORMITY For the product Catalog Item BUMP2 Description Rigging structure for L ACOLISTICS v DOSC loudspeaker Dimensions 1300 mm x 100mm x 140mm x D x Material Steel Supplied with the following accessories x Steel Sling Length meter WLL IT ELIT 3 Shackle Diameter 22 mm WLL 2T 22 2x MC DOAXE 2 x Ratchet Strap CA SANGLE 2 x Angle Strap BUMP23 4 x Stacking Screw jacks DOPIED Optional accessories ANGLE STRAPS BUMPER 0 75 1 37 27 3 4 Product Origin Country of origin the product France Country of origin for components of the product EEC Technical 5 The BUMP2 rigging structure allows for suspension of up to 16 V DOSC loudspeaker when used in the following conditions 2 rigging boints rear and front BUMP tilt angle ranging from 10 to 10 Any angle value between adjacent loudspeakers
154. etails As pictured in Figure 4 cylindrical wave propagation results in a 3 dB reduction in SPL with doubling of distance as opposed to the 6 dB reduction that is typical of conventional systems that radiate spherical wavefronts Line source Cylindrical Wave Expands in horizontal dimension only At 2R surface area increases 2 times 3 dB attenuation Point source Spherical Wave Expands horizontally and vertically At 2R surface area increases 4 times 6 dB attenuation Figure 4 Cylindrical versus spherical wave propagation Due to it s ability to generate cylindrical wavefronts V DOSC has different attenuation properties than conventional systems and should not be evaluated in terms of the classical kilowatt ratio Comparing SPL predictions according to standard calculations is also not meaningful since V DOSC produces a combination of cylindrical and spherical wavefront propagation that must be evaluated using specific calculations Aside Conventional modeling techniques cannot accurately simulate WST based systems such as ARCS KUDO dV DOSC or V DOSC For WST based products L ACOUSTICS has worked with the developers of EASE and CATT to integrate proprietary SOUNDVISION modeling techniques into these industry standard room acoustics modeling programs When curved V DOSC arrays are employed there is a combination of cylindrical and spherical propagation This combined propagation together with the
155. exceptional stereo imaging properties that are characteristic of V DOSC Other practical benefits of the coplanar symmetric configuration include the fact that there is no need to fly mirror imaged L R arrays plus rigging issues are further simplified since the enclosure s centre of gravity is also symmetric Figure 3 Coplanar Symmetry of V DOSC Distributed sound reinforcement using coaxial loudspeaker technology L ACOUSTICS other approach to sound reinforcement Either we respect WST criteria to obtain coherent coupling between individual sources and create a single coherent line source as for V DOSC dV DOSC KUDO ARCS or we separate individual coherent sources MTD or XT coaxial loudspeakers in a manner so that desired audience coverage is achieved while the effects of audible interference are reduced For more details on the benefits of coaxial loudspeaker technology and distributed sound design techniques please refer to the MTD or XT User Manuals available for download on www l acoustics com L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 15 of 158 Apart from coverage precision and predictability another significant benefit of V DOSC is the fact that the system effectively extends the nearfield region at higher frequencies the nearfield is defined as the region where cylindrical wavefront propagation applies and the farfield is the region where spherical wavefront propagation occurs see Appendix 5 for further d
156. f the audience has grown inevitably leading to an increase in the number of loudspeakers In the past conventional horn loaded trapezoidal loudspeakers were typically assembled in fan shaped arrays according to the nominal horizontal coverage angle of each enclosure in an attempt to reduce coverage overlap that causes chaotic interference With this type of arrangement the optimum clarity available in one direction could only be provided by the individual enclosure facing in this direction Attempts at flattening the array to achieve greater throw and higher SPLs resulted in severe interference in an uncontrolled way affecting coverage pattern control intelligibility and overall sound quality Even when arrayed according to specification always an optimum compromise since the polar response of individual horns varies with frequency the sound waves radiated by individual horn loaded loudspeakers do not couple coherently thus the conventional system approach is fundamentally flawed see Appendix Furthermore the chaotic sound fields created by interfering sound sources waste acoustic energy thus requiring more power than a single coherent source would in order to obtain the same SPL As an illustration of this imagine throwing some pebbles into a pool of water If one pebble is thrown into the water a circular wave will expand concentrically from the point where it entered If a handful of pebbles are thrown into the water we observe t
157. f the bumper and the autofocus adjust angle Normally ARRAY 2004 automatically focuses the top V DOSC enclosure to the rear of the audience geometry defined in Cutview Autofocus adjust can be used to adjust the overall focus of the array and DOES NOT CORRESPOND TO THE TILT ANGLE OF THE V DOSC BUMPER For safety reasons the maximum upward tilt angle for the array given by Site 1 to next is approximately 5 degrees Results of detailed mechanical load calculations are displayed in the MECHANICAL DATA cells in ARRAY 2004 software to determine exact array tilt angle limits NOTE Always refer to the MECHANICAL DATA cells in ARRAY 2004 to verify that safe rigging conditions apply with respect to load distribution The designer then chooses the angular spacing between enclosures from the available values in the pull down menu 0 75 1 37 2 3 4 5 57 The red lines show the aiming directions of all enclosures where each line is aligned with the bottom of its respective enclosure Note that the displayed top block corresponds to the V DOSC bumper not the first enclosure of the V DOSC array dV DOSC downfill or upfill enclosures can be conveniently simulated in V ARRAY2 sheets using the available cells Note For dV DOSC downfill simulation autofocus adjust angle 0 degrees corresponds to the first dV DOSC enclosure as tightly wrapped to the bottom V DOSC i e a relative site angle of 3 75 degrees For dV
158. f the isocontour can then be used to predict the effective coverage of a V DOSC array in the horizontal plane By overlaying or projecting the isocontour on a plan view of the venue the sound designer can adjust the azimuth angle or panning of each array to get the best coverage results for a given audience layout Other sound design issues that can be examined using the isocontour include optimizing stereo imaging represented by the amount of overlap between FOH L R isocontours front fill stereo infill or offstage fill requirements avoiding wall reflections As seen in Figure 43a at lower frequencies the isocontour becomes more omnidirectional although there is still pattern control maintained in the forward direction and approximately 20 dB of SPL rejection behind the array For simulation purposes horizontal isocontour data is provided in the H ISOCONT sheet in ARRAY 2004 For further details on how to use this data in sound design please see Section 2 3 Figure 43a Horizontal V DOSC isocontour averaged from 630 Hz 16 kHz averaged from 32 Hz 630 Hz L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 63 of 158 2 2 COVERAGE IN THE VERTICAL PLANE Flat V DOSC Array Flying or stacking V DOSC enclosures with no angular spacing between enclosures produces a flat array that behaves acoustically as a continuous isophasic line source that radiates a cylindrical wavefront The cylindrical wavefront expands in the horizontal dimension on
159. flat surface where it is possible to roll V DOSC enclosures into position preferably from behind the installation location but it is also possible to fly the system with enclosures lined up perpendicular to the rigging points eg from the floor along the front of a stage MECHANICAL DATA L ACOUS TICS recommendations Results within 202 error Dimensions 3L max 30 E 148 E 5 48 f REAR et FRONT MECHANICAL parameters LOAD LOAD rotating legs ngle straps Absolute position of Center Gravity E aa 0 00 la YE 0 638 2 919 i Loads on Higaing and Motors E Rear matar load 700 52 ki rant load 51017 Hear load bet Front matar load B6729 ki NOTES Figure 92 SOUNDVISION mechanical data L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 112 of 158 v DOSC X Y Z3 2 r000 000 10 00 Sire 1 5 1 Azimut 0 0 3 ain 0 Delay 0 3 Boxes 12 FLOW array Gain to Angles 2 Site 2 Both Front 0 1 0 257 10 00 2 Y DOSZ 0 1 2 0 23 9 13 9 56 3 DOST 0 7 3 3 6 69 91 4 Y DOSZ 0 33 4 2 5 6 n 23 D 66 5 Y DOS 0 44 5 3 B 7 72 871 Y DOSC 0 5 6 3 11 8 7 33 7 75 7 YW DOSC 0 4 7 12 9 5 89 7 31 8 Y DOSC 0 7 9 14 2 646 5 88 9 Y DOSC 0 ZB 2 16 2 5 02 5 44 w DOSC 0 9 10 3 192 559 5
160. for locating laser beams during array trim and angle adjustment and on the golf course on days off In some cases tribune or balcony elevations can be determined by measuring individual step depth height and then counting the number of steps to calculate the section depth elevation The ROOM DIM sheet is provided in ARRAY 2004 to assist in calculating cutview data from on site measurements Room dimension calculation utilities are also available in the V ARRAY2 dV ARRAY and dV ARRAY2 sheets see Figure 46 for details L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 67 158 Note The calculation of elevation 22 is susceptible to errors in distance measurements and should always be verified with a tape measure or laser rangefinder whenever possible Combined distance angle measurements are typically more accurate than distance only measurements when calculating 22 Laser Elevation Measure Laser Elevation or Laser Elevation 01 Di D2 D3 22 0 hasse Room Dimension Sheet Calculation 2 22 Figure 46 Parameters for the ROOM DIM Utility Sheet in ARRAY XZ cells can be used to enter additional room features such as balcony profiles stage proscenium details FOH mix position etc In V DOSC V ARRAY2 cells the designer enters the number of V DOSC enclosures 16 maximum the offset distance in the x dimension elevation o
161. full details on angle strap calibration issues refer to Technical Bulletin TBO402 Angle Straps BUMPER uL e E im FU E p Figure 114 Angle strap calibration L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 154 of 158 APPENDIX 9 V DOSC Rigging Certification Lacousrics DECLARATION OF CONFORMITY For the product Catalog V DOSC Description L ACOUISTICS V DOSC loudspeaker enclosure i Dimensions 1300 mm x 434 mm x 565 mm x Hx 1 Material 71 A i Baltic birch plywood t with internal and external steel bracing side mounted aluminum track Supplied with the following accessories 2 x U pin MC DOAXE Optlonal accessories ANGLE STRAPS BUMPER 0 75 1 3 2 3 4 Product Origin Country of origin of the product France Country of origin for components of the product EEC The V DOSC loudspeaker enclosure is intended for overhead suspension below the BUMP rigging structure ar stacking top of the BUMP2 rigging structure The fallowing chart indicates the safety factor when using the V DOSC system according to the conditions described in the V DOSC OPERATOR MANUAL Version 3 2 or later 1600 3597 Ibf 1 Hur Ora Parece DCE NDICRC paga 2 L ACOUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc
162. g explanation provides a more intuitive description of WST criteria with the intention of describing where the ideas for the research that finally led to WST came from Returning to the interference problem introduced in Appendix the time frequency relationship can be expressed in a different way i e in the distance wavelength domain Since c f i e wavelength speed of sound divided the frequency ot i e path length difference speed of sound times the arrival time difference pressure cancellations occur when the path length difference between two wavefronts arriving at an observation point M is Qn 1 A 2 where n is an integer We can therefore conclude that discrete sound sources produce a totally incoherent wavefront due to comb filtering effects as soon as the path length difference between the sources to a given point is greater than 2 2 half a wavelength Let s consider a line array or column of discrete sound sources providing almost equal pressure levels at M We want to find the conditions for constructive coupling of the sound sources for a given frequency f c Assume that the time of the first arrival at M of this multiple source wavefront is t d where it is seen in Figure 103 that the first arrival is due to source i physically the closest source to the listener position M Figure 103 Destructive interference ring for a line array at observation point
163. gs 93 and 94 Pretilting is important so that ratchet straps are tensioned while the array is in its final focus orientation and the centre of gravity for the array is correct Using a handheld inclinometer on the bottom enclosure tension ratchet straps so that the bottom enclosure site angle is equal to Site Angle N as calculated in ARRAY 2004 or SOUNDVISION where the number of enclosures 28 65 degrees for the example in Figs 93 and 94 This procedure will provide the correct vertical coverage angle for the system 27 15 degrees for the example in Figs 93 and 94 When the system is flown to the actual trim height Site Angle will have to be readjusted using the remote inclinometer readout or with reference to the top cabinet laser see below since chain motors typically do not run at exactly the same speed if the relative load distribution between them is different if the system is pointing upwards or downwards Note DO NOT OVERTIGHTEN RATCHET STRAPS especially if the array is tilted upwards In general the goal is to simply take the slack out of the angle straps Overtightening ratchet straps can increase the angle between enclosures up to additional degree per cabinet by closing the gap at the rear of the enclosures similar to what happens for a stacked system due to gravity Important things to note concerning the use of ratchet straps Tightly ratcheting flown arrays is not recommended for the following re
164. he equivalent of a chaotic wavefront If we throw in a single larger stone having total size and weight equal to the handful of pebbles then we again see a coherent circular wave as for the case of the single pebble only now with a much larger amplitude If all of the individual pebbles could be glued together this would provide the same effect as the larger stone This illustrates the thinking behind V DOSC if we can build a single sound source from a number of individual speakers that can be separated for transport and handling then we have achieved our goal i e to create a modular sound reinforcement system where the individual loudspeaker enclosures couple correctly when arrayed together so that the system behaves as the equivalent of a coherent line source array This was the initial specification at the outset of the V DOSC R amp D program to design a single sound source that was completely modular predictable and adjustable L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 11 of 158 AAAA Figure Wavefront interference for conventional sound reinforcement system compared to a sculptured V DOSC wavefront WAVEFRONT SCULPTURE TECHNOLOGY BACKGROUND As early as 1988 a preliminary system named Incremental had proven the feasibility of Wavefront Sculpture Technology From this experimental concept further theoretical research was conducted by Professor Marcel Urban and Dr Christian Heil and findings were publ
165. hed to the input sensitivity of the L ACOUSTICS LA48a 9 5 dBu and the recommended power handling for each section so that system protection is performed by a combination of the limiting circuits of both power amplifier and digital signal processor NOTE Setting limit thresholds to the amplifier input sensitivity is important since this calibrates the output meter display of the crossover to correspond to the amplifier clip point This gives the system operator a direct visual indication as to how hard the system is being operated The L ACOUSTICS LA48a is an excellent power match for the V DOSC system and power amplifier clip limiting circuitry is sonically very transparent The LA48a clip limiter works by monitoring the output signal and comparing the distortion produced between the input and output of the amplifier If the distortion exceeds 1 THD for any reason voltage or current clipping the limiter reduces the input signal proportionally 2 msec attack 150 msec release Under normal operation LA48a clip limiting is inaudible and L ACOUSTICS recommends leaving the Channel A and B clip limiters switched on rear panel button depressed at all times Limiter thresholds are user accessible and exact settings will depend on individual engineer preferences and the type of music or application which in turn determines how hard the V DOSC system is being operated When additional protection is desirable limiter thresholds can be lowered to m
166. hows the coverage of different elements of a stadium system consisting of four main arrays 15 V DOSC 3 dV DOSC four distributed front fill arrays 3 dV DOSC one centre cluster 6 dV DOSC eight distributed balcony fill arrays i 2 RR RRR DEL1 DEL2 DEL3 DEL4 DELS DEL6 DEL7 DEL8 5 60 78 46 Figure 54b Stadium example plan view of full system impact coverage L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 80 of 158 FOH SYSTEM BALCONY FILL SYSTEM 8 x 6 dV DOSC OFFSTAGE FILL SYSTEM LL RR FRONT FILL SYSTEM 4 x 3 dV DOSC Figure 55 Stadium example rear perspective view of 1 10 kHz SPL Mappings L ACOUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 81 158 SOUNDVISION ARENA EXAMPLE The following SOUNDVISION example Palais Omnisport de Paris Bercy POPB Paris France shows the coverage of different elements of an arena system consisting of two main arrays 15 V DOSC 3 dV DOSC two offstage fill arrays 12 dV DOSC eight distributed front fill enclosures 112 14 25 Figure 56 Arena example rigging plot Figure 57 Arena example plan view of full system impact coverage L ACOUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 82 158 Figure 59a Arena example rear perspective view of full system SPL map 1 10 kHz L ACOUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 060
167. ibutions due to subwoofers L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 70 of 158 UPSTAGE DOWNSTAGE ach nas MOTOR Z AXIS 4 HEIGHT BUMPER 1 05 ELEVATION SITE ANGLE NEXT e SITE ANGLE 2 ANGLE 1 TO HEXT BOTTOM ELEMENT ELEVATION lt SITE ANGLE 3 ANGLE 3 T TO NEXT 4 SITE ANGLE 7 ARRAY HEIGHT ARRAY DEPTH Figure 48 ARRAY 2004 Geometric Data for V DOSC The Nominal Vertical Coverage Angle of the array is calculated as the sum of the entered inter enclosure angles This coverage becomes effective at and for all frequencies higher than F the vertical coverage angle is less than this nominal vertical coverage angle Above the vertical coverage angle perfectly matches the nominal value Some beaming vertical coverage narrowing may occur at especially when the array is of constant curvature type Further theoretical details related to the calculation of F and F are given in Appendix 6 Finally MECHANICAL DATA gives an estimate as to the rear versus front motor and rear rotating leg versus BUMP angle strap load distribution These load distributions depend on the size and shape of the array as well as the array site angle equal to Site 7 1 which in turn affect the location of the centre of gravity L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 71 of 158 Important things to note ARRAY WEIGHT includes V
168. ical music and speech reinforcement maximize A weighted SPL output obtain a better utilization of available power resources optimize LO and HI presets for their target applications LO speech classical music or proximity use rock electronic music long throw applications 1 1 111111 250 Mn dh EE 2 Figure 35 Spectral balance SUB LOW versus MID HI Sections Ik Note For LO presets to obtain the spectral balance that was provided in presets and earlier simply reduce the mid high section output gains by 2 dB to 5 dB 5 dB ip zi BE 5 221 ik ch Figure 36 Spectral balance for SUB LOW versus MID HI Sections V6 presets and earlier 3 WAY STEREO PRESETS 3WX PRESET The 3WX preset features a 30 Hz high pass filter for the V DOSC low section combined with optimized low frequency shelving equalization With the preset significant LF energy can be obtained from V DOSC itself and for some applications classical music or speech reinforcement V DOSC can be used without additional subwoofers For larger systems there is the added benefit of improved low frequency pattern control since the larger the V DOSC array the lower in frequency that pattern control extends The 3WX preset is intended for standalone applications without subwoofers or for AUX SUB drive using the 58218 DELAY ARC 80 Hz or 58218 LCR 80 Hz presets
169. in the coverage overlap region between main FOH and offstage fill arrays L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 49 of 158 1 11 MD24 MULTI DISTRO PANEL L ACOUSTICS MD 24 MULTI DISTRO RIGHT Figure 33 MD24 Multi Distro Panel As seen in the system block diagram of Figure 6 the MD24 Multi Distro panel is used onstage for distribution MC28100 MULTI return snake lines that originate from the CO24 Control Output panel located at FOH The MD24 panel can be packaged separately and located either stage left or right depending on physical constraints regarding snake runs or alternatively can be mounted in the amplifier rack that is first in line for patching purposes DOM2 AMP LINK cable is run from the Multi Distro panel to the appropriate 19 CA COM connector of the first amplifier e g B lines for FOH left if the amplifier rack is located stage right AMP LINK cables are then used to connect subsequent stage right amplifiers so that all receive B lines including subwoofer and 2 way amplifier racks which are configured using SUB and 2 WAY COMB connectors respectively A CROSS LINK cable is then used to distribute C lines for FOH right from the MD24 Multi Distro panel cross stage to the stage left amplifiers These racks are connected in the same way using AMP LINK cables and similar connections are performed for the A and D lines to accommodate Left Left and Right Right arrays as necessary
170. ion 4 6 29 2005 Page 58 of 158 DP224 V DOSC PRESETS PRESETNAME ______________ 6 __ MEM OUT Source OUT2 Source OUT3 Source V DOSCiLO _ 4wa 10 5084 V DOSCLO V DOSCMID A 4 5084 VDOSCLO VDOSCMID A T Dc wma c V DOSC i AUX LO 1 B 16 V DOSC LO V DOSC MID A V DOSC HI A W DOSCXAUXLO 1 8 18 V DOSCLO A V DOSCMID A _ 5 18 V DOSCMID A V DOSCHI A a a tr Pe ee ee ae ee ee ee ee ee dV DOSC 2W 80 LO dV DOSC LO A dV DOSC HI A dV DOSC LO B SS ee ee Pee a ee dV DOSC 3W 80 dV SUB LO 24 dV SUB A dV DOSC LO A dV DOSC HI A a eee o Sy ea ee DI D ee ees ee eee ni 3W 58118 LO 28 dV DOSC LO A dV DOSC HI A ee ee el ee ee ee SB218 LO 32 dV DOSC LO A dV DOSC HI A I ae ee ee ees x ae ae ee on ey Sar ES SaaS 2S ee
171. ion purposes front and rear doors must always be removed during operation A high impact resistance polyethylene cover provides protection for the rack during transport so that no external case is required Four recessed Aeroquip flytrack sections are mounted on both sides of the amplifier rack for flown applications Recesses in the top cover of the amplifier rack allows racks to be stacked on top of each other with the casters still attached It is also possible to remove the casters on one amplifier rack place it on top of a second amp rack and then mechanically bolt the two racks together Overall the L ACOUSTICS RKI2U amplifier rack provides an extremely efficient package in terms of power versus size and weight while at the same time maintaining flexibility for smaller scale and distributed system applications L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 43 of 158 4 x LA48a plus PADO4a 4 x LA48a plus 2 x PADO2a
172. ions include 3 dB SPL reduction with doubling of distance i e arrays have been designed for constant impact spacing using their respective Cutview sheets anechoic or reflection free conditions direct sound only Input Data Just as for cutview sheets input data cells are in black and results are displayed in red To define a plan view of the audience area the user inputs x range and y distance off centre coordinates in the Contour and Contour 2 cells A mirror image drawing scheme is used so that only half the room needs to be defined and after coordinates are entered the display of the audience area is updated when the SCALING button is pressed It is only necessary to define Contour however Contour 2 is useful to represent balconies stage thrusts proscenium opening FOH location etc When V DOSC and dV DOSC arrays are defined in 1 2 and dV ARRAY 1 2 Cutview sheets respectively they are automatically displayed in the H ISOCONT sheet with the x location of each array referenced to the defined Offset Distance taken from each arrays respective Cutview sheet The parameter Isocontour at Distance m refers to the throw distance for the top enclosure of the respective array and is given relative to the defined Offset Distance The user then enters the Console Output Signal dBu for each array i e output level of the mixing desk 0 VU 4 dBu and the Continuous A weighted SPL is tabulated corresponding
173. irectly on axis with one side of the system and thin offstage These effects are due to the path length difference interference effects that are inherent in any left right system which in turn produce frequency and position dependent peaks and dips Tradeoffs Between Intelligibility and Stereo Imaging The left right configuration has the advantage of being able to reproduce effects of spatialization and localization The area over which these effects is audible depends on the separation of the two arrays and the orientation of the left array with respect to the right array defined by the intersection of the isocontours for both arrays The more the arrays are rotated or panned onstage toed the greater the area over which stereo imaging is experienced The less they are rotated onstage and the more they are aimed offstage the less stereo imaging is audible Typically for concert applications L R arrays are separated 15 20 meters and used at zero degrees or panned 2 5 degrees offstage Experience has shown that this provides the best tradeoff between stereo imaging evenness of horizontal coverage and reduction of the potential for build up of low frequency and upper mid bass energy in the centre Note Use of the delta plate rigging accessory provides a convenient way to vary the panning angles of flown L R systems and adjust the amount of overlap and stereo imaging There are also tradeoffs with respect to intelligibility when ai
174. is that eq adjustments can be performed offline and it is not necessary to make excessive noise during the system eq process which can be disruptive to other people working on the installation Note For 5 format presets V DOSC INFRA X 4W fullrange ouput 5 input A can be used to monitor the effects of input parametric equalization which is used for system eq L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 125 of 158 More sophisticated measurement instruments can also provide additional information related to room acoustics that can be useful for the tuning process for example at various frequencies and waterfall plots that help identify low frequency resonances for a given room Measurement Tips Performing accurate measurements and interpreting them correctly requires being aware of a few potential problems Here are some typical ones e Measure one source at a time Measuring two sources radiating the same signal simultaneously will display interference cancellations which occur due to path length differences unless the microphone is exactly equi distant from both sources Place the microphone on the floor When the measurement microphone is mounted on a stand or near reflecting surfaces the frequency response will show a cancellation in the low mid frequencies due to the path difference between the direct signal and the reflected signal which arrives a few milliseconds later The resulting frequency respo
175. ished in 1992 Sound Fields Radiated by Multiple Sound Source Arrays AES 3269 The theory that was developed defines the acoustic coupling conditions for effectively arraying individual sound sources Relevant parameters include wavelength the shape and surface area of each source the curvature of the wavefront radiated by each source and the source separation WST coupling conditions can be summarized as follows An assembly of individual sound sources arrayed with regular separation between the sources on a plane or curved continuous surface is equivalent to a single sound source having the same dimensions as the total assembly if and only if one of the two following conditions is fulfilled Shape The combined surface area of the wavefronts radiated by the individual sources of the array fills at least 80 of the target radiating surface area see also Condition 3 2 Frequency The source separation defined as the distance between acoustic centers of the individual sources is smaller than half the wavelength at all frequencies over the bandwidth of operation generally this criteria is satisfied at lower frequencies since wavelengths are sufficiently large These two conditions form the basis of Wavefront Sculpture Technology WST L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 12 of 158 STEP EQUIVALENT EQUIVALENT STEP e H STEP STEP W PROVIDED THAT CRITERIA N CRITERIA N 2
176. ith coplanar symmetric arrangement of loudspeaker components Includes removable front dolly not shown DOSC COV Protective cover for V DOSC enclosures comes in pairs Constructed of rugged cordura material and padded for extra protection dV DOSC Active 2 way loudspeaker enclosure meeting WST criteria with coplanar symmetric arrangement of loudspeaker components Used with V DOSC for down fill up fill long throw offstage fill stereo in fill or distributed front fill Note for full details see the dV DOSC user manual available for download on www l acoustics com FLIGHT dV Flight case for transport of three dV DOSC enclosures V DOSC DOSCOVx2 FLIGHT dV Figure 9 V DOSC system loudspeakers plus accessories L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 23 of 158 RIGGING ACCESSORIES 5 6 7 8 9 10 11 2 Flying bumper for rigging V DOSC array up to 16 enclosures deep Can also be inverted and used as an adjustable base for stacking a V DOSC array BUMPDELTA Delta plate used to attach two motors to BUMP2 allowing for pan adjustment of a flown V DOSC array ANGLE STRAPS Used to provide spacing between V DOSC enclosures when stacked or flown Values 0 75 or 5 57 1 39 2 3 4 Part Codes BUMP24 251 BUMP25 BUMP26 BUMP27 SPACER Used with ANGLE STRAPS to provide the desired spacing between V DOSC enclosures when stacked or flown Part C
177. ive interference zones ESE EEE 4 2 ncre me nts A gt ma Figure 105 Destructive and constructive interference rings for a line array at observation point L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 145 of 158 We can now compare the number of sound sources inside the constructive rings to the number of sources inside the destructive rings When these numbers are almost equal sound sources cancel each other and produce an incoherent wavefront at M When there are significantly more sound sources within the constructive rings a coherent wavefront is produced at M It should be noted that this method is due to Fresnel he used this type of analysis to describe light interference at the beginning of the century we repeat this analysis for different locations we can draw a that shows where the sound field is coherent or incoherent When it appears that there is no constructive wavefront over a given area the wavefront is chaotic If we can define an area where the wavefront is highly constructive the sound pressure level will be much higher than in a destructive area We can thus define the effective coverage of the array for this given frequency The goal for the sound designer is to clearly identify an area where the wavefront is coherent not just for a given frequency but for the whole operating bandwidth of the sound source How can we a
178. k drum is effective and the distance can be determined geometrically think Fresnel In other cases time alignment with the drum monitor sidefill monitors or the monitor front line may prove more effective Generally the loudest thing on stage makes for a good time alignment reference In smaller venues where monitor system energy reflects off the back wall and ceiling in addition to the direct sound generated by the band system predelay is not L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 124 of 158 as straightforward and the best results are obtained subjectively Predelay can be applied before or after performing the detailed measurements outlined in the following section just be sure that the correct relative delay is also applied to subwoofers fill systems and downfill systems Finally many users have reported good results when using program compression limiting on the main mix i e before the digital processor inputs Using a high quality compressor limiter eg SSL dbx 1605 SIDD or other high quality equivalent and a moderate amount compression e g 2 dB with 1 5 1 to 2 1 ratio allows the mix to sit better on the system and prevents transients from jumping out of the mix In addition calibrating limiter threshold to the digital processor clip point provides an additional level of system protection by preventing digital clipping of the processor inputs Program compression limiting before the processor input
179. l so that signals arrive in phase and sum while destructive or constructive interference can occur off axis depending on listener position and the frequency of interest For example if on axis to the L array and a series of Fresnel rings is drawn the R array could fall in a destructive ring and cause cancellation see Appendix 2 for more on Fresnel In general L R subwoofer arrays are only desirable for long narrow audiences where the centre build up effect is less of a problem since the venue is narrow and we don t mind focusing energy up the middle Past attempts at reducing the power alley effect for L R arrays have included complementary comb filtering applied to the left and right signal feeds for the subwoofer arrays see Use of Stereo Synthesis to Reduce Subjective Objective Interference Effects The Perception of Comb Filtering Augspurger et al AES preprint 2862 New York 1989 The main limitations of this approach reported to be changes in timbre and a potential loss of overall energy The preferred option is either an LCR configuration or electronic delay processed systems see Sections 3 5 2 and 3 5 3 Despite the fundamental limitations of subwoofer arrays some recommendations and basic guidelines are made in the following Figures 75 a b c and d show techniques for optimizing low frequency tonal balance over the audience while 75 e shows a non recommended configuration In Figure 75 a ground st
180. lease refer to their respective user manuals www lake com au www xta co uk www bss co uk NOTE ALWAYS REFER TO THE PRESET DESCRIPTION SHEET FOR YOUR DSP WHEN SELECTING PRESETS AND CONFIGURING YOUR DRIVE RACK 1 14 OEM FACTORY PRESETS OEM factory presets are intended to serve as a reference for all Qualified V DOSC Technicians and Certified V DOSC Engineers According to L ACOUSTICS company policy key parameters are software protected and preset data or passwords are not communicated in order to preserve quality control confidentiality and to maintain the integrity of presets as part of the V DOSC standard A lot of engineering and real world testing goes into determining optimum V DOSC presets detailed polar measurements and weighted spatial averaging are used to determine component equalization crossover points and time alignment delays for example As a result V DOSC presets give the user an optimum starting point system tuning should be done using band attenuation subwoofer time alignment and system equalization using input parametric filters not by altering presets for the following reason Without proper instrumentation and spatial averaging adjustments made at one location e g the mix position are not optimum at all other locations within the defined coverage pattern of the system When made by ear such adjustments are often misguided the user may be in a local room mode low frequency pressure maximum or mi
181. led screwed and rabbeted angles internally braced cabinet construction Maroon gray Black epoxy coated perforated steel with acoustically transparent foam Integrated flying hardware and handles 1300 mm x 434 mm x 565 mm 51 27 x 17 1 x 22 2 Weight 108 kg 238 Ibs 9 5 kg 21 Ibs for dolly L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 132 of 158 Figure 97 V DOSC Enclosure Line Drawing L ACOUSTICS V DOSC Manual Version 4 6 29 2005 hie He de IH IH Page 133 of 158 7 2 58218 SUBWOOFER SPECIFICATIONS Frequency Response Usable Bandwidth Sensitivity 2 83 V at Im Power rating SPL Output enclosure 2 enclosures 4 enclosures Impedance Components Material Finish Grill Features Dimension WxHxD Weight 28 Hz 140 Hz 3 dB 25 Hz 200 Hz 100 5 dB SPL 28 200 Hz 68 Vrms 100 Wrms 4400 Wpeak long term pink noise with 6 dB crest factor 30 dB continuous 36 dB peak 36 dB continuous 142 dB peak 142 dB continuous 48 dB peak 4 ohms 2 x 18 cone bass reflex 4 5 edgewound copper voice coil Baltic birch plywood Sealed screwed cabinet construction Maroon gray Black epoxy perforated steel with acoustically transparent foam Integrated flying hardware handles 300 mm x 550 mm x 700 mm 51 2 x 21 7 x 27 6 106 kg 233 lbs 9 5 kg 21 Ibs for dolly L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Figure
182. lls For the product Catalog Item BUMPDELTA Dimensions 606 mmx333 mm x 30 mm W x H x T L ACOUSTICS hereby declares that the above product conforms to The Machinery Directive 98 37 CE Part 4 Lifting Accessories Material Steel 10 mm thickness 2 Rules for the Design of Hoisting Appliances Furopean Federation of Materials Handling and Storage Equipment FEM 1 001 Supplied with the following accessories 3 x Shackle Diameter 22 mm WLL 2T CA MAN22 Product Origin Country of origin of the product France Country of origin for components of the product EEC 2 BUMPDELTA rigging accessory allows for the use of 2 lifting motors for rear Established at Marcoussis France on the 22 of September 2003 suspension of the BUMP rigging structure in order to change the horizontal orientation of the V DOSC loudspeaker system The following chart indicates the Signature of L ACOUSTICS representative safety when using the BUMPDELTA according to the conditions described In the V DOSC OPERATOR MANUAL Version 3 2 or later BUMPDELTA Jacques Spillmann Chief Engineer Manufacturing 1 Aue Varc cie Fonte de juvenes 8 45 Arcona tpi DCE BLIMPDELT paga 1 2 DCE BUMPDELTA paga 2 2 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 157 of 158 racy DECLARATION OF CONFORMITY For the product Catalog Item ANGLE
183. ly and is defined by the section of a vertical cylinder over a given distance The height of this section corresponds to the height of the array defined by the top wall of the top enclosure and the bottom wall of the bottom enclosure and the coverage angle corresponds to the 6 dB horizontal coverage angle of V DOSC try to visualize a 90 cheese wedge or a piece of cake Line source Cylindrical Wave Expands in horizontal dimension only At 2R surface area increases 2 times 3 dB attenuation According to Fresnel analysis a cylindrical wavefront is radiated by a line source array over a certain distance and then transforms into a spherical wavefront In spherical mode the wavefront expands in two dimensions thus producing a SPL attenuation of 6 dB with doubling of distance In cylindrical mode the wavefront expands linearly with distance in the horizontal plane only thus producing only 3 dB of attenuation when doubling the distance The boundary between cylindrical and spherical wavefront propagation regions depends on the frequency and length of the line source see Appendices 5 and 6 for more details Since V DOSC is in essence more efficient at projecting HF energy than LF the net result is that for large distances the tonal balance is progressively tilted by a HF enhancement For longer throw distances this tilt in tonal balance is offset by air absorption in open air situations and by both building material absor
184. ments can be conducted on FOH For LCR subwoofer arrays refer to Section 3 5 3 for recommendations concerning measurement microphone locations for time alignment Mute the highs and mids Individually feed the low channel of the main L arrays then the L subwoofers with pink noise and adjust the crossover output levels to obtain the same measured level and or change the measurement microphone reference distance to obtain the same measured level Invert the sub polarity from it s OEM starting point 4W INFRA or X presets change from ve to ve X AUX preset change from ve to ve Feed L subs and L lows with pink noise and fine tune the delay adjustment up to 3 msec from the geometric pre aligned delay to obtain maximum cancellation L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 127 of 158 Change the polarity of the subs back to the normal values and confirm that maximum summation is obtained 4 INFRA or X presets subs ve polarity X AUX preset subs ve polarity Apply the same delay to subs L if measurements carried out Note Alternatively if a time domain measurement system is available follow the guidelines outlined in Section 1 15 to time align the sine wave signature of the sub and low channel impulse responses 7 Check the overall tonal balance of one side Select the desired preset LO or HI shelving eq and perform band attenuation using DSP ou
185. ming arrays Psychoacoustically improved intelligibility is obtained when the isocontours of both arrays do not overlap too much Provided that audience coverage is correct intelligibility is optimal when only one array radiates on a given audience area If two arrays are to cover a common area intelligibility losses result when the distance separating the two arrays becomes too great A standard distance of 20 m 65 ft is acceptable however if greater separation is specified one should avoid rotating the arrays onstage too much this emphasizes arrival time differences between the arrays thus degrading intelligibilty The decision whether to emphasize intelligibility or stereo imaging mainly depends on the application For music applications more overlap is desired and for speech reinforcement less is more appropriate L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 88 of 158 30 110 120 130 140 150 2 964 110 120 130 140 150 Vm Optimizing coverage and intelligibility Optimizing stereo imaging Figure 64 Tradeoffs between intelligibility versus stereo imaging 3 2 2 LEFT CENTRE RIGHT LCR CONFIGURATIONS Although it can be sometimes difficult to negotiate the centre position from a visual standpoint LCR systems offer more flexibility in optimizing audience coverage with the potential for improved intelligibility more even horizontal tonal balance and better image localization compared with
186. more detailed descriptions in Sections 1 2 through 1 7 Please note that specific multi conductor connector selection for system drive remains open for the user to define although L ACOUSTICS does offer a specific connector type that is supplied with turnkey systems L ACOUSTICS recognizes the fact that multi conductor snakes and connectors represent a significant investment and many users already have their own internal standard that they must adhere to Therefore this part of the system standard remains flexible System elements that must remain standard in order to ensure compatibility include digital signal processors OEM factory presets channel assignments for signal distribution power amplifiers and power amplifier rack panels General block diagram representations of V DOSC system components cabling and signal flow are given below in Figures 6 8 Please refer to these block diagrams for a system overview NOTE V DOSC systems that do not comply with the system standard are considered non approved by L ACOUSTICS For the case of non standard systems L ACOUSTICS does not accept responsibility for misuse or misoperation and in some cases warranty coverage may be considered void L ACOUSTICS strongly encourages all users to comply with the recommended standard as closely as possible in order to maintain approved status L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 19 of 158 DIGITAL al 2 PROCESSOR 2 5
187. mplifiers not included PADO2a AMP PANEL Amplifier panel supplied with RK122a suitable for 2 amplifier rack configuration Single 8 pin female CA COM connector for loudspeaker connection in parallel with 4x Speakon connectors two male 19 pin CA COM connectors for signal distribution input through COMB connector for selecting 2 way 3 way or subwoofer operating modes 4x male XLR and 4x Speakon fanouts on the internal side for connecting to amplifier inputs and outputs Note PADO stands for PATCH DOSC PADO4a AMP PANEL Amplifier panel supplied with RK124a suitable for 4 amplifier rack configuration Dual 8 pin female CA COM connectors for loudspeaker connection two male 19 pin CA COM connectors for signal distribution input through 2x COMB connectors for selecting 2 way 3 way or subwoofer operating modes 2 pairs of 4x male XLR and 4x Speakon fanouts on the internal side for connecting to amplifier inputs and outputs COMB CONNECTOR Routes desired input lines from the male 19 pin CA COM connector to the appropriate amplifier inputs allowing RK122a or 24 amplifier racks be configured in 2 way dV DOSC 5 3 way V DOSC KUDO or subwoofer 58218 operating modes COMB connectors D2WAY D3WAY and DSUB respectively Additional COMB connectors are available for use with 2 or 3 way format systems D2WA D2WB D2WSTEREO D3WA D3WB DSUBA DSUBB and a COMB connector kit for subwoofer array signal processing
188. nce sitting at varying distances from the system and a constant curvature array would produce excessive SPLs in the first rows compared to the furthest rows even if the vertical coverage angle is correctly matched to the audience geometry Therefore a constant curvature array is generally not useful for most applications If this configuration is used the gain of the amplifiers powering the high frequency section of the lower V DOSC enclosures may need to be progressively reduced however such attenuation results in a global loss of energy L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 65 of 158 Variable Curvature V DOSC Array Since individual V DOSC enclosures radiate a flat isophasic wavefront it is possible to focus energy in a given direction and increase the SPL by reducing the angles between enclosures Conversely by increasing the angle between enclosures up to a maximum of 5 5 it is possible to lower the SPL in another direction This is the basic principle that allows energy to be distributed uniformly throughout the audience and variable curvature arrays are used to adapt both the coverage of the system and the SPL distribution to match the specific audience geometry according to WST Condition 4 Shaping the VERTICAL ISOCONTOUR is the key to Wavefront Sculpture Technology SOUNDVISION and ARRAY 2004 simulation programs allow the designer to shape the vertical isocontour of a V DOSC array The following sections give more c
189. ndards and are considered as subsets of the large scale setup A large scale V DOSC system typically consists of Left Left L L Left L Right R and Right Right V DOSC arrays Each of the four arrays can have associated 2 way dV DOSC downfill enclosures and 58218 subwoofers Therefore each L L L R and R R array requires 6 drive channels 3 for V DOSC 2 for dV DOSC and for 582185 Since there are 4 arrays this requires 24 drive channels total The 84 pin Whirlwind MASS W6 connector accomodates these 24 drive channels 72 lines leaving 14 additional lines available It is important to have discrete drive for all four arrays for several reasons a Discrete drive allows for the relative time alignment of all 4 arrays i e typically the L array will act as a time reference for the L L array while the R array acts as a time reference for the R R b Different sized arrays will require different band attenuation and equalization i e typically the L L and R R arrays used for offstage coverage are smaller in terms of the number of enclosures c Discrete drive for all four arrays allows for the creation of stereo over larger audience areas i e using the console s matrix outputs the stereo left signal can be applied to the L and R R arrays while stereo right can be sent to the R and L L arrays De correlating the L L versus L signals and R R versus R by applying stereo feeds also helps to reduce the effects of audible interference
190. nding on the observer location M SPL fo Ea Jig f Figure 102 Comb filtering due to path length differences between sources As discussed in Section 3 3 the principles of 2 source interference can be used in sound design when considering multiple V DOSC arrays since in effect the main and offstage V DOSC arrays act as 2 coherent sound sources When a separation of 6 8 metres is maintained between the 2 V DOSC arrays this shifts the first octave wide cancellation seen in Figure 102 f down to approximately 15 25 Hz and this cancellation becomes inaudible since it is shifted below the operating bandwidth of the V DOSC low section The second and third nulls 3f 56 tend to be filled in or masked by room reverberation Higher frequency cancellations 7f and higher are too tightly spaced for the ear to resolve plus focussing the aiming axes of the two arrays at different angles helps to minimize the area over which this comb filtering interaction takes place L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 143 of 158 APPENDIX 2 FURTHER EXPLANATIONS REGARDING WST CRITERIA A detailed formulation of Wavefront Sculpture Technology Criteria was developed in Sound Fields Radiated by Multiple Sound Source Arrays AES preprint n 3269 presented at the 92nd AES convention in Vienna March 1992 Further theoretical research was developed in Wavefront Sculpture Technology JAES Vol 51 10 October 2003 The followin
191. ng CA to banana leads L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 129 of 158 6 3 5 Speakers HF driver complete HP 21 HF diaphragm HS BC2 7 midrange speaker complete HP FO7I 5 speaker complete HP PHI5I 5 speaker recone kit HS PHI5I 8 speaker 220 mm magnet complete BEI8I 8 speaker 220 mm magnet recone kit HS BEI82 8 speaker 260 mm magnet recone kit old style HS BEI8I Connectors Female Panel Mount Speaker Connector 8 conductor CC 8B EF Male Panel Mount Speaker Connector 8 conductor CC 8B EM Female Speaker Connector Line 8 conductor CC 8B FF Male Speaker Connector Line 8 conductor CC 8B FM Male Extension Cable Connector Line 8 conductor CC 8B FPM Female Extension Cable Connector Line 8 conductor CC 8B FPF L ACOUSTICS V DOSC Manual Version 4 Male Panel Mount Link Connector 19 conductor 19 EM Female Link Connector Line 19 conductor CC 19 FF Speakon Connector Line 4 conductor CC4F Speakon Connector Panel Mount 4 conductor CC 4 COMB Connector 25 pin CC 25SUBDM COMB Connector 37 pin CC 37SUBDM DKIT upgrade kit for x COMB Connector DKIT Accessories Locking Pin 4 5 mm diameter for U Pins GOUP45 Lanyard for CA GOUP45 EL45 Locking Pin 6 mm diameter for dolly board CA GOUP6 Lanyard for CA GOUP6 CA EL6 Cabinet handle CA POIG Dolley board caster CA ROL Magnet for rotating leg CD AIMA
192. ng effects However this configuration can be used if electronic delay processing is applied to the individual columns of the L R arrays in order to obtain the equivalent performance of Fig 75 d L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 97 of 158 L Wrap L R subwoofer arrays d Curved L R subwoofer arrays e L R horizontal line arrays Figure 75 L R Subwoofer arraying techniques L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 98 of 158 3 5 2 CENTRAL LINE ARRAY WITH ELECTRONIC DELAY PROCESSING A central ground stacked line array optimizes low frequency SPL output since all subwoofers couple acoustically and the mirror image ground plane effect doubles the number of subs Given the same number of subwoofers the overall SPL obtained by ground stacking in this manner is higher than any other configuration An additional advantage of the centre line array is that the vertical directivity is omnidirectional this is useful for venues where there is an audience tribune Since the subwoofers are physically separate from the flown V DOSC arrays they are normally driven via aux send in either INFRA X AUX or 4W mode although the system can also be operated in 4 way mode Limitations of the central ground stacked line array configuration are as follows Tonal balance has an exaggerated low frequency contour for the closest members of the audience integrating distributed front fill loudspeakers or a stereo infill syst
193. nimum and or may be hearing a cancellation or addition due to crossover misalignment that sounds good at that specific location but what about all others Meanwhile a better result could have been achieved while preserving the power response of the system and satisfying WST conditions by using the correct OEM factory preset and a simple equalization or output channel gain adjustment or correct time alignment of subwoofers or The bottom line is that making sure that V DOSC is used properly is in everyone s best interest and it is up to the Qualified V DOSC Technician and Certified V DOSC Engineer to maintain quality control standards Quality control starts with a good sound design concept then includes detailed coverage simulation using ARRAY or SOUNDVISION to determine installation parameters accurate installation correct preset selection and a solid methodology for system tuning Restricting access to presets is in no way meant to restrict the creative process on the contrary the overall systems approach is intended to enhance it by ensuring quality control and repeatability L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 51 of 158 15 V DOSC PRESETS Preset selection depends on many parameters including the V DOSC array plus subwoofer configuration musical program and personal taste of the sound engineer In general LO presets are the smoothest while HI presets are brighter LO and HI refer to differences in the amount
194. nitally flat then multiply by the spatially averaged curve This allows you to adjust the equalizer while monitoring the effect on the spatially averaged response Duplicate eq settings for the other side of the system if L R DSPs are not stereo linked Verify the effects of equalization by repeating steps 8 9 12 Adjust the subwoofer level according to subjective taste and finalize EQ adjustments focussing on the 120 300 Hz region 4 Predelay the entire system to the desired time reference For example if the drum monitor is the loudest element on stage use a system with time delay measurement capability to measure the time delay of the drum monitor with respect to the main system Otherwise base system predelay on the geometrically determined delay 15 Repeat the eq procedure for fill systems LL RR offstage arrays front fill centre cluster etc 16 Time align fill systems to the main L arrays by locating a measurement mic in the transition region where the coverage patterns overlap 7 Listen to a variety of familiar well recorded program material 8 Walk the room and attenuate fill arrays relative to the main L system as required 19 Compare program reproduced by the system versus a pair of high quality reference headphones monitoring the output of the console Voice the system with a good quality vocal microphone 20 Verify tuning throughout the audience by walking the room and perform final adjus
195. nology and distributed sound design techniques please refer to the MID or XT User Manuals available for download on www l acoustics com L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 90 of 158 15 Figure 67 Rigging plot for L R V DOSC flown 58218 system with LL RR dV DOSC offstage fill dimensions in metres See figure 60 for a reduced footprint version of this rigging plot Experience has shown that this is a very flexible approach that can cover any type of audience and an additional advantage of multiple arrays is improved resistance to wind effects in open air situations Beyond the basic solution of coverage problems multiple source arrays open up many possibilities for creating a spatial soundscape thus providing a powerful tool for sound design and creativity see the example below 20 40 30 20 10 Figure 68 Stereo dV DOSC offstage fill system Left right program signal is applied to arrays as follows LLL left LL right L left R right RR left RRR right L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 91 of 158 3 4 SUBWOOFERS Although V DOSC is capable of radiating frequencies down to 40 Hz with good vertical directivity control the low frequency directivity control limit depends on the size of the array 58218 subwoofers are normally added to the system to extend the frequency response down to 27 Hz and increase the overall unweighted SPL Techniques for maximizing the
196. nse cancellations are not due to the system and should not be equalized More sophisticated measurement systems such as MLSSA WinMLS and TDS allow the user to apply a time window to remove such reflections from the measurement however this can be at the expense of low frequency resolution depending on the length of the time window When placing the microphone on the floor if the floor is absorbent e g thick carpet or grass in open air situations the measured response may display a high frequency loss in this case a sheet of plywood can be useful for reducing this effect on your measurements Time aligning the sine wave characteristics of the sub and low section impulse responses provides the best sub low summation results see Section 15 Measurement systems such as MLSSA or WinMLS are recommended for this purpose since they measure the impulse response directly in the time domain and it is possible to obtain a clean impulse response even in highly reverberant indoor environments Equalizing subwoofers is difficult since measurements taken at a single location can be misleading Indoors there are room modes to consider and you may be located in a pressure null or maximum depending on the location and the frequency Be sure to verify the effect of your adjustments throughout the audience by walking the room and performing spatial averaging Watch out for wind effects and be sure that measurements are stable and rep
197. nstructed according to specific ratios between depth height and cone angle in order to produce a flat constant phase wavefront Tight manufacturing tolerances are obtained through the use of computer aided design and manufacturing CAD CAM techniques in the fabrication of the DOSC waveguide As shown in the AES preprint entitled Wavefront Sculpture Technology the deviation from a flat wavefront must be less than 2 4 at the highest operating frequency this corresponds to less than 5 mm of curvature at 16 kHz and experiments have shown that the DOSC waveguide provides less than 4 mm of curvature at this frequency DOSC waveguide technology is patented on an international basis n 0331566 in Europe n 5163167 in North America L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 149 of 158 APPENDIX 5 THE BORDER BETWEEN FRESNEL AND FRAUNHOFER REGIONS This appendix summarizes theory presented in Sound Fields Radiated by Multiple Sound Source Arrays AES preprint n 3269 presented at the 92nd AES convention in Vienna March 1992 Let s assume that the V DOSC array is flat and radiates a cylindrical wavefront The emerging wave will progressively expand to a spherical wave at a certain distance which depends on both the frequency and the height of the array V DOSC ARRAY Dy Chorder FRESNEL FRAUNHOFER nearfield farfield CYLINDRICAL SPHERICAL Figure 111 Illustration of the Fresnel and Fraunhofer
198. nt and COMB connector summary DSP OUTPUT 2W STEREO 3W STEREO CO6 CO24 COMB CONNECTOR CHANNEL SELECTION INPUT 1 2 SUB A LO A HI A SUB B SUB B LO B LO B HI B HI B This signal distribution scheme allows for logical patching between digital signal processor outputs and or 24 inputs for 2 way stereo and 3 way stereo format presets i e channels are patched 1 1 2 2 3 3 etc This helps eliminate potential sources of error due to mispatching and in addition it is not necessary to repatch DSP outputs when changing between stereo 2 way and 3 way presets W Operating modes amplifier rack channel assignments and cabling plus loudspeaker enclosure combinations for the L ACOUSTICS 22a amplifier rack PADO2a plus 2 x LA48a are as follows 2 WAY STEREO PRESETS RK122 RK122 RK122 HI A 2W ST DO10P DO2W DO10P DO2W DO10P DO2W or or or DO7 or 25 DOFILL DO7 or 25 DOFILL DO7 or 25 DOFILL or or or DO2W CC4FB SP7 SP25 DO2W CC4FB SP7 SP25 DO2W CC4FB SP7 SP25 3 3 dV DOSC ARCS XT 3 3 dV DOSC ARCS XT 3 3 dV DOSC ARCS XT 3 WAY STEREO PRESETS RK122 RK122 RK122 RK122 SUB A SUB A SUB B SUB B SUB A SUB A SUB B SUB B SUB A SUB B DO10P DO3W DO10P DO3W or or DO10P DOSUB DO10P DOSUB DO7 or 25 DO3WFILL
199. nt starting point for system tuning Frequency response is flat between 300 Hz 4 kHz and from 40 160 Hz 10 dB low frequency contour is built into the preset At higher frequencies the response 15 either flat LO presets or has additional high frequency shelving HI presets It is always a good idea to set the ratios between mid high low and sub sections using the output channel gains of the DSP before proceeding to perform detailed measurements and equalization Output gain scaling sets the tonal balance of the system by compensating for the size of the array low end coupling and the V DOSC SB218 cabinet ratio low sub coupling In general as the array size doubles the low end increases by 6 dB and the mid high response by 3 dB so the low frequency contour for V DOSC without subwoofers scales as follows V DOSC 10 dB 2 V DOSC 13 dB 4 V DOSC 16 dB 8 V DOSC 19 dB 16 V DOSC 22 dB As a result for larger V DOSC arrays 12 16 enclosures the mid and high sections can both be increased by 3 6 dB or the low section attenuated to compensate for the enhanced low end coupling that occurs Output gain scaling should also be performed to compensate for the V DOSC SB218 cabinet ratio Standard output gains apply to a 3 2 V DOSC SB218 ratio for 2 1 ratio subwoofer gain should be scaled 2 dB for a 1 1 ratio the low section output gain should be scaled 4 dB see Section 15 for further details L ACOUSTICS V DOSC Manual
200. o arrays In addition by focussing main and offstage fill arrays at different panning angles audible comb filtering interaction is lessened since the overlap region between the two arrays is reduced In some situations more overlap may be desirable and cross panning arrays will help provide stereo to a greater portion of the audience while de correlating the signals between adjacent arrays to further reduce audible interference effects i e arrays can be run in cross panned stereo and fed as follows L L right program signal L left program signal R right program and R R left program The main L R FOH arrays are normally physically larger than the LL RR offstage fill arrays and act as the reference for time alignment Typically a measurement microphone is located in the overlap region of the L and LL arrays and the LL array is delayed with respect to the L array same for the RR versus the R array To geometrically improve time alignment in the overlap region between the main and offstage arrays the location of the offstage array should follow the arc of a circle with the radius of the circle at upstage center as shown in Figure 67 Note This sound design approach is similar to distributed sound reinforcement using coaxial loudspeakers i e separating V DOSC arrays in a manner so that desired audience coverage is achieved while the effects of audible interference are reduced For more details on the benefits of coaxial loudspeaker tech
201. o infill enclosures include L ACOUSTICS MTD 1 08a MTDI I2b 156 112 115 115XT loudspeakers Hybrid Stacked Flown Systems are a good solution for theatrical installations where the flown system provides balcony circle and upper balcony upper circle coverage and the stacked system provides floor orchestra level coverage Most theatres have significant vertical coverage requirements due to a relatively short throw distance of 20 35 metres combined with a high audience elevation of 12 15 metres in the upper circle In addition many theatres have rigging points with weight load restrictions that limit the number of loudspeakers that can be flown For these reasons the hybrid stacked flown sound design approach is practical in reducing the number of enclosures required and at the same time this sound design approach can help improve image localization especially with the addition of centre cluster front fill and underbalcony delay systems combined with judicious time alignment and relative level adjustment between all elements of the sound design Note For hybrid stacked flown systems the trim height of the flown system should be selected so that the bottom V DOSC cabinet has a zero degree site angle and is at the same height as the listening level for the first row of the balcony audience This helps avoid reflections from the balcony face while providing more even off axis coverage for the first row of the balcony
202. oco MM MN Spip D d a tt w Figure 96 Recommended Installation Tools L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 131 of 158 7 SPECIFICATIONS 7 1 V DOSC ENCLOSURE SPECIFICATIONS The specifications for one individual V DOSC enclosure are given below These individual enclosure specifications are not relevant to V DOSC system performance since overall system behavior is the net result of the complex acoustical coupling between all enclosures of the array Frequency response Power rating pink noise LF MF HF Horizontal Coverage Angle Vertical Coverage Angle System Data enclosure 2 enclosures 4 enclosures LF MF HF Material Finish Grill Features Dimension WxHxD 50 18k Hz 3 dB 3WX preset 40 20k Hz 10 dB Impedance 2 375 Wrms 2 1500 Wpeak 2 8 ohms 600 Wrms 2400 Wpeak 8 ohms 200 Wrms 800 Wpeak 6 ohms 90 6 dB points symmetrical about main axis 70 3 dB points symmetrical about main axis defined by the array Continuous SPL Continuous SPL flat array maximum curvature 134 dB 134 dB 140 dB 39 dB 5 degrees vertical coverage 146 dB 143 dB 15 degrees vertical coverage 2x 15 weather resistant loudspeaker 3 voice coil bass reflex 4 x 7 weather resistant loudspeaker kevlar cone bass reflex 2 x 1 4 compression driver mounted on 2 x DOSC waveguides Baltic birch plywood Sea
203. odes SPAC25 1 37 SPAC25 2 SPAC26 3 27 4 SPAC28 5 5 for use with corresponding BUMPxx CHARIOT Transportation chariot for 2 x BUMP2 2 x BUMPSUB ANGLE straps ratchet straps screwjacks shackles and other rigging accessories dV BUMP Flying bumper for rigging dV DOSC and or dV SUB When combined with V DOSC 2 can be used for rigging dV DOSC on top of V DOSC or for stacking dv DOSC dV DOWN Pair of rigging adapters for installing dV DOSC underneath V DOSC for down fill applications 5 oo ANGLE STRAPS TE BUMPDELTA x SPACER L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 24 of 158 CHARIOT dV DOWN dV BUMP Figure 10 V DOSC Rigging Accessories L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 25 of 158 SUBWOOFER ENCLOSURES 12 58218 Front loaded bass reflex dual 18 subwoofer for high level extended bandwidth Optional removable front dolly not shown recommended for touring applications 13 SUBCOV Protective cover for SB218 enclosures comes in pairs 14 dV SUB Dual vented bandpass loaded triple 15 subwoofer for high level low frequency extension Optional removable front dolly not shown recommended for touring applications 15 dV SUBCOV Protective cover for dV SUB enclosures comes in pairs 58218 SUB dVSUB COV Figure 11 V DOSC Subwoofer Options SUBWOOFER RIGGING ACCESSORIES 16 BUMPSUB Flying
204. of HF shelving equalization applied to the high section When used standalone without subwoofers two types of stereo 3 way presets are available X and INFRA There are four basic operating modes when V DOSC is used with 58218 subwoofers as a 4 way system X XAUX INFRA 4W and for extra impact dV SUB subwoofers can be added to create a 5 way system X INFRA modes A summary of operating bandwidths for the various presets is given in Table 9 Individual presets are discussed in the following section along with further details concerning LO HI equalization subwoofer time alignment techniques and sub low gain scaling procedures Table 9 SUB LOW OPERATING BANDWIDTH SUMMARY 3 WAY PRESETS PRESET V DOSC LOW 3W INFRA 60 200 Hz LF shelving eq 30 200 Hz LF shelving eq 4 WAY PRESETS x poe ooe 5 WAY PRESETS FLOWN dV SUBs PRESET 58218 dV SUB V DOSC LOW 5W INFRA 27 60 Hz 60 200 Hz 60 200 Hz LF shelving eq 27 80 Hz inverted 30 200 30 200 Hz LF shelving eq L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 52 of 158 LO HI PRESETS V DOSC presets come in pairs LO smooth HI bright and there is a 3 dB difference in HF shelving eq between LO and HI presets In addition to the HF shelving eq difference for V DOSC V7 LO presets the mid high section output gains have been scaled up by 2 dB in order to provide a flatter overall response curve for class
205. ol is an issue for example in situations where outdoor venues are located close to residential areas The accuracy flexibility and predictability inherent in the V DOSC approach to sound reinforcement has opened up many new horizons for sound design Figure 5 V DOSC Array L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 17 of 158 V DOSC TRAINING AND QUALIFICATIONS V DOSC is an innovative design based on a new approach to sound reinforcement that can provide predictable results to the extent that no other existing system can However achieving the desired result requires following a methodical procedure which may at first seem unusual to some sound designers and engineers Hopefully most of you will embrace this technology and approach V DOSC with an open mind excited by the possibilities that such a system allows However it can be hard to teach an old dog new tricks For those of you in this category the first step to take is to forget your experience with other systems and overcome your biases Try to accept the fact that THIS SYSTEM BEHAVES DIFFERENTLY Once you understand the procedures involved in working with V DOSC you will save time and more importantly obtain better more predictable results V DOSC cannot be left the hands of someone who has no experience with the system even if that person has great skills and experience with respect to other systems A V DOSC operator needs specialized training and there
206. omplete details on variable curvature array design 2 3 V DOSC COVERAGE MODELING USING ARRAY 2004 L ACOUSTICS has developed a fast easy to use prediction spreadsheet named ARRAY 2004 that operates under Microsoft Excel ARRAY 2004 can predict coverage for flat constant curvature or variable curvature V DOSC arrays The first four worksheets represent vertical cut views section elevations of the audience in the XZ plane and show a pseudo 3D representation of the intersection of the site angles for each enclosure with the audience these intersections are termed enclosure site angle impacts The direction of each enclosure is calculated according to the user input angles All angles are referenced with respect to the site angle of the top enclosure which should be aimed at the rearmost part of the audience Cutview sheets are used to shape the vertical isocontour of either V DOSC or dV DOSC arrays to match the audience area Note Cutview sheets and V ARRAY used to simulate V DOSC arrays including dV DOSC upfill and or downfill enclosures while Cutview sheets dV ARRAY dV ARRAY2 are used for dV DOSC The H ISOCONT sheet displays the horizontal isocontour see Section 2 1 of all defined arrays projected onto a plan view of the audience area in the XY plane The SUB ARC sheet is used to calculate delay taps based on the physical configuration of a given subwoofer array for electronic arc processing see Section 3
207. on the bumper Since the depth of the BUMP2 is larger than that of a single enclosure this allows for better front to rear stability for the stacked array Screwjacks can be attached at the corners of BUMP2 and used to tilt the BUMP2 and hence the whole array upwards 2 screwjacks at the front or downwards 2 screwjacks at the rear In this manner the site angle of the array can be adjusted to match coverage requirements When stacking angles between adjacent enclosures cannot be obtained by gravity and spacers are employed in addition to angle straps Alternatively rear ratchet straps can be employed to provide the correct angle between enclosures in conjunction with the angle straps NOTE For safety reasons a stacked array should not exceed more than 6 V DOSC enclosures high The DELTA PLATE rigging accessory is available to allow for pan adjustment of flown V DOSC arrays The relative action of the 2 rear motors controls the rotation of the array as shown in the figure below MOTOR 2 adt 4 BUMPER SHACKLES ier CHAIN 5 MOTOR 3 DELTA PLATE _ 16 max V DOSC BUMPER Figure 19 BUMPDELTA 1 4 58218 SUBWOOFER SPECIFICATIONS L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 35 of 158 Dimension WxHxD 300mm x 550mm x 700mm 51 2 x 21 7 x 27 6 Weight 106 kg 234 Ibs Figure 20 58218 Subwoofer Front and Rear Views With the addition of
208. ondition and the maximum angles are calculated for two minimum listener distances dm 10 or 20 metres Table 22 WST Criteria Number 5 COMPONENT Nominal Diameter Enclosure Height Max Interelement Angle Max Interelement Angle mm m degrees degrees 460 3 2 4 6 8 0 496 15 0 416 12 0 336 8 0 241 I0 m dmin 20 For front loaded 15 systems such as V DOSC it is seen that the maximum allowed angle is 4 8 degrees for dmn 10 m and 6 0 degrees for dmn 20 m This explains why the maximum ANGLE STRAP value for V DOSC is 5 5 degrees For front loaded 8 systems dV DOSC it is seen that the maximum allowed angle is degrees for dmn 10 m and 11 7 degrees for dmn 20 m Although the maximum value for dV DOSC may seem conservative at 7 5 degrees this value corresponds to a minimum listener distance of 3 metres allowing listeners to be closer to the system for downfill or shorter throw applications L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 153 of 158 APPENDIX 8 ANGLE STRAP CALIBRATION The figure below provides the information necessary to construct a fixture for calibrating angle straps Individual fly track sections can be laid out according to the indicated double stud fitting plunger plunger spacing to provide a fast test jig for checking angle strap values and labeling When testing angle straps they should fit the test jig with a tolerance variation of 1 to 2 mm Note For
209. orwards see Fig 95 v L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 115 of 158 8 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 116 of 158 o p L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 117 of 158 E ou 9s Ad gt mw A uy iis EV a rg i L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 118 of 158 bb cc dd Figure 95 Photo sequence showing the steps involved in flying V DOSC L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 119 of 158 Ratchet Strap Adjustments Before taking the system to trim raise the array above the ground to tension the rear ratchet straps See Fig 95 w x Mounting a remote digital inclinometer on the top enclosure and using a handheld digital inclinometer for the bottom enclosure is the most accurate technique for matching the actual installation to the ARRAY 2004 or SOUNDVISION simulation Essentially we want to adjust the ratchet straps so that the installed array has the correct top and bottom enclosure site angles in order to obtain the correct overall vertical coverage angle Cell P36 in ARRAY 2004 With reference to the remote inclinometer readout adjust front and rear motors to pre tilt the array so that the top enclosure is angled according to the calculated site angle 1 5 degrees for the example in Fi
210. osure to dV BUMP attachment not including dV SUB 4 a pick point calculation utility is included for single point hangs 5 angular spacing between enclosures is chosen from the following available values O 2 3 75 5 5 7 5 for dV ANGLEPI or 3 4 57 6 5 for dV ANGLEP2 Note The site angle for dV DOSC enclosure is equal to the dV BUMP site angle provided that 3 75 angle bar is used at the rear to connect enclosure 1 to the bumper The 3 75 angle should be used to attach the top dV DOSC to dV BUMP this allows a laser and or remote digital inclinometer to be mounted on the dV BUMP to measure the focus of the top enclosure dV DOSC PICK POINT UTILITY A pick point calculation utility is also included for single point dV DOSC array hangs Pick point holes are numbered 0 to 16 from front to rear on dV BUMP Hole 0 corresponds to the downstage motor point holes 1 8 correspond to pick points the central spreader bar and holes 9 16 correspond to pick points on the rear extension bar The user varies the pick point number from 0 to 16 and the bumper elevation while attempting to minimize the Site Angle Deviation wrt Target value so that this value is as close to zero as possible The user can then determine the appropriate pick point and whether the dV BUMP extension bar is required or not Note Always verify the actual obtained array tilt angle using an inclinometer during installation If a 3 75 degree angle is
211. overage combined with reduced centre build up in comparison with L R subwoofer arrays In effect LCR subwoofer arrays act as an approximation to an electronic delay processed horizontal line array of subwoofers as discussed in Section 3 5 2 Figure 78 shows a ground stacked LCR configuration In this case time alignment should be performed in multiple steps i time align L with respect to C with the measurement microphone on axis to L at a distance where the SPL from C and L arrays is identical ii time align V DOSC FOH L with respect to L with the measurement microphone located between FOH L and ground stacked L subwoofers at a distance where the SPL from the low section of the flown system equals the SPL from the ground stacked subwoofers iii duplicate the time alignment settings for R subwoofers and FOH R iv if applicable time align LL and RR to L and R respectively using a measurement location in a representative location where the coverage of the main and off stage fill systems overlap Figure 78 b shows a hybrid ground stacked LR flown C configuration In this case a stereo infill system using ARCS or dV DOSC for example can be combined with the ground stacked LR subwoofer arrays and a centre cluster fill system could be integrated with C subwoofer array Time alignment should be performed in multiple steps i time align L with respect to C with the measurement microphone in between L and C at a distance where the SPL from
212. p with main system coverage in order to optimize the transition between the main system and the delay For example main V DOSC arrays can be focused to provide coverage up to 120 metres and delay positions installed at 90 metres and focused to provide coverage from 100 150 metres 3 Time alignment of delays should be performed at a measurement point located on the axis of the delayed source and the reference source If the delay time is set so that the two sound waves arrive at the same time on axis the reference source will be slightly ahead of the delayed source at off axis locations providing proper image localization towards the stage see also 4 Over delaying up to 5 ms is acceptable due to the Haas precedence effect greater than 15 ms is not acceptable since the delayed sound will be perceived as an echo with respect to the main signal 5 For speech reinforcement it may be necessary to under delay in order to optimize the off axis intelligibility and clarity for the audience seated behind the delay system i e towards the stage 6 Time domain based measurement equipment is essential for setting delay times for example MLSSA or WinMLS Bushnell Yardage Pro rangefinder binoculars can provide a good starting point by simply measuring the distance from the delay location to the reference source Figure 87 shows an outdoor festival system example for an audience area of 150 metres deep by 200 metres wide The main L R system
213. ption and air absorption indoors resulting in spectrally balanced sound over the largest area possible This is an important benefit of V DOSC and WST since both SPL and tonal balance are more even with distance Since the flat array configuration maximizes energy and intelligibility with distance it should be used for long throw applications or in reverberant rooms It is also common to use a flat array section at the top of a variable curvature array for improved throw in arena and stadium installations In some cases the upper enclosures of flown V DOSC arrays are ratchet strapped together in order to provide such a flat long throw section Curved V DOSC Array A curved V DOSC array stacked or flown is obtained by using angle straps to provide the desired angle between enclosures To maintain the correct angles between enclosures spacer blocks can be inserted between adjacent enclosures or alternatively rear ratchet straps can be used If the angle between two adjacent V DOSC enclosures is smaller than 5 5 WST criteria are satisfied and the array behaves like a continuous curved radiating ribbon If the angle between enclosures exceeds 5 5 WST criteria are no longer valid over the entire audio frequency range Practically a larger angle produces neither desirable nor predictable results enclosures radiate individually and the benefits of collective coupling are lost this is why angle straps are available only up to 5 5 There
214. r channel assignments when powering a single V DOSC cabinet are x 16 ohms for the high frequency channel Amplifier Channel A 8 ohms for the mid frequency channel Amplifier 2 Channel 2x8 ohms for both low frequency channels Amplifiers 3 4 Channel A When powering subwoofers one 58218 is powered per amplifier channel at a 4 ohm load Multiple cabinet impedance loads and power ratings are summarized in Table 2 Fully equipped the L ACOUSTICS 24 rack contains 4 L ACOUSTICS LA48a amplifiers and can power 1 1 2 2 3 3 V DOSC 4 4 58218 subwoofers 6 6 dV DOSC 6 6 ARCS When powering V DOSC 2 enclosures in parallel is the optimum load while 3 is more cost effective Powering 3 3 V DOSC enclosures is safe for the amplifiers but does not provide the same standard of sonic quality due to reduced headroom particularly for the mid and high sections see Table 2 below Powering 4 4 V DOSC in parallel is not recommended for normal operation but it is possible to do so in emergency situations L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 38 of 158 Table 2 Load and Power Ratings for V DOSC V DOSC ENCLOSURE RATINGS LOW 8 375 1500 750 4 750 3000 1500 2 7 1125 4500 2250 2 0 1500 6000 3000 MID 8 600 2400 1200 4 1200 4800 2400 2 7 1800 7200 3600 2 0 2400 9600 4800 HIGH 16 200 800 800 8 400 1600 1600 5 3 600 2400 2400 4 0 800 3200 3200 V DOSC LOW SECTION AMPLIFIER V DOSC MID SECTION AMP
215. re 6 V DOSG Block DIagEar E 20 7 md 21 Figure 8 System Plus Offstage Fill 2 4 22 Figure 9 V DOSC system loudspeakers plus 4 4 224 244 23 Figure 10 V DOSC Rigging 25 Figure Ile V DOSC Subwoofer 26 Figure 12 Subwoofer Rigging Accessories Ree eu espe dene hs 26 Figure 13 L ACOUSTICS LA48a Power 27 Figure 14 Amplifier Rack Options and 55 5 28 Figure 5 Signal distribution and Cabling sc eeu Ul es take 30 Figure 16 Loudspeaker cabling Options wis eo edant au DR Qaid ed dM dae ae Md 32 Figure 7 V DOSC Enclosure Front and Rear 33 Figure TS BUMP PE 34 Figure T9 BUIPDEb T ap c 35 Figure 20 58218 Subwoofer Front and Rear Views 36 Figure 21 BUMPSUB 56218 Flying Bar RE 37 Figure 22 V DOSC PADO4a Amplifier Rack
216. re arrays to provide equal spacing of individual enclosure impact zones Limits exist given the vertical size of each enclosure and the relative tilt angles that are allowed between enclosures REFERENCES C Heil M Urban Sound Fields Radiated by Multiple Sound Source Arrays preprint 3269 presented at the 9274 AES Convention Vienna March 24 27 1992 M Urban C Heil P Bauman Wavefront Sculpture Technology Journal AES Vol 51 No 10 October 2003 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 147 of 158 APPENDIX 3 HOW DOES V DOSC BEHAVE WITH RESPECT WST CRITERIA The second Wavefront Sculpture Technology criterion STEP lt smallest 2 2 over the frequency range of operation is fulfilled by a V DOSC array at low and mid frequencies With reference to Figure 108 The 15 speakers are separated no more than 0 75 m and the crossover frequency is 200Hz corresponding to A 2 0 85 m The 7 speakers are separated by no more than 0 17 m and the crossover frequency is 300Hz corresponding to A 2 0 13 m max 0 75 m max 0 17 m 0 17 444 mm Figure 108 Front view V DOSC array and vertically stacked DOSC waveguides We have to fulfill the first WST criterion at higher frequencies since it is not possible to satisfy the second criteria as wavelengths are too small to have the acoustic centres of high frequency compression drivers with less than 2 2 separation
217. regions The border between CYLINDRICAL near field Fresnel and SPHERICAL far field Fraunhofer zones can be expressed as 2 elt Aborder 2 H F where H height of the array in m F frequency expressed in kilohertz extension of the cylindrical soundfield with respect to the source m In the Fresnel region the wavefront is cylindrical and expands only in the horizontal dimension nominally 90 for V DOSC The height of the wavefront is equal to the height of the array In the Fraunhofer region the wavefront is spherical and expands in both horizontal amp vertical dimensions The horizontal coverage angle is nominally 90 and the vertical coverage angle is 5 06 ae Y 3HF where D is the vertical coverage angle angle in The two following tables display data for digg with respect to the number of arrayed V DOSC enclosures L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 150 of 158 Table 20 Border in m Between Cylindrical Fresnel and Spherical Fraunhofer Zones 2 Enclosures 4 Enclosures 8 Enclosures 12 Enclosures 0 9 1 8 3 6 H 5 4m border m border m border m border m Nocylindrical 1 5 0 2 5 22 5 19 44 8 Enclosures 2 Enclosures H 3 6m H 5 4m At kHz a flat V DOSC array of 8 enclosures H 3 6 m radiates a wavefront that is cylindrical over a distance of 19 m
218. ront of the rack is 9 5 cm 3 7 in Clearance from the rear rack rail to the rear of the rack is 6 cm 2 4 in The depth from front to rear rack rails is 42 5 cm 16 7 in and the depth from front rack rail to the rear support points for the LA48a amplifier is 39 cm 15 35 in Due to the switched mode power supply technology employed in the L ACOUSTICS LA48a the rack weighs only 98 kg 216 Ibs when loaded with 4x LA48a amplifiers Using the COMB connectors located on the PADO4a amp panel the rack can be configured so that and B channels are independent Depending on how the rack is to be configured 2 WAY 3 WAY or SUB COMB connectors are selected Essentially the COMB connectors route the desired input lines from the 19 pin CA COM connector to the appropriate amplifier inputs for A and B channels respectively Using separate COMB connectors for both channels it is possible to assign the A channels B channels independently When fully loaded with 4 x LA48a plus PADO4a the 24 rack can power up to 6 x V DOSC 8 x 58218 subwoofers 12 x dV DOSC In terms of construction the amplifier rack is made of a lightweight aluminum space frame with heavy duty bracing internal shock mounting standard rack rails and provision for rear support of amplifiers Clear polycarbonate lexan front and rear doors allow the user to quickly see how racks are configured and can be conveniently stored inside the rack during use note for ventilat
219. rray Note that the displayed isocontour for each array is terminated in a line that is referenced to where coverage starts for the bottom enclosure Therefore H ISOCONT gives a direct indication as to the areas where coverage is lacking and offstage fill center fill or delay clusters are required The overlap between L R arrays illustrates which portions of the audience will experience stereo imaging Note It is not possible to simulate the transition between dV DOSC to V DOSC isocontours in ARRAY 2004 when dV DOSC is used for downfill or upfill in conjunction with V DOSC In order to simulate this transition SOUNDVISION is recommended L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 74 of 158 V DOSC ARRAY 2 WAVEFRONT SCULPTURE TECHNOLOGY PREDICTION Se ee a up _ 8 8 13 8 8 8 94 1 087 ee B 8 7 5 5 4 13 2 010 1 2 3 4 5 6 F B KION REH 15 T8 1T 181920 21 22 23 34 75 26 71 22 29 2031 22 332 334 35 13230 40412724343 45 5 47 38505157 5324 ee B5 R57 BB BO 717273 74 P5 T TT TB T DOT 82 63 24 B5 B6 BT 599 00 AUDIENCE GEOMETRY curwew _ GEOMETRIC DATA V DOSC ONLY ACOUSTICAL PREDICTION 5acbon 1 16 0 A Overal Depi of Arey dem 6 26 im 71 0 0 m
220. s also provides another level of control when dealing with over zealous guest engineers in a festival situation 5 2 MEASUREMENT PROCEDURES Tuning and equalizing V DOSC is relatively straightforward i e given the prediction tools and sound design concepts outlined in Chapters 2 and 3 the precise installation procedures described in Chapter 4 and dedicated OEM factory presets an excellent starting point for system tuning is immediately obtained upon installation Generally speaking little equalization is required and one third octave real time analysis RTA can be sufficient for measurements Alternatively MLSSA WinMLS TDS SMAART or Spectrafoo analysis can be used to obtain higher resolution and for time alignment measurements When properly installed and focussed system coverage should be very homogeneous and 3 measurement locations are sufficient for performing a systems check one in the near audience area one at the mix position and one towards the rear of the coverage pattern It should be verified that the global shape of the frequency responses at these locations is similar before proceeding to perform detailed equalization Measurement Instruments Equalization adjustments can be performed using a real time analyzer RTA however more sophisticated measurement tools such as MLSSA WinMLS TDS SMAART or SpectraFOO allow the user to obtain better results provided these instruments are properly used of course Compared
221. s will depend on throw distance and vertical coverage requirements and the guidelines outlined in multiple arrays should be followed Section 3 3 For offstage fill the same principles for flown versus stacked systems apply Section 3 2 and hybrid flown stacked offstage fill systems can also be effective In some cases a distributed approach can be adopted using tripod mounted MTD or XT coaxial enclosures to provide offstage plus rear fill coverage KUDO offstage fill V DOSC dV DOSC offstage fill Figure 85 Flown offstage fill system options As discussed in Section 3 1 stacked systems improve image localization for the audience by lowering the perceived image to stage level and geometrically a stacked system can provide more extended vertical coverage than a flown system For these reasons stacked offstage fill systems or a hybrid flown stacked approach can be of interest for arena sound reinforcement particularly for many of the newer generation basketball arenas that are narrow with high vertical coverage requirements Fewer enclosures are required to obtain the necessary audience coverage vertically and there is less audience shadowing since people are seated on a tribune gradient As an additional benefit for stacked offstage fill systems the subjective image is lowered to stage level ARCS offstage fill KUDO offstage fill Distributed XT offstage rear fill Figure 86 Stacked offstage fill system options L ACOUSTI
222. selected independently i e 4 2 format presets can also be used for aux sub drive Please refer to the preset setup sheets in Tables 11 14 when patching your signal distribution system L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 92 of 158 3 4 1 Flown V DOSC and Ground Stacked Subwoofers Subwoofers are usually ground stacked to take advantage of the 6 dB SPL enhancement that is obtained due to floor coupling effectively there is a mirror image that doubles number of subwoofers Various flown V DOSC and ground stacked subwoofer combinations are shown in Figure 69 these configurations are discussed in more detail in Subwoofer Arraying Techniques Left Right Subwoofer Configuration Central Subwoofer Line Array LCR Configuration Figure 69 Flown V DOSC and ground stacked subwoofer configurations As illustrated in Figure 70 for flown V DOSC and ground stacked subwoofer configurations time alignment of subwoofers is required due to the geometric path difference between the two systems The distance from the measurement microphone to the subwoofers is while the distance to the flown V DOSC system dyposc PATH DIFFERENCE Delaying the subwoofers by the geometric path difference is necessary to time align the subwoofers at the reference position Note The geometric path difference should be added to the pre alignment delay that already exists in the standard presets Section 1 15 for further details PATH
223. separation extended vertical pattern control is obtained at very low frequencies e Improved coupling is obtained since there is almost no discontinuity in low frequency radiation from the top of the array to the ground e This configuration is recommended for flat open air applications since extended vertical pattern control and coherent coupling provides improved throw at lower frequencies NOTE For the X preset subwoofers sound different than most sound engineers would expect due to the 27 200 Hz operating bandwidth Listening to the system band by band can be misleading however the collective performance of all speakers should produce incomparable low frequency far field projection L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 95 of 158 3 4 3 Hybrid Flown Stacked Subwoofers Flown 58218 with ground stacked centre 58218 line array Flown dV SUB with ground stacked L R 58218 arrays Figure 73 Hybrid flown stacked subwoofer configurations As seen in Figure 73 58218 or dV SUB enclosures can be flown beside L R V DOSC arrays as a low frequency extension of the system and additional ground stacked subwoofers added to provide sufficient low end impact for the first 15 20 metres As discussed in Section 3 4 2 flown subwoofers provide improved low frequency summation impact and throw along with the important benefit of improved time alignment throughout the audience Typically flown 582185 are operated in X mode while ground stacked 58
224. sing either of these programs array design can be conveniently performed and installation parameters determined on a case by case basis to optimize coverage for each venue according to the audience geometry The DOSC waveguide is registered under European patent n 0331566 and North American patent n 5163167 Please see Appendix 4 for a description of the DOSC waveguide L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 14 of 158 The configuration of transducers in V DOSC is symmetrical with respect to the plane of propagation of the radiated wavefront i e the plane bisecting the horizontal coverage angle High frequency transducers loaded by DOSC waveguides are located in the middle mid frequency transducers are on both sides of the high section and low frequency transducers are laterally positioned on both ends Such a configuration is described as having coplanar symmetry symmetry is the cylindrical domain equivalent of the coaxial arrangement for individual sound sources Essentially coplanar symmetry provides even coverage at any listening angle over a V DOSC array s 90 horizontal coverage pattern eliminating off axis cancellations and polar lobing effects at crossover frequencies Coplanar symmetry produces a stable symmetric horizontal coverage pattern allowing simple easy to use software tools to be used for horizontal coverage prediction Psychoacoustically coplanar symmetry is largely responsible for the
225. stem SPL map 1 10 83 Figure 59b Arena example plan view of 1 10 kHz SPL mappings 84 Figure 60 Illustration of Stacking Guidelines eeclesie nennen nnne 86 Figure 6l Stacked syster example i deat eie QS eq OR dde 86 Figure 62 Illustration of flying 5 87 Figure 63 Flown V DOSC SySEGET 87 Figure 64 Tradeoffs between intelligibility versus stereo imaging 89 65 ECR sees 89 Figure 66 Generic rigging plot for a V DOSC system with main L R FOH and LL RR offstage fill arrays 90 Figure 67 Rigging plot for a L R V DOSC flown 58218 system with LL RR dV DOSC offstage fill 91 Figure 68 Stereo dV DOSC offstage fill system 1 1 1 11 11 9 Figure 69 Flown V DOSC and ground stacked subwoofer configurations 93 Figure 70 Flown V DOSC and ground stacked subwoofer time 93 Figure 71 Time alignment location for flown V DOSC ground stacked L R subwoofers
226. t the A and B channel amplifier outputs to the two front panel 8 pin female CA COM connectors For the 19 CA COM connectors line is reserved for subwoofer drive lines 2 3 and 4 are for DOSC low mid and high respectively lines 5 and 6 are assigned to 2 way fill low and high respectively L ACOUSTICS cu 2 AMP PANEL FS 0 0 Fi by tt SIGNAL zv AMP 2 amp 2 C 2 SIGNAL INPUT OUTPUT SPEAKERS Figure 23 V DOSC PADO2a Amplifier Rack Panel The V DOSC PADO2a amp panel is suitable for use with 2 LA48a power amplifiers and allows for connection of loudspeakers input signal and output signal loop through The panel has a single female 8 pin CA COM connector for loudspeaker connection that is in parallel with 4 x Speakon NL4 connectors 2 x male 19 CA COM connectors for input signal connection and jumping to subsequent amp racks x 37 pin D SUB connector for COMB connector attachment that allows the user to reconfigure the amplifier rack for 2 WAY 3 WAY or SUB operating modes In 3 WAY mode V DOSC enclosures are connected via the 8 CA COM connector using DO7 or DO25 cables In SUB mode 58218 enclosures can be connected via the four individual NL4 Speakon connectors using SP7 or SP25 cables or via the 8 pin CA COM connector using DOSUB and optional DOIOP cables
227. t truck packing for a variety of trailers of standard size Enclosure weight is 108 kg 238 1 Ibs and cabinet construction consists of 15 mm 0 59 in 30 mm 1 18 in Baltic birch plywood with internal steel bracing and joints that are sealed screwed and rabbeted The finish is maroon gray high resilient paint and the front of the enclosure is protected by a black epoxy coated 1 5 mm 0 06 in thick steel grille that is covered with 10 mm 0 4 in thick acoustically transparent open cell foam Flying a V DOSC array is easy fast and secure The V DOSC enclosure features a unique rigging system where built in flying hardware extends from cabinet to cabinet to the hanging points on the 2 flying structure in a train like fashion Two recessed Aeroquip flytrack sections are mounted on both sides of the enclosure and two rear mounted rotating legs allow up to 16 V DOSC to be assembled in a vertical column Angle straps are attached between enclosures using the side flytrack sections to provide up to a maximum of 5 5 degrees between enclosures at 0 5 degree angular resolution Cabinets are physically connected while lined up on the floor and the complete array is flown all at once in comparison with other systems where cabinets are flown row by row The only external parts needed are ANGLE STRAPS and SPACER blocks these accessories are used to adjust the angle between enclosures in the array see Chapter 4 for details on flying and stacking V DO
228. the 3WX preset for V DOSC Alternatively the 58218 DELAY ARC 60 Hz preset can be used with the 3W INFRA preset subs with positive polarity 582185 are circuited in blocks of four symmetrically about the centre axis and powered by half of 24 amplifier rack The appropriate delay tap can be selected using the DSUBTK comb connector kit set of 6 COMB connectors for 6 An EXCEL spreadsheet tool to perform delay and offset calculations is available in ARRAY2004 SUB ARC Several examples are given in Figure 77 and further details on the SUBARC sheet are provided in Section 3 5 4 L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 99 of 158 HORIZONTAL 58218 16 TOTAL HORIZONTAL SB218 24 TOTAL 0 msec T2 0 761 msec T3 2 052 msec T4 3 863 msec T5 6 088 msec T6 8 634 msec 0 msec T2 167 msec T3 3 036 msec T4 5 495 msec VERTICAL 58218 8 TOTAL VERTICAL 58218 12 TOTAL 0 msec T2 0 493 msec 0 msec T3 1 282 msec T2 0 322 msec T4 2 320 msec T3 0 867 msec T4 1 632 msec T5 2 572 msec T6 3 649 msec Figure 77 Electronic delay processing examples using a 4 or 6 channel DSP 3 5 3 CONFIGURATIONS LCR subwoofer arrays are of interest for many of the same reasons as LCR V DOSC arrays see Section 3 2 2 When properly time aligned the LCR configuration can provide more even low frequency impact and horizontal c
229. this case and a rotating shackle connects the DELTA PLATE to the BUMP2 With reference to ARRAY2004 installation data the two rear motors control the height of the array and the relative action between them controls the rotation As before the front motor controls the tilt angle Use these techniques to verify L and R arrays are matched plus L L vs R R arrays if installed Rigging Amplifier Racks In some cases it is desirable to rig amplifier racks behind the V DOSC array Shorter speaker cable runs have the advantage of lower cable resistance resulting in more effective signal transfer since there is less energy dissipated as heat in the cable Reduced cable runs can also improve damping factor and potential frequency dependent losses due to the skin effect in extreme situations L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 122 of 158 SAFETY RULES CAUTION THE RIGGING SYSTEM IS RATED FOR A MAXIMUM OF 16 V DOSC 15 V DOSC 3 dV DOSC or 14 V DOSC 6 dV DOSC All rigging should be performed by certified trained personnel Proper chain motor installation and operation is absolutely necessary under all circumstances L ACOUSTICS recommends the use of safeties at all times Chain motor ratings for each fly point are as follows 0 5 motor per point for a 4 enclosure array motor per point for 5 to 0 enclosure array 2 0 motor per point for a l to l6 enclosure array For additional safety factor when flying
230. tical details L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 3 of 158 AUTHOR S NOTE Paradigm shifts don t occur very often the sound reinforcement industry especially when a small relatively unknown at the time French loudspeaker company is responsible for them Today s V DOSC is very different from the V DOSC of 1992 Constant improvements have been made to the loudspeaker itself and its components providing improved performance and durability while maintaining full backwards compatibility The latest Version 7 preset release provides smoother mid high response optimized low end and sub low processing with a simplified subwoofer time alignment procedure Better overall utilization of system power resources is the result along with increased SPL output With the V7 release many have perceived V DOSC as a new loudspeaker and with the new sub low modifications as a new system To complement the V7 preset release the number of supported DSP platforms was also increased to benefit from recent advances in DSP technology SOUNDVISION modeling software has allowed for more accurate performance prediction than ever and the introduction of new system accessories has provided added flexibility As for the rigging system this in itself was a radical innovation in its day and even now provides speed and flexibility that captive rigging systems can t equal That s what new what s old is that V DOSC remains the reference that
231. tly couple as a single extended line source Since the angle of separation between adjacent enclosures is adjustable the radiated wavefront can be focussed by physically shaping the array By satisfying WST criteria over the entire audio bandwidth the engineer or designer is provided with a single loudspeaker with well defined coverage and wavefront shape thus allowing the geometrical distribution of energy to be precisely installed to match the geometry of the audience seating area The internationally patented DOSC waveguide is the core technology V DOSC that allows the first and third WST conditions to be satisfied for frequencies higher than 3 kHz i e the wavefronts generated by individual DOSC waveguides are planar and their combined surface area accounts for at least 80 of the target radiating surface area provided the angle between adjacent enclosures is less than 5 5 degrees For traditional horn loaded systems coherent summation is not possible at higher frequencies since the wavelengths become progressively smaller than the physical separation between the acoustic centres of horn and driver assemblies Neither of the first two WST criteria can be satisfied and as a result interference occurs throughout most of the high frequency range see Appendix By comparison a V DOSC array is a full spectrum coherent loudspeaker system even for the highest frequencies As with any speaker system interference occurs however for
232. tments using the analyzer between your ears L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 128 of 158 6 MAINTENANCE AND INSTALLATION TOOLS 6 1 RECOMMENDED MAINTENANCE PROCEDURES Regular maintenance procedures monthly include component sweep using sine wave generator or other suitable test system and polarity check to ensure that all components are in good working order tighten all ANGLE strap shackles and inspect all double stud fittings cable continuity test MULTI AMP LINK CROSS LINK LINK BREAKOUT LINK EXTEND V CABLE V LINK F CABLE F LINK SUB cables clean power amplifier filters verify crossover presets are correct and up to date Periodic maintenance procedures every 6 12 months include tighten dolly locator pins and all external fasteners on V DOSC and SB218 enclosures tighten high frequency diaphragm mounting fasteners inspect all rigging components for wear and replace as necessary i e rotating legs rotating leg pins U pins rotating leg covers flytrack sections angle strap fittings inspect wiring harnesses internal connections for all panels Occasional as necessary maintenance procedures include refoam grilles repaint cabinets replace stacking runners replace protective covers for rotating legs 6 2 Recommended Maintenance Tools Miscellaneous Tools adjustable pliers rubber mallet sidecutters wire stripper soldering iron digital voltmeter breakout cables for speaker testi
233. to the SPL that would be obtained along the isocontour for each array The Console Output Signal can be increased until the amount of headroom available in the system goes to zero and the user has an indication as to the peak A weighted SPL that will be available along the isocontour Further increases in the Console Output Signal will produce a CLIP indication reflecting amplifier clip The user can also define the y coordinates for each array off center distance and the azimuth angle in degrees i e aiming or panning angle of the array Note to simulate a centre cluster simply set Y location equal to zero Optimization Procedure Typically the optimization procedure begins by using the V ARRAYI V ARRAY2 dV ARRAY or dV ARRAY2 cutview sheets to determine the number of array enclosures inter enclosure angles etc H ISOCONT is then used for adjustment of array separation and azimuth panning angles to ensure adequate audience coverage and stereo imaging at a desired A weighted SPL in order to match coverage to the audience area In some cases when horizontal coverage is an important design issue simulation can start with the H ISOCONT sheet first in order to predetermine the 0 and 45 degree axes prior to more detailed cutview simulation Output Data Output data is directly displayed as the projection of the horizontal isocontour on the defined audience area The A weighted SPL and amount of headroom in the system are given for each a
234. top rear corner of the top enclosure and the origin of the z axis is at floor level the x axis is distance or range along the desired array axis and the z axis is elevation above floor level A second cutview can also be specified at an off axis angle within the coverage pattern of the array Cutview 2 Typically the second cutview is taken at 45 offstage corresponding to the 6 dB coverage angle of V DOSC in order to confirm coverage throughout all parts of the audience The ear height relative to floor level should be entered in the listening level cell 1 2 metres for a seated audience 1 8 metres for standing Cutview Cutview 2 Plan View Section View Ac IUE 30 30 40 Figure 45 Defining Cutview Dimensions Although detailed blueprints are not necessarily required the more information that can be obtained on a venue for defining the audience geometry the better Typically plan and section views are available for most venues upon request In situations where such documentation is not available there are a number of options use a tape measure or laser range finder such as the Leica Disto Basic or Hilti PD22 on site to perform dimensional measurements Alternatively L ACOUSTICS has had good results with the Bushnell Yardage Pro 600 for field measurements Apart from being useful for defining room geometry this tool can also be used for determining delay time settings during system tuning
235. tput gains to achieve the desired tonal balance Note For larger arrays 12 16 enclosures mid and high output gains can be increased by 3 6 dB to compensate for increased low end coupling Simple attenuation is generally all that is necessary do not reach for the graphic equalizer first Keep in mind that the best frequency response is not necessarily a flat line from 20 to 20k Hz see the above discussion on tonal balance 8 Duplicate settings for the other side and verify that both sides are the same by measuring the Left and Right frequency responses at the mix position 9 Measure FOH Left or Right frequency response at a number of representative locations throughout the coverage region 9 12 measurement locations Store the results and perform a spatial average Note Be careful of wind effects and make sure that the measured HF response above 8 kHz is stable and repeatable 0 Compare all measurements to see if there is good correspondence i e system coverage is acceptable then perform system equalization based on the spatial average of all measurement locations If a given measurement location is in close agreement with the spatial average re place the microphone at this location and use this as a reference for conducting system eq Another useful approach invert the spatially averaged measurement curve then use this as a target while electrically sweeping the equalizer Alternatively sweep the system equalizer while it is i
236. used between the top dV DOSC and dV BUMP then the angle of dV BUMP corresponds to Site 1 to Next for the selected pick point For further details on modelling dV DOSC using ARRAY2004 please refer to the dV DOSC User Manual L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 72 of 158 Upstage Downstage motor motor 4 16 80 5 oe 2 9 8 Pick point hole numbers Bumper L elevation Angle 9 Site angle to next b Array height 2 dim Angle 2 to next t Site angle 2 Angle 3 to next Site angle 3 Site angle 4 Bottom element Z axis elevation height Reference origin Floor level Array depth X axis X dim range Figure 49 ARRAY 2004 Geometric Data for dV DOSC L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 73 of 158 H ISOCONT SHEET The H ISOCONT sheet is used to check horizontal coverage by mapping a projection of the horizontal isocontour of the defined V DOSC and dV DOSC arrays onto the user defined audience area By matching horizontal coverage to the audience area H ISOCONT can be used to check array placement aiming and stereo imaging as well as to determine whether offstage fill front fill or center cluster arrays are required Two audience areas can be defined and the coverage of up to four arrays displayed 4 x V DOSC 4 x dV DOSC Calculation assumpt
237. ve twists Shackles and double stud fittings are then attached every chain links with a separation of open chain links between each shackle as shown in the figure below DOUBLE STUD FITTING PLUNGER THE FIFTH TRACK HOLE FROM THE TOP 11 OPEN LINKS BETWEEN MANE BOTTOM DOUBLE STUD FITTING PLUNGER THE THIRD TRACK HOLE FROM THE BOTTOM Figure 21 BUMPSUB 58218 Flying Bar L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 37 of 158 6 POWERING V DOSC The L ACOUSTICS LA48a power amplifier is specified for use with V DOSC For full technical details please see the LA48a user manual available for download www l acoustics com A brief summary of important specifications follows INPUT SENSITIVITY 2 30 Vrms 9 5 dBu GAIN 32 dB specified amplifier gain for V DOSC Table L ACOUSTICS LA48a power amplifier ratings MLS SWITCH SETTING LOAD CONFIGURATION 5dB 4dB 2dB 16 ohms Stereo 2 channel 8 ohms Stereo 2 channel 4 ohms Stereo 2 channel 2 7 ohms Stereo 2 channel 2 ohms Stereo 2 channel When powering V DOSC two amplifier channels power the low section since 15 components are wired separately internally one channel powers the mid section and one channel powers the high section If we consider half RK124a amplifier rack loaded with 4 x LA48a amplifiers numbered 1 4 from top to bottom nominal impedance loads and amplifie
238. vely you will use V DOSC V DOSC is a complete system approach starting from the basic scientific question of how to effectively couple sound sources then including aspects of performance prediction sound design system installation rigging cabling signal distribution digital signal processing and system tuning This turnkey system approach allows for accurate and predictable results however in order to achieve the best results you need to understand the theoretical concepts behind how the system works and adopt a methodical approach to sound design and installation For these reasons specialized training is necessary to obtain the best results with the system Some people think that working with V DOSC is complicated but once you understand the procedures involved you save time and more importantly obtain better more predictable results Apart from sound quality and the system design approach there are many other benefits to V DOSC Many readers are already aware of these if not hopefully they will become apparent throughout the course of this manual WAVEFRONT SCULPTURE TECHNOLOGY FUNDAMENTALS THE SOUND REINFORCEMENT PROBLEM The first task of sound engineers and audio consultants is to design sound reinforcement systems for a given audience area Performance expectations in terms of sound quality sound pressure level SPL and coverage consistency have progressively increased over the years while at the same time the size o
239. ver the defined audience geometry SOUNDVISION features a user friendly interface with multiple toolboxes that allow for convenient entry of room and loudspeaker data while at the same time displaying coverage or mapping results along with 2D Cutview Target and Source Cutview information All toolboxes can be displayed simultaneously providing the user with a complete control interface that allows for rapid system optimization Using sophisticated modeling algorithms SOUNDVISION offers several levels of support Due to its speed and ease of use Impact mode is well suited to the needs of touring sound engineers and touring sound companies More detailed information is available in SPL Mapping mode providing an invaluable tool for the audio consultant or sound designer For the installer the physical properties provided in Mechanical Data mode provide useful practical information for fixed installation applications Impact mode coverage is based the 6 dB directivity over a 1 10 kHz operating bandwidth at 5 degree angular resolution and allows for immediate visualization of system coverage and SPL distribution Optimum SPL contours are highlighted within the displayed 6 dB coverage pattern filled circles corresponding to the 3 dB coverage pattern in order to facilitate the implementation of multiple source installations For offstage LL RR V DOSC or dV DOSC arrays or distributed sound reinforcement design using coaxial lou
240. w section have the same operating bandwidth 30 200 Hz and using identical crossover points help to avoid phase shift cancellation problems note additional equalization for the subwoofer section performed in the X preset provides an effective 120 Hz low pass filter for the subwoofers see Fig 40 Flown subwoofers Subwoofers stacked as a vertical extension Figure 72 Physically coupled subwoofer configurations Optimum coupling between subwoofer and V DOSC arrays is achieved by keeping the 58218 array physically close to the V DOSC array Two configurations are possible Fly the 58218 array on the offstage side less than 3 metres from the V DOSC array axis to axis The benefits of flown subwoofers include e Improved low frequency summation impact and throw e Improved time alignment since the physical path length difference problem of ground stacked subwoofers versus flown V DOSC is no longer an issue Overall this improves low frequency summation and coherency e Elimination of local low frequency buildup for the audience down front in the first few rows Adding several ground stacked subwoofers per side or a centre position will provide sufficient low end impact for the first 15 20 metres see Section 3 4 3 e Cleaner staging and better audience sightlines 2 Stack the SB218 array directly underneath or beside offstage the V DOSC array e When subs are stacked in a column underneath the V DOSC array with minimum physical
241. with RTA measurements improved frequency and time domain resolution can be obtained and time windowing is useful for eliminating room reflections from measurements i e in general the goal is to eq the system so that the direct sound is as flat as possible for the mid high section while obtaining the desired sub low spectral contour In addition impulse response measurements that can be performed using MLSSA WinMLS or TDS are highly recommended for time alignment of subwoofers see Section 1 15 for guidelines and time aligning delay plus fill systems in terms of accuracy and the time required for performing measurements It is often useful to perform room measurements throughout a given array s coverage region 9 12 measurement locations then perform a weighted spatial average to determine a spatially averaged response curve The spatially averaged frequency response is then inverted and used as a target for adjusting the system equalizer which is swept electronically using the measurement instrument and adjusted to meet the target curve Alternatively the system equalizer can be swept electronically while it is initally flat Multiplying the flat eq curve by the spatially averaged curve then allows you to adjust the equalizer while directly monitoring the effect on the spatially averaged response These techniques can be used for fixed installations where system equalizers are remotely located or for touring applications the advantage
242. ylindrique in English this means Cylindrical Sound Wave Generator note the V in V DOSC refers to the V shaped acoustic lens configuration employed for the mid section Essentially the DOSC waveguide permits fulfillment of the and 3 WST conditions at higher frequencies L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 13 of 158 V DOSC THE SOLUTION V DOSC is the first loudspeaker system designed based on the principles of WST and can be considered as the first modern generation line source array should be stressed that there is a big difference between a line source array such as V DOSC dV DOSC KUDO or ARCS and other line arrays on the market today Whether a line array correctly behaves as a line source array depends on the extent to which the 5 WST conditions outlined in Wavefront Sculpture Technology JAES Vol No 10 October 2003 are satisfied This may seem like semantics but there are scientific and technical reasons why V DOSC works not marketing reasons V DOSC was designed as a system consisting of identical vertically arrayed loudspeakers that satisfy WST conditions for angles of 0 to 5 5 between adjacent enclosures Individual components are physically arranged within each enclosure so as to meet WST conditions frequency band by frequency band when the enclosures are arrayed together Each enclosure radiates a flat isophase constant phase wavefront allowing the overall assembly to coheren

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