Bowers & Wilkins CM1 User's Manual
Contents
1. npacking installation and aftercare Unpacking We suggest that alter unpacking your loudspeakers you retain the packing against the possibility of wishing to transport them at a later date CAUTION Take great care when removing the packing since the metal tweeter dome is easily dented and such damage is irreversible Each M1 loudspeaker carton carretas Two CM loudspeaker systernis Tao CMT grilles Twa interfaces tai CE Cc di T melon interface securing boits Ce Ty interface seating pads for furniture protection tf One copy of this instruction rr Each of the pair of CMe loudspeaker cartons contains Ca One CM1 loudspeaker system B1 One Chal grilla Ce One ntertace One Interface seating pad Ch use u anly One CME sub bass module F a an a Mm an i One base for module ta One base securing bolt hi Taro baza driver griles 1 ne accessory bag contairung tour spikes Ene fitting of these ls covered in a later sec hon and three tong metal Interface securing bolts and in one carton only l One instructior manual Installation CM1 The rear af the CM enclosure is fitted with screw terminals marked red for positive and black far ne Gate These should bo connected to your amplifier and Gutputs respectively LING 4 good quality cable Since the currents involved when playing lowed risie Can be large I5 Tecommended that the cable cross sectional area should be not less than Lemme f2. a smaller ane It follows that the Che s comparatively amall units dictated by thea restricted confines of the module need large xcursion capability im order to deliver the necessary low frequency out Infact the CMe drivers are capable ofa peak to peak excursion of as much as dumm Achieving this while marta ng correct driver Parameters necessitates the use of a magnet which is actually larger than the effective cone diameter Filter networks and protection circuits So IMmprovernentsin enclosure deshon and refinement of drive units for Concept 90 were interdependent Likewise in Orie bo maintain overall system performance the crossover fiering netar RES had ta be tully capable of meeting the very highest standards dg under the headings of distartian and linearity This demands the finest limits in quality and tolerance of components The high frequency and bassimidrange drivers are protected by an updated version of the world patented APOC circuit used so suce mmm im mar Bev mentor ICHS peers HN El A l a oa mm it op peor cm SEO ST erry Limits of this manual THis instruction manual does not seek to give a full account ofthe technology invoheted in th creation of Ba Concept 90 sya toms you are interested to pursue the study of detailed Mhasunrererte and read proof of all that is summarised here please ask your Dealer for a copy of the relevant BEW Design Story publication
3. fromm the conflicting needs af output and low frequency extension Within the restraints imposed by the very compact external dimensions that are the raison o tre of Concept A0 added wall thickness would have reduced ChAt s Internal volume unacceptably corventianal construction materials called far wall thickness of 15 to 18mm Not for the first time BSW engineers Sought a new material and finally chose a fibre reinforced polymeric board This allows a considerable reduction in wall thickness therefore a valuable gain in internal volume t tool this major advance combined with all BG s computer optimisation expertise to produce in Chii a system whose bass output so balles ts diminutive size You will find that this is a system of true monitor quality capable of surprisingly high sound la els Also thanks to its Wide and balanced frequency response your Concept 90 CM1 Will faithfully reproduce even the most delicate nuances of solo instrumentalists Overall it responds splendidly to the Wide dynamic range of today s compact disc players Just as s designed to do CM2 extended bass higher power capacity In Concept 90 we have not overlooked the requirements af those auciophiles whose Interests demand further extension of bass response and greater power handling capacity For them we have produced E Concept S in its CME form which provides an extra octave and a half of low frequency extension beyond that of the CM Consegquen
4. success of the Matrix series and with Concept 90 s basic requirement of compactness always in mind the B amp W design team seized the opportunity to take Matrix construction one important step further by moulding the CA enclosure and matrix in one piece using glass fibre reinforced polyester a material that is both acoustically desirable and axceptionally rigid This new construction permits enclosure wall thickness tobe reduced from the usual Simm to any 5rrrrt thus allowing a gain of 4656 internal volume with a consequent extension of the low frequencies by about one third of anoctave To this advantage one must add the acknowledged benefits of Matrix construction a Significant reduction of those unvanted colourations 0 frequently associated with box type loudspeakers Any radiation from an enclosure adds its own character to the desirable neutral uncoloured sound produced by the drive units Reduction of the decay time of enclosure vibrations With CoOnsequent improvement in transiant response m hey factor in correct reproduction of compact discs Improved detail and depth in the stereo image due to reduction of image contusing rear and sideways radiation The sounds seem to be im the space around and between the speakers not emanating from them tha CJ The enclosure CM2 Because the columnar sub bass module ofthe CME is small and not required to reproduce anything above 150 Fz it Inter porites semi Matrix c
5. your loudspoakers within the available environment will have a greater effect than ary other variable under your contro The CMI system is designed to fit into as many different mituatiois as possible t will Function successfully on shelves furniture or stands with or without the interface fitted Hevrever the height should if possible be adjusted to keep the top of the enctosure 900 ta 1100mm from the floor Asa floor standing system the CME places the drivers at the correct height in relation to most seating arrangements E mplifier control unit and source equipment The recommended limits of RMS power output for the driving amplifier are cht en we SOW min LEO max ME sirikpika piniienn SALI BOCA rie into 451 Amplifier power output cannot be quoted precisely as it depends to some extent on the type of music being reproduced room volume and the sound level required by tha listener itis generally true to say that too high a power output is better than tee low because it allows more headroom for transients and reduces the risk of clipping with its attendant sharp rise In distortian B amp W established their own electronics research department forthe express purpose of in depth research into active loudspeakers protection amplifiers test equipment and other aspects of electronics A range of electronics specifically designed to complement the performance of your loudspeakers willbe on the market shartht We
6. Instruction Manual U i hu I Tell Nl I CM2 ntroducing B amp W Concept 90 Design Philosophy Music lovers are as likely as anyone else to live in smalilah houses or flats and probably rather mora likely to have an appreciation of good design Hitherto such limited living apace hasimposed frustrating restrictions on the enjoyment of recorded music because until mow it has been virtually Impossible to recreate full accurate sound without installing lpudspeakers of Unacceptable size This challenging question of haw te get the musical quart inte the domestic pint pot has oncupied BEW for some Years In fact the basic design philosophy for Concept 90 was conceived back in 1984 when designer Kenneth Grange presented his ideas for a small elegant enclosure totally at home in such limited roomscapes as the small sitting room study dining area or studio apartment Thanks to the ingenuity of the B amp W design team that concept is now an exciting reality in which you will share through your purchase ofa BAW Concept su system B amp W Matrix Construction The MW in the model name CMI indicates that the boud Speakers are of B amp W Matrix construction incorporating the recent invention that eliminates unwanted cabinet vibrations and brings you all the advantages of low enclosure radiation Although small dimensions bring real advantages in the middie and high frequencies problems arise
7. avold getting polish an the grilles The grilles may be cleaned remove them first by brushing with a soft clean clothes brush or something similar Please avoid touching the drive units especially the dome tweeter otherwise damage could result ja he listening room and positioning a a su SS your loudspeakers The degree of accuracy with which the original musical Bertonmance can be reproduced in your avn homo depends on a number of factors including the quality of the original recording the equipment used for reproduction and the Scousthe properties of your staning room Regardless of other links in the chain the listening ream Will to a greeter or lessor degree imprint its character onthe reproduced sound you hear in simple proof of this statement notce how the sound of the human valce changes according ta acviranment Choice of listening room Few people are fortunate enough to havea choice of listening rooms but for those to whom this is possible or anyone Planning a new home the following may be helpful guidelines Ca Any am with different dimensions for coiling height length and width will sound more even in responsa than roams where all three dimensions are similar Solid walls ar preferable and will show better repro auction of low frequency transients than some modern EBriwtriactlorts where the inner wals are of plasterboard and therafare slightly flexible Other than in howses with solid or co
8. differences certainly oxiet betwen them Wie suggest therefore that youchoose one of the better cables for this purpose after consideration ofthe published reports With your CMCM sy sberm you vill find that you are noticeably nearer to born bo the music rather than to the Iid speakers vou will hear desirable ambience and detail in good recordings unfortunately the faults in poor recordings will also be revealed We hove produced a special compact disc recording that Willonable you ta enjoy a ull appreciation of your new S EBTTT lt is avallable from your Dealer BEA Jabel No BHUVDDI BSW Present The Academy of Ancient Music Christopher Hence
9. ent boiefy on W accessories associated with loudspeakers spikes and cables Fitting spikes t your CME sub bass module is simply a matter of unscrewing the small plastic domes already fitted ta the base and screwing the spikes mite the threaded sockets revealed Spikes two sets of which are supplied with your loci can assist sound reproduction in two quite diftarent ways Firstiy due to their extremely small area of contact relative to the loudspeaker base their intertace provides many thousands of times greatar pressure at the pont of canteact This increases the stability of the loudspeaker and helps withstand any movement of the enclosure from sound xcitathor The second way li vvhich spikes can assistis by reducing the area of coupling between foor and pudspeaker enclosure This is especially Valuable in the case of a resonant floor which may be regarded as a giant sounding board coupled to the loudspeaker enclosure Twa areas of Improvement Insound reproduction will be noticed when spikes are fitted Bass transients will Improve and stereo images will be slightiy more precise due to the increased stability of the loudspeaker The subject of cables between the power amplifier and loucispeakers is dealt with under Section 3 installation There remains the question of interconnecting cables between the Various pieces of PCL TEE and the poveer amplifier A number of excellent interconnect cables are available on the market and audible
10. h the sub bass module upright position the interface by locating the five feet with the corresponding grommets Inthe module ton Position the metal plate and firmly rima down with the securing bolts E1 Fit the Chii enclosure to the interface as described earlier Fig 13 Connect the lead from the module top to the Chii enclosure with the white costed cable to the positive red terminal Finally fit the CMI1 grille by pushing firmly over the front casting Fit the sub bass module driver grilles by pressing the ping at the top and bottom of each grille inte the driver chassis grammets Canneaction ta the amplifier should be made ng outlined inthe Ch installation section using the scrme terminals at the base of the module 2 33 4 Aftercare With the CM enclosures high gloss finish the greatest care should be taken to ensure that any cleaning is done without the use of abrasive materials A soft damp clath should be all thatismecessary to clean the paintwork Proprietary polishes suth as car polish are not recommended Itis important to note that if the white finish is exposed to oxcessive sunlight the surface can discolour The sub bass module finish in semi gloss paint should follow the same cleaning procedures as recommended for the CM The real wood veneer finishes should bao treated inthe Same way A You would treat any normal piece of furniture you use an aerosol please spray onto a piece of cloth first in order to
11. ncrete floor Structures a ground floor room is preferable to an upper floor tb tc Changing listening room acoustics Quite small changes in the furnishing of a room can change its acoustic properties quite significantly If you already have pictures on the wall remove these experimentally and at once you will notice a considerable change in the sound from your loudspeakers We are not suggesting that you should awe the room bare of pictures quite the reverse bocause pictures break up the othenvise plain wall surfaces add generally give fewer discreto high frequency resonances or flutter echoes Curtains are another element which can change the Sound of your listening room in the midiupper frequencies Heavier curtains give more sound absorption of these frequencies and softer less rverberant quality to the upper octem Conversely if your room sounds too dead thinner curtains will give more life or sparkle in these frequency regions So far as sound in the low frequencies is concerned this is langely controlled by the dimensions and construction of the room However large items of furniture do change room behaviour at lor frequerncios soit may be worth ox perimenting with their placement Placement of loudspeakers There is some truth in the notion that cheap loudspeakers correctly placed may sound better than more pensive ones poorly placed While this is a somewhat simplistic idea it is certainly true that the position of
12. onstruction le the spacing within the rriatrix reinforcement is greater than usual This hes proved more than adequate to ensure that unwanted enclosure radiation ts Kpt toa very low level indeed The M2 employs reflex loading of the drivers Computer mecelling ensures optimisation of output and bass extension The drive units CM1 Reducing enclosure radiation to such extremely low lewels can give rise to an unfortunate side effect the exposure of hitherto inaudible defects in driver performance It was therefore necessary to carry through a programmes of driver development refining unit performances to mest the exacting demands of the mew Matrix technology The resulting bass midrange driver has a cone of woven Hewlar similar to that used in the renowned BEW studio TITLE E The high frequency transducer ts of entirely now design incorporating a metel darmed diaphragm lt exhibits perfect piston like behaviour up ta frequencies well beyond audibility This unitis the result of advanced research using established Be laser techniques pis the new science of finte elament AA SIS Which Can predict drvar pertarmMmance permitting Many more options to be assessed than iieach had to be built and tested The drive units CM2 Driver design for the CME sub bass module posed m quite different probier To achieve a grein bow frequency layne a on ver must move a certain voume oT air thus a lange driwer cone mees a shorter distance than
13. or nines up te A metres and correspondingly larger for longar runs TAg use of the interface supplied with your Chal is Optional t may be used where for exame a Sheil is tor ine for correct positioning However its use is definitely recommended where the loudspeaker is sited on a solid object Te fit the interface first rameve the black ore from the enclosure underside Retain the screw ehould you wish ta use the CM without the interface later Position the CM on the interface Fig 13 and fix with the securing bolt A Fit the interface seating pad and finally fit the grille by pushing tinny aver the front casting of the CML A amall gap should rernm Sin betwen the drille moulding and the enclosure ries CML INTERFACE SECURING BOLT Aj SEATING PAD CM use only SECURING BOLTS INTERFACE LOCATION _ GROMMETS SECURING BOLT A SUB BASS MODULE SECURING BOLT El s Installation CM2 The CMe is a floor standing system so no other stands are required Installation simply involves fitting the module base interface and CM enclosure together Fig El 1 Fitthe base to the sub bass module having first removed the bolt already screwed into the module Position the base note that the hole is offset to the driver side of the module replace the bolt and firmly tighten Ej Remove the twonuts and bolts securing the metal plate te the interface and retain for possible future use Wit
14. suggest you ask your Dealer fora comparative demonstration of these Products The control unit Although it deals with comparatively small voltages the control unit is a critical part of the listening chain Choose with care in the kneawloedge that the ultimate test for audi Components is critical listening At BEW s research department there are many different combinations of control units amplifiers and source components such as analogue CD players tuners etc It is our experiance that each unit to say nothing of the inber connecting cable is a variable and the final listening chainis acombination of variables which should be carefully listened to before making a final choice CD player analogue turntable and tuner The comments in the previous paragraph apply equally ta these items of equipment CO players have now been on the market for some years and already considerable advances have been made In its present state of development the CD player when coupled with the best recordings made on this medium can provide the most exceptional source material totally worthy of the finest equipment with which lt is associated he APOC protection circuit The CM system is fully protected against excessive signal levels AS soon asthe safe limit ofar drive unit is approached the protection circuit vill disconnect the Input until the fault tzvearlcieirf is nemo oudspeaker accessories Here we comm
15. ti model Ch faithfully recreates the sound of double bass bass drum and the organists deepest notes in all their full weight and splendour This generout extension in bass response and increase Inpower handling were achieved within the Concept So design Philosophy of acoustic performance uncompremised by anclosiuire elegance lt was done by designing the CME bass unite bo the back of the enclosure Because of the low crossover frequency usedi this configuration inno way impairs performance and it results in a desirably omnidirectional Pattern of sound radiation Getting the best from your system The purpose of this manual is to enhance your enjoyment of the Concept S loudspeakers you have chosen 4 system of this high class is still dependent onthe signals fed into lt and is also influenced hy the immediate environment in which it operates Useful adyice on these aspects willbe found in the following pages An international network of carefully chosen Distributors handles B amp W products in more than forty countries worldwide lf at any time you have a problem that your Dealer cannot resolve the BBW Distributor for your area will be more than willing te help Thank you for the confidence you have shown in purchasing your Concept 90 loudspenhkers Please be assured of Gur continuing interest in your long term listening pleasure BW Concept 90 design background The enclosure CM1 Following the development and worldwide
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