LM6 Native manual
Contents
1. Bargraph display e Universal Descriptors e Supports mono stereo and 5 1 e Presets for use in Broadcast Music Post and Film System requirements Mac Intel CPU we recommend at least 2 GHz 2 GB RAM Mac OS 10 5 Leopard or higher Pro Tools 7 0 or higher or a VST AU compatible host PC Intel compatible CPU we recommend at least 2 GHz 2 GB RAM Windows XP or higher Pro Tools 7 0 or higher or a VST compatible host Formats Mac Mac VST2 4 32 64bit VST2 4 32 64bit VST3 32 64bit VST3 32 64bit Audio Units 32 64bit Audio Units 32 64bit RTAS 32bit RTAS 32bit AAX Native 32bit AAX Native 32bit Hosts LM6 supports all major hosts including Pro Tools Logic Pro Final Cut Pro X Media Composer Nuendo Wavelab Istallation e Install iLok according to instructions found on www ilok com e Install LM6 Native following the instructions given in the installer 4 LM6 Radar Loudness Meter LM6 represents a quantum leap away from simply measuring audio level to measuring perceived loudness The old level method is responsible for unacceptable level jumps in television for music CDs getting increasingly distorted and for different audio formats and program genres becoming incompatible Pristine music tracks from the past don t co exist with new recordings TV commercials don t fit drama classical music or film and broadcast doesn t match The most fundamental audio issue of all control of loudness ever2. The LU Reference parameter affects these LM6 functions and displays 1 LU Reference sets the reference point for loudness measurements in LU If the Loudness Unit parameter is set to LU Program Loudness Sliding Loudness and Loudness Max will be shown in LU relative to LU Reference Meassurements that a on precisely on target will consequently read 0 0 LU 2 LU Reference defines the 12 o clock value of the Radar meter 23 29 17 14 LM6 Radar Loudness Meter Loudness Unit LUFS All measurements of program loudness and sliding loudness are shown in units of LUFS that is in Loudness Units on the absolute scale This is the normal setting for the Loudness Unit parameter that we recommend for most applications Loudness Range is always shown in units of LU because it is basically a measurement of range or of the distance between a high and a low loudness level LU In this setting measurements of program loudness and sliding loudness are shown in units of LU that is in Loudness Units on a relative scale The 0 LU is by definition the target loudness level such as 23 0 LUFS So by selecting LU one can immediately see if a loudness level is above the target level e g 1 2 LU or below e g 3 4 LU LM6 Radar Loudness Meter 15 Matrix Intro View Show Channel Strip Show Insert v Untitled Copy Momentary Range Radar Speed Radar Resolution EBU 9 4min 6 dBidiv
3. LM6 Radar Loudness Meter 13 Max Ldn Time Options 0 4 sec 3 sec 4 sec 5 sec or 10 sec When Loudness Max is selected in Descriptors 1 or 2 this parameter sets the window for analysis E g if 3 seconds is selected the Max Loudness for the past 6 seconds is displayed Loudness Loudness Std Options BS 1770 2 Leq K or Cnt of Grav The Program Loudness measure is always rooted in the ITU R BS 1770 loudness model This parameter sets measurement gating Note that the parameter only influences Program Loudness and not Sliding Loudness or Loudness Max BS 1770 2 This setting reflects the latest revision of ITU R BS 1770 Relative gate at 10 LU safety gate at 70 LUFS Leq K This setting reflects the original version of ITU R BS 1770 No measurement gate besides from at safety gate at 70 LUFS so the user doesn t need to precisely start and stop a measurement in order to avoid bias from complete silence Cnt of Grav The standard setting from early versions of TC radar meters Relative gate at 20 LU safety gate at 70 LUFS LU Reference Range 36 LUFS to 6 LUFS The parameter specifies the loudness level to generally aim at It affects a number of functions and displays in LM6 and must be set according to the standard you need to comply with Current broadcast standards require Target to be in the range between 26 and 20 LUFS For instance EBU R128 calls for 23 LUFS while ATSC A 85 specifies 24 LUFS
4. Low Level Below Peak Indicator Show PPM 910 1 0 dBTP Auto Pause Ldn Unit Name 22 On LUFS Log file folder dl r Library Application Support TC Elect 4 Radar Resolution Radar Speed LU Reference Descriptor 1 Descriptor 2 Sliding Loudness 6 dB div 4min 23 0 LUFS Range Program Loudn 6 sec Ver 0 8 1 beta tc electronic LM6 Momentary Range EBU 9 or EBU 18 Set range on the radar meter EBU mode meters are able to display to show two different momentary displays One with a narrow loudness range intended for normal broadcast and denoted EBU 9 and one with a wide loudness range intended for film drama and wide range music denoted EBU 18 The EBU 9 setting gives a momentary meter range from 18 to 9 LU while the EBU 18 settings gives a momentary range from 36 to 18 LU Radar Speed Radar Speed controls how long time each radar revolution takes Select from 1 minute to 24 hours You may zoom between the settings as long as the history isn t reset Pressing the Reset key resets the meter and descriptor history Radar Resolution Radar Resolution sets the difference in loudness between each concentric circle in the Radar between 3 and 12 dB Choose low numbers when targeting a platform with a low dynamic range tolerance You may zoom between the settings as long as the history isn t reset 16 LM6 Radar Loudness Meter Low Level Below Low Level Below determi
5. Reset Key Before a new measurement press the Reset key This resets the descriptors the radar and the true peak meters Run the audio and watch the radar and descriptor fields update accordingly It is normal that the descriptors wait five seconds into the program before showing the first readings while the radar updates instantly The first five seconds of a program are included in the descriptor calculations even though they are not shown instantly LM6 incorporates an intelligent gate which discriminates between foreground and background material of a program Consequently a measure doesn t start before audio has been identfied It also pauses the measurement during periods of only background noise and in the fade out of a music track Universal Descriptors and Dolby LM100 Unlike methods that measure dialog only LM6 may be used with any type of audio LM6 Radar Loudness Meter 9 which includes dialog of course If you wish to measure dialog its recommended to do a manual spot check of a program or a film Find 10 30 seconds of regular dialog and measure it with LM6 Where dialog may be soft regular or loud and shift by more than 15 dB inside a film regular dialog tends to be less ambiguous and more consistent across a program RX For compatibility with a proprietary measure such as Dolby LM100 only some FPN of these meters are updated to use ITU R BS 1770 and Leq K while others are locked at Leq
6. domestically has been known as Leq RLB Combined loudness and peak level meters exist already for instance the ones from Dorroughs but BS 1770 now offers a standardized way of measuring these parameters In 2006 ITU R Working Party 6J drafted a new loudness and peak level measure BS 1770 and the standard has subsequently come into effect It has been debated if the loudness part is robust enough because it will obviously get exploited where possible However with a variety of program material Leq RLB has been verified LM6 Radar Loudness Meter 19 in independent studies to be a relatively accurate measure and correlate well with human test panels It therefore seems justified to use Leq RLB as a baseline measure for loudness especially because room for improvement is also built into the standard The final BS 1770 standard included a multichannel annex with a revised weighting filter R2LB now known as weighting and a channel weighting scheme These two later additions have been less verified than the basic Leq RLB frequency weighting The other aspect of BS 1770 the algorithm to measure true peak is built on solid ground Inconsistent peak meter readings unexpected overloads distortion in data reduced delivery and conversion etc has been extensively described so in liaison with AES SC 02 01 an over sampled true peak level measure was included with BS 1770 In conclusion BS 1770 is an honorable attem
7. A The software version of LM100 should be 1 3 1 5 higher in order for it to comply with BS 1770 and to have its average loudness reading be compatible with Center of Gravity in LM5 or Program Loudness in LM6 Even used just on speech Leq A is not a precise approximation to perceived loudness so please update the unit to BS 1770 to obtain similar readings and predictable results To measure dialog with LM6 the same way Dolby LM100 is sometimes used solo the Center channel during a spot check to momentarily disable the channel weighting specified in BS 1770 if you re working on a 5 1 stem Universal Descriptors and AC3 Meta data The Dialnorm parameter meta data should indicate the average loudness of a program Basic dynamic range and level control that rely on this parameter may take place in the consumer s receiver Therefore its value should not be far off target or the consumer results become highly unpredictable Program Loudness in LM6 is directly compatible with Dialnorm in AC3 Most broadcast stations work with a fixed dialnorm setting for instance 23 LUFS This would be the Program Loudness target level for any program If your station is more music than speech better inter channel leveling may be obtained with dialnorm permanently set 1 or 2 LU lower than the Program Loudness target level True peak meters The peak meters of LM6 display true peak as specified in ITU R BS 1770 True peak mete
8. been applied If a journalist or video editor isn t capable of arriving at a suitable LRA he could be instructed to call an audio expert for help This may be regarded as initial production guidelines HDTV and digital radio Stay below LRA of 20 LU SDTV Stay below LRA of 12 LU Mobile TV and car radio Stay below LRA of 8 LU Remember to use LRA the other way around too If there is an ideal for a certain genre check its LRA measure and don t try go below it LRA should not be used for Limbo Allow programs or music tracks the loudness range they need but not more than they need Loudness Range may also be measured on a broadcast server to predict if a program is suitable for broadcast without further processing LRA is even a fingerprint of a program and stays the same downstream of production if no dynamics processing has been applied You may even check the number out of a consumer s set top box to verify that distribution processing and Dolby DRC has been disabled Like with Program Loudness and Loudness Max the meter should be reset before measuring LRA Prog Loudn Program Loudness returns one loudness number for an entire program film or music track Its unit is LUFS Some vendors and countries use the unit LKFS or LUFS but they are identical An absolute measure of loudness in the digital domain where the region around 0 is overly loud and not relevant for measuring anything but test signals Ex
9. is the VU meter Though developed for another era this kind of meter is arguably better at presenting an audio segment s center of gravity However a VU meter is not perceptually optimized or ideal for looking at audio with markedly different dynamic range signatures Unlike electrical level loudness is subjective and listeners weigh its most important factors SPL Frequency contents and Duration differently In search of an objective loudness measure a certain Between Listener Variability BLV and Within Listener Variability WLV must be accepted meaning that even loudness assessments by the same person are only consistent to some extent and depends on the time of day her mood etc BLV adds further to the blur when sex culture age etc are introduced as variables Because of the variations a generic loudness measure is only meaningful when it is based on large subjective reference tests and solid statistics Together with McGill University in Montreal TC Electronic has undertaken extensive loudness model investigation and evaluation The results denounce a couple of Leq measures namely A and M weighted as generic loudness measures In fact a quasi peak meter showed better judgement of loudness than Leq A or Leq M Even used just for speech Leq A is a poor pick and it performs worse on music and effects An appropriate choice for a low complexity generic measurement algorithm which works for listening levels used
10. regarded a 0 dBFS tone BS 1770 and LM6 output these results One front channel fed with a 20 dBFS 1 kHz sine tone gt Reading of 23 0 LUFS Two front channels fed with a 20 dBFS 1 kHz sine tone gt Reading of 20 0 LUFS All 5 1 channels fed with a 20 dBFS 1 kHz sine tone gt Reading of 15 4 LUFS 20 LM6 Radar Loudness Meter Display LM6 may use either the measurement unit of LU Loudness Units or LUFS Loudness Units Full Scale LU and LUFS are measurements in dB reflecting the estimated gain offset to arrive at a certain Reference Loudness LU or Maximum Loudness LUFS as defined in BS 1770 Since a common reference point for LU has not been agreed on at the time of writing LUFS or pointing specifically to the Leq R2LB weighting of BS 1770 might be favored initially to avoid ambiguous use of the term LU The effectiveness of any loudness meter depends on both the graphical appearance and dynamic behavior of its display as well as on its underlying measurement algorithms A short term loudness meter also relies on the measurement algorithm s ability to output pertinent loudness information using different analysis windows for instance 200 800 ms for running realtime updates It should be noted how the optimum size of this window varies from study to study possibly because the objective of a running display hasn t been fully agreed upon Formal evaluation of a visualization system is c
11. to navigate directly to the filder specified in the Log File Folder field LM6 Radar Loudness Meter 17 Stats Page Matrix Intro Sony C P View v Show Channel Strip Show Insert v PONE 747757 Untitied Statistics Program Loudness Loudness Max 3 sec Loudness Range True Peak Max Sliding Loudness 6 sec tc electronic The Stats page gives an overview of essential descriptors 1 Note The Reset button resets the meters and the log file 18 LM6 Radar Loudness Meter Level versus Loudness When level normalization in audio distribution is based on a peak level measure it favors low dynamic range signatures as shown in Fig 1 This is what has happened to CD Quasi peak level meters have this effect They tell little about loudness and also require a headroom in order to stay clear of distortion Using IEC 268 18 meters the headroom needed is typically 8 9 dB Sample based meters are also widely used but tell even less about loudness Max sample detection is the general rule in digital mixers The side effect of using such a simplistic measure has become clear over the last decade and CD music production stands as a monument over its deficiency In numerous TC papers it has been demonstrated how sample based peak meters require a headroom of at least 3 dB in order to prevent distortion and listener fatigue The only type of standard level instrument that does not display some sort of peak level
12. LM6 Radar Loudness Meter USER S MANUAL TC Support Interactive The TC Support Interactive website www tcelectronic com support is designed as an online support and information center At the site you can find answers to specific questions regarding TC software and hardware All known issues are stored in a database searchable by product category keywords or phrases Under the section My Stuff you can login to check the status of your questions download materials such as product manuals software updates and new presets This site has been specifically designed to meet the needs of our users We constantly update the database and you will find the site to be a huge resource of information Browse through Q amp A s and discover new aspects of your TC product If you can t find an answer online you have the option of submitting a question to our technical support staff who will then reply to you by e mail The TC Support Team is on constant alert to help you in any way they can tc electronic em Support Portal Tech Library Warranty Service Guidelines Service Partner Area we WA why NMA Support amp Community Support Portal 7 Support Portal lt co support interactive SE lt 7 r FAQ Knowledge base Drivers amp Software Product Manuals Discontinued products 7 2 a Contact Us a Product registr
13. access to the extremely informative radar display When mixing by numbers having Program Loudness as one descriptor and Sliding Loudness as the other displays simultaneous information about the full program side by side with the most recent loudness history Note 1 Because the Sliding Loudness measurement is completely un gated it may also be used to spot check sections of a program complying to raw ITU R BS 1770 and the first revision of ATSC A 85 Note 2 LM6 makes use of optimized statistics processing in order to display a sliding loudness value a prognosis as quickly as possible after a reset Loudness Max Loudness Max displays the maximum loudness registered since the meter was last reset Loudness Max is an especially useful parameter when checking and normalizing short duration programs such as promos and commercials BCAP rules from the UK is an example of using Loudness Max as an efficient instrument to reduce listener complaints regarding loud commercials While Program Loudness is adequate to normalize a consistent mix Loudness Max may be used as a second line of transparent defense against overly short and loud event Off Nothing is displayed Sliding Ldn Time Options 3 sec 6 sec 10 sec 15 sec 30 sec 1 min 2 min 4 min 8 min When Sliding Loudness is selected in Descriptors 1 or 2 this parameter sets the window for analysis E g if 6 seconds is selected the loudness range for the past 6 seconds is displayed
14. an extensive Universal Database of loudness based on ten thousands of assessments The database covers all sorts of broadcast material music commercials feature film and experimental sounds and is verified against other independent studies Dynamic Range Tolerance 0 of a typical audio consumer 24 18 Headroom peak Preferred Average Noise Floor 12 6 12 18 In Flight Entertainment 24 54 Headroom Preferred Average Noise Floor 30 Home Theatre Living Room 36 60 Peak Level Normalization Narrow Dynamic Range Loud o lt e 5 Home Theatre Living Room Bedroom 42 66 Fig 1 Left DRT for consumers under different listening situations Right Peak level normalization means that material targeted low dynamic range platforms gets loud The Universal Database is authoritative from an academic as well as a practical point of view It has been indispensable when designing the LM6 meter because it provided the missing link between short term and long term loudness and enabled the statistically founded Universal Descriptors of LM6 The chart of Dynamic Range Tolerance in Fig 1 is a side effect of the studies mentioned Consumers were found to have a distinct Dynamic Range Tolerance DRT specific to their listening environment The DRT is defined as a Preferred Ave
15. ation Warranty information lt User to user forum a Where to buy a Service quidelines y a Tech Library Certificate of conformity a Locate Service Partner i PENSA HDD MN AP NP AL LDL ON Gf www tcelectronic com BY TC ELECTRONIC A S 2012 ALL PRODUCT AND COMPANY NAMES ARE TRADEMARKS OF THEIR RESPECTIVE OWNERS ALL SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE ALL RIGHTS RESERVED TC ELECTRONIC IS A TC GROUP COMPANY LM6 NATIVE Table of Contents of Contents ieicciaccte 3 Features soarana A 4 System requirements 4 Instalati ON aa 4 MEPODUCTION aa EE 6 USE anedenke 8 Radar Pag adi on 9 Long term 9 Maim 11 11 ILOUGMESS 14 16 17 Level versus Loudness cceceececeeeeeeeeeeceeeeeaeeesaeeeaeeees 19 POSE SCM 22 LM6 Radar Loudness 3 Features e Realtime loudness meter adhering to ITU R BS 1770 2 e Loudness History Radar display e
16. erm loudness loudness history and long term statistical descriptors It may be used with mono stereo and 5 1 material for any type of program material Press the Radar key to bring up the Radar page This page will be used most of the time The basic functionality of the Radar page is shown in Fig 3 amp Matrix Intro Ce View Show Channel Strip Show Insert v ampere 47057 Untitled LUFS 00 00 00 Range Program Loudness Fig 3 Radar page features Target Loudness is displayed at 12 o clock of the outer ring and at the bold circle of the radar indicated also by the transition from green to yellow The descriptors Loudness Range and Program Loudness are the yellow numbers in the lower part of the display Press the Reset key to reset Radar and Descriptors Use Reset to clear all current meassurements and restart meter revolution from 12 o clock position The Pause function simply makes a temporary break in the metering an measumenst Press the Main key to set basic setting such as Descriptor type Loudness standard and Loudness units Press the Setup key to access Radar page settings and path for Log file Presets are handled via your host 8 LM6 Radar Loudness Meter Radar Page Current Loudness Outer Ring The outer ring of the Radar page displays Momentary loudness The 0 LU point Target Loudness is at 12 o clock and marked by the border between green and yellow while t
17. hallenging First of all one or more metrics must be defined by which the display should be evaluated The correspondence between the sound heard and the picture seen is one aspect to be evaluated Another metric could characterize the speed of reading the meter reliably In TC Electronic LM2 LM5 and LM6 short term mid term and long term of loudness measurements are tied together coherently and displayed in novel ways angular reading and radar that were preferred in its development and test phases However we remain open to suggestions for further improvement of the visualization of loudness LM6 Radar Loudness Meter 21 Post Script Control of loudness is the only audio issue that has made It to the political agenda Political regulation is currently being put into effect in Europe to prevent hearing damage and disturbances from PA systems and to avoid annoying level jumps during commercial breaks in television In Australia something similar may happen Many years of research into loudness of not only dialog but also of loudness relating to any type of audio programming has brought TC to the forefront of companies in the world to perform realtime loudness measurement and control Therefore TC has taken active part in loudness standardization efforts in Japan the United States Europe and other areas In broadcast digitization is driving the number of AV channels and platforms up while the total number of viewers remains
18. he Low Level point is marked by the border between green and blue The LU Reference parameter are found on the Setup page For instance if 0 LU is set at 22 LUFS and Low Level is set at 20 LU the color coding of Fig 3 applies You should keep the outer ring in the green area and around 12 o clock on the average Excursions into the blue or the yellow area should be balanced and not only go in one direction The numbers associated with the outer ring may be referenced at either maximum loudness LUFS selected or have a zero point set at the 12 o clock position LU selected Choose LUFS or LU at the Loudness Scale selection on the Main page depending on your preference Either way of looking at loudness is valid LUFS reading is in line with how peak level is typically measured in a digital system and compatible with Dolby AC3 and E meta data while the LU approach calls for a certain target Loudness to have been predetermined like e g a VU meter Note how LUFS in some countries is called LKFS but the two are identical reading of for instance 25 0 LUFS is precisely the same as 25 0 LKFS Long term measurements Universal descriptors may be used to make program duration measurements or you may spot check regular dialog or individual scenes as required It is recommended not to measure programs of a shorter duration than appoximately 10 seconds while the maximum duration may be 24 hours or longer
19. n 23 0 LUFS Range Program Loudn 6 sec Ver 0 8 1 beta tc electronic LM6 Descriptors Descriptors 1 amp 2 The two descriptors are displayed in lower left and right corners of the Radar page The options for each the descriptors are Range Program Loudness Sliding Loudness Loudness Max Off Range Loudness Range standardized in EBU R128 and abbreviated LRA displays the loudness range of a program a film or a music track The unit is LU which can be thought of as dB on the average LM6 Radar Loudness Meter 11 The Loudness Range descriptor quantifies the variation of the loudness measurement of a program It is based on the statistical distribution of loudness within a program thereby excluding the extremes Thus for example a single gunshot is not able to bias the LRA number EBU R128 does not specify a maximum permitted LRA R128 does however strongly encourage the use of LRA to determine if dynamic treatment of an audio signal is needed and to match the signal with the requirements of a particular transmission channel or platform Consequently if a program has LRA measured at 10 LU you would need to move the master fader 5 dB to make loudness stay generally the same over the duration of the program Not that you would want that In production Loudness Range may serve as a guide to how well balancing has been performed and if too much or too little compression has
20. nes where the shift between green and blue happens in the outer ring It indicates to the engineer that level is now at risk of being below the noise floor Peak Indicator Range 3 to 12 dBFS With the Peak indicator you set at which level the red peak indicator in the top of the meters is invoked Show PPM Options On Off If you use the Radar page as standard you may find the flickering meters visually disturbing This option allows you to turn the PPM meters on off Auto Pause On Off When on meassuring will follow the host and meassure only while the host is running Note Not all hosts supports the LM6 s Auto Pause function If LM6 is inserted in a host that does not supprt the Auto pause function the option is greyed out Loudness Unit Name Choose between LKFS and LUFS depending on preference and region LKFS is typically used in USA and LUFS is typically used in Europe LKFS refers to loudness units on an absolute scale and is equal to LUFS Log A new Log file is created every time the plug in is opened The Log file includes information such as when LM6 was opened how long LM6 time LM6 measured material since it was opened last Loudness Range and Program loudness data since last time LM6 was opened The log file is saved in the path set under Log File Folder To set the log file folder Double click in the log File Folder field and navigate using the computers Finder Explorer Reveal Press Reveal
21. pect readings of broadcast programs in the range between 28 and 20 LUFS Program Loudness is used as a production guideline for transparent normalizing of programs and commercials and to set loudness meta data in delivery if so required For delivery or transmission of AC3 format the meta data parameter dialnorm should reflect Program Loudness The easiest way to handle multiple broadcast platforms is to normalize programs at the station to a certain value thereby being 12 LM6 Radar Loudness Meter able to take advantage of the normalization benefits across platforms at the same time enabling static meta data Loudness measurements in LM6 are all rooted in ITU R BS 1770 However subtle differences exist between different regions of the world Therefore LM6 also includes the Loudness Standard parameter Be sure to set this parameter correctly for compliance in your region The Program Loudness target is more or less the same for broadcasters around the world especially when taking the measurement differences into account Target numbers range between 24 and 22 LUFS Like with Loudness Range and Loudness Max the meter should be reset before measuring Program Loudness Sliding Loudn Sliding Loudness unlike Program Loudness Loudness Range and Loudness Max is a continuously updated measure that doesn t need to be reset This type of descriptor is especially useful when mixing by numbers i e when there is no
22. pt at specifying loudness and peak level separately instead of the simplistic sample peak and mixed up measures quasi peak in use today The loudness and peak level measurement engine of LM6 follows the standard precisely Possible updates to the ITU standard may be released as LM6 updates provided that processing requirments doesn t exhaust the system Technical papers from AES SMPTE NAB and DAFX conferences with more information about loudness measurement evaluation of loudness models true peak detection consequences of 0 dBFS signals etc are available from the TC website Visit the Tech Library at www tcelectronic com techlibrary asp for details Meter Calibration Because of the frequency and channel weighting and of the way channels sum only specific tones and input channels should be used for calibration The most transparent results are obtained using a 1 kHz sine tone for calibration Other frequencies or types of signal may be used square wave noise etc but don t expect similar results The beauty of the system lies in its RMS foundation so this is a feature not an error The same feature enables the loudness measure to identify overly hot CDs or commercials and to take out of phase signals into account just as much as signals that are in phase If we stick to standard methods for measuring peak audio level in a digital system where a sine wave asynchronous of the sample rate with digital peaks at 0 dBFS is
23. r loud events yellow see Fig 2 Fig 2 nenas Color coding and target loudness for selected broadcast platforms based 42 consumer s Dynamic Range Tolerance DRT The aim is to center dynamic range 20 restriction around average loudness 24 in this case the 20 dB line thereby automatically avoiding to wash out differences between foreground and background elements of a mix 42 H Note how different the broadcast 48 requirements from those of Cinema 54 When production engineers realize the b ies they should I i BA oundaries they should generally stay 66 l within less dynamics processing is automatically needed during distribution and the requirement for maintaining time consuming meta data at a broadcast station is minimized In broadcast the goal is to use the same loudness measure for Production Ingest Linking Master Control Processing and Logging thereby ensuring better audio quality not only in DTV audio but across all broadcast platforms LM6 and TC processing can co exist with PPM meters VU meters or Dolby s LM100 meter LM6 greatly increases the usability of LM100 in production environments because it provides running status and gives a standardized and intuitive indication of both dialog and non dialog program LM6 Radar Loudness Meter 7 Basic Use LM6 makes use of a unique way of visualizing short t
24. rage window with a certain peak level Headroom above it The average sound pressure level which obviously is different from one listening condition to another has to be kept within certain boundaries in order to maintain speech intelligibility and to avoid music or effects from getting annoyingly loud or soft Audio engineers instinctively target a certain DRT profile when mixing but because level normalization in broadcast and music production is based on peak level 6 LM6 Radar Loudness Meter measures low dynamic range signatures end up the loudest as shown by the red line in Fig 1 right Audio production is therefore trapped in a downwards spiral going for ever decreasing dynamic range By now the pop music industry is right of In Flight Entertainment in the illustration LM6 offers a standardized option The visualization of loudness history and DRT in combination with long term descriptors from production onwards is a transparent and well sounding alternative to our current peak level obsession Not only for music but also in production for broadcast or film The engineer who may not be an audio expert should be able to identify and consciously work with loudness developments within the limits of a target distribution platform and with predictable results when the program is transcoded to another platform LM6 therefore color codes loudness so it s easy to identify target level green below the noisefloor level blue o
25. roughly the same On the sound production side it is therefore important that delivery criteria can be easily specified and met even by people not primarily concerned with audio Journalists musicians video editors marketing professionals etc Using only dialog based audio measurements in digital broadcast has led to ambiguous level management more level jumps between programs and extra time spent on audio production and management in general Non dialog based level jumps are currently creating havoc in digital TV and LM6 helps correct that situation The LM6 Loudness Meter can be used to control level and improve sound not only in Dolby AC3 based transmissions but also on other broadcast platforms such as analog TV mobile TV and IPTV To summarize LM6 is part of a holistic and universal approach to loudness control starting at the production or live engineer When she realizes the dynamic range at her disposal less processing is needed at later stages of a distribution chain The chain ends with the capability of quality controlling everything upstream by applying the same loudness measure for logging purposes A closed loop Welcome to a new standardized world of audio leveling Across genres across formats across the globe 22 LM6 Radar Loudness Meter tc electronic
26. rs give a better indication of headroom and risk of distortion in dowstream equipment such as sample rate converters data reduction systems and consumer electronics than digital sample meters used e g in CD mastering Note that the standard level meters in most digital workstations and mixers are only sample peak Final Cut Avid ProTools Yamaha etc and should only be used as a rough guideline of the headroom Note that the meter scale is extended above 0 dBFS Most consumer equipment distorts if you see readings above 0 It s not a problem to have true peak level going to 1 dBFS in production but legacy platforms analog NICAM etc and some data reduction codecs may distort unless true peak level is kept lower With Dolby AC3 and with low bitrate codecs 3 dBFS should be considered the limit while legacy platforms requiring emphasis may need even further restriction Like described in EBU R128 it s recommended to make full use of the headroom with true peaks going to 1 dBFS in production and to only restrict peak level further during distribution transmission 10 LM6 Radar Loudness Meter Main page amp Matrix Intro View Show Channel Strip Show Insert Bypass Compare lt gt Untitled Sliding Loudness Loudness Max 6 sec sec Loudness Std LU Reference Loudness Unit BS 1770 2 23 0 LUFS LUFS Radar Resolution Radar Speed LU Reference Descriptor 1 Descriptor 2 Sliding Loudness 6 dB div 4mi
27. y day makes millions of people adjust the volume control over and over again LM6 is part of a universal and ITU standardized loudness control concept whereby audio may easily and consistently be measured and controlled at various stages of production and distribution LM6 works coherently together with other TC equipment or with equipment of other brands adhering to the same global standard Follow the guidelines given to allow audio produced for different purposes to be mixed without low dynamic range material such as commercials or pop CD s always emerging the loudest Untitled Ce View Show Channel Strip Show insert Bypass pare 26 20 gt ase a LUFS 00 02 28 Radar Resolution Radar Speed Target Descriptor 1 Descriptor2 Sliding Ldn Time A 6dB div 4 min 23 0 LUFS Loudn Range Program Loudn 6 sec electronic 29 Q 32 Loudness meter fully compliant with R128 Loudness meter fully compliant with ATSC A 85 Loudness meter fully compliant with ITU R BS 1770 Loudness meter fully compliant with ITU R BS 1770 2 Radar meter showing Momentary and Short term loudness True peak bargraph meters Advanced Logging functionality LM6 Radar Loudness Meter 5 Introduction Since 1998 TC has performed listening tests and evaluation of loudness models and therefore holds
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