TC electronic SDN BHD LM5 User's Manual
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1. BUILT FOR PRO TOOLS iN 7 fj LF 5 LMS amp LMSD LOUDNESS RADAR METERS tc electronic TC SUPPORT INTERACTIVE The TC Support Interactive website www tcsupport tc 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 Support Home Us My Stuff Login Help Product Line 63 Category 6 Search Text optional Search Tips Product Lines Categories 1 Products v Lair Sub Categories Search B RIGHT Access Level Ph rases Poweredby GET Any v 854 Answers Found Page 1 z of 43 b 1 New When will SS3 PowerCore be ready multiple 2 New DSP usage with2. 18 LU Equals 40 LFS in this case Radar Resolution 6 dB per division True peak Indicator 6 dBFS Broadcast SD O LU Equals 20 LFS Low Level Below 12 LU Equals 32 LFS in this case Radar Resolution 6 dB per division True peak Indicator 6 dBFS Film Mix O LU Equals 24 LFS Low Level Below 24 LU Equals 48 LFS in this case Radar Resolution 10 dB per division True peak Indicator 3 dBFS Mastering Pop O LU Equals 12 LFS Low Level Below 12 LU Equals 24 LFS in this case Radar Resolution 4 dB per division True peak Indicator O dBFS Mastering Wide O LU Equals 20 LFS Low Level Below 24 LU Equals 44 LFS in this case Radar Resolution 10 dB per division True peak Indicator O dBFS Standard EBU O LU Equals 18 LFS Low Level Below 9 LU Equals 27 LFS in this case Radar Resolution 4 dB per division True peak Indicator 6 dBFS Standard NAB O LU Equals 20 LFS Low Level Below 9 LU Equals 29 LFS in this case Radar Resolution 4 dB per division True peak Indicator 6 dBFS 14 LM5 amp LM5D TDM o o To s To 68 ess TOM m E __ lt feotory default compare factory default 5 compare t c electronic t c electronic Fig 9 Examples of 5 1 movie left Matrix and stereo classical music right Bolero Both examples are shown on a 12 minute per revolution Radar with 10 dB between di
3. SS3 PowerCore VSS3 POWERCORE 3 Updated 3rd party developers making plug ins for the PowerCore platform multiple 4 PowerCore driver version 1 9 2 multiple 5 New Storing settings in Preset Direct Mode VOICELIVE Contact Details Alternatively you may contact the TC Electronic distributor in your area or write to TC ELECTRONIC A S Customer Support sindalsvej 34 Risskov DK 8240 Denmark USA TC Electronic Inc 5706 Corsa Avenue Suite 107 Westlake Village CA 91362 www tcelectronic com BY TC ELECTRONIC A S 2008 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 TABLE OF CONTENTS TABLE OF CONTENTS INTRODUCTION i224 qos n do e FERATURES edie eee oes SYSTEM REQUIREMENTS 94 2 nt en BASIC USE a a PPMLPABE es eke PREFERENCE PAGE 3 a5 uri d ded waa head PRE CETO dM qao E Red LEVEE VERSUS LOUDNESS 42144 4 2 d pb oe cm e ITU R BS 4770 PRIMER METER CALIBRATION ku zu nee gimka a ue udi Bu aui tee aereus deno eee meee PRESET MANAGEMENT NOTE LMS amp LM5D TDM 1 INTRODUCTION LM5 and LM5D Radar Loudness Meter M5 represents a quantum leap away from simply measuring audio level to measuring perceived loudness The old level me
4. 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 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 Howev
5. 1 Channels L R C Ls Rs LFE True peak Run Stop Pause epee LM pages Fig 6 PPM True peak meter features Bargraph PPM meters are shown next to the round Current Loudness display which is identical to the Outer Ring of the Radar page The True peak meters operate regardless of the status of the Run Stop Pause controls Click on the bargraphs to reset the peak history 10 LM5 amp LM5D TDM The peak meters of LM5 display true peak as specified in ITU R BS 1770 True peak meters give a better indication of headroom and risk of distortion in downstream equipment such as sample rate converters data reduction systems and consumer electronics than digital sample meters used e g in CD mastering o mz eo 8 bypass DY sese seus 0 smrore LFS LOUDNESS dB TRUE PERK t c electronic Fig 7 PPM True peak meter example showing Madonna s Hung Up Note the extreme peak level way above O dBFS which is typical of hyper compressed program This track will distort heavily when played on a consumer CD player or if it s data reduced Note that the meter scale is extended above O dBFS Most consumer equipment distorts if you see readings above O With data reduced delivery 3 dBFS should be regarded as max level without too much distortion To be on the safe side with regard to broadcast linking and transmission 6 dBFS should not be exceeded often Please remember that
6. dBFS is regarded a dBFS tone BS 1770 and 5 output these results One front channel fed with a 20 dBFS 1 kHz sine tone gt Reading of 23 0 LFS Two front channels fed with 20 dBFS 1 kHz sine tone gt Reading of 20 0 LFS All 5 1 channels fed with a 20 dBFS 1 kHz sine tone gt Reading of 15 4 LFS See Fig 4 as examples of calibration tone Radar displays DISPLAY 5 may use either the measurement unit of LU Loudness Units or LFS Loudness Full Scale LU and LFS are measurements in dB reflecting the estimated gain offset to arrive at a certain Reference Loudness LU or Maximum Loudness LFS as defined in BS 1770 Since a common reference point for LU has not been agreed on at the time of writing February 2008 LFS or LKFS 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
7. excessive peak level may generate noticeable distortion and listener fatigue When you enter the PPM page the bargraph meters show the highest peak level registered since the Radar or Peak Level history was reset LM5 amp LM5D TDM 11 PREFERENCES PAGE C 2 ms bypass TOMv mu e factory detou compare auto safe Loudness Full Scale LFS w 12 LFS 12 LU 0 0 dBFS Off Program Time 4 6 dB div t c electronic Fig 8 LM5 Prefs page Preferences may be stored as Presets thereby having suitable settings for different conditions easily at hand Loudness Scale can be set to either Loudness Units LU or Loudness Full Scale LFS Because 5 uses the BS 1770 loudness model LFS is the same as LKFS When LFS is selected the numbers of the outer ring of the Radar page shown in Fig 3 apply When LU is selected the outer ring hours are marked in LU units instead O LU Equals sets the loudness required to obtain a 12 o clock reading on the outer ring which is the same as the border between green and yellow on the Radar page O LU is the reference to aim at Low Level Below determines 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 Irue Peak Indicator sets the level at which the Peak indicator lights up OBS Indicator sets the conditions for the OBS indicator to lig
8. must meet Digidesign s system requirements for Pro Tools TDM systems 2 LM5 amp LM5D TDM Since 1998 TC has performed listening tests and evaluation of loudness models and therefore holds 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 The Universal Database is authoritative from an academic as well as a practical point of view It has been indispensable when designing the LM5 meter because it provided the missing link between short term and long term loudness and enabled the Statistically founded Universal Descriptors of LM5D 24 Dynamic Range Tolerance 0 of a typical audio consumer 18 13 Headroom 4 IIl Preferred Average 412 Noise Floor 6 In Flight Entertainment i 5 d E gt im E E s 5 ope 30 9 ul 54 p gt IN Headroom peak c mic rz MM Preferred Average 36 H NOM E 60 IIl Noise Floor EG EN Ins I E Ed ME E Peak Level Normalization 42 Narrow Dynamic Range Loud Fig 1 Left DRT for consumers under different listening situations Right Peak level normalization means that material targeted low dynamic range platforms gets lou
9. program and is directly operational If for instance a broadcast station is operated at an average loudness level of 22 LFS and a commercial has its Center of Gravity measured at 19 5 LFS the program should be attenuated by 2 5 dB before transmission for a best fit Consistency indicates the loudness variations inside a program At one extreme a steady tone displays a Consistency of 0 0 LU Broadcast programming typically comes out with a Consistency between 2 and 5 LU while classical music or a feature film can show more negative readings for instance a Consistency of 10 LU or lower The number predicts how much loudness correction in LU cut and boost is needed to have a program or music track played without frequent loudness variations Center of Gravity ranges from 80 LFS to 12 LFS while Consistency ranges from 40 to O LU Examples of typical Consistency CoG values Cinema movie 6 to 15 LU 22 to 30 LFS Classical music on CD 5 to 12 LU 15 to 30 LFS Broadcast 2 to 5 LU 18 to 24 LFS Commercials 0 5 to 2 LU 15 to 22 LFS Pre 1995 pop rock CD 1 5 to 5 LU 14 to 20 LFS Hyper compressed pop rock CD 1 to 3 LU 5 to 8 LFS Note If you re involved with music mastering please observe that you enter red light district for CoG values closer to zero than 12 LFS and that you re well inside that zone if you pass the 10 LFS mark Everything you do to make music even louder will end up getti
10. visualization system is challenging 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 LM5 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 LM5 amp LM5D TDM 19 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 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 roughl
11. d 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 Average 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 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 5 amp LM5D TDM 3 ever decreasing dynamic range By now the pop music industry is right of In Flight Entertainment in the illustration M5 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 li
12. dcast on a 4 minute per revolution Radar Medium Consistency Right Madonna s Hung Up pop on a one minute per resolution Radar High Consistency The duration of one radar revolution may be set between 1 minute and 24 hours The Radar has 3 4 6 8 10 or 12 dB between each concentric circle while the O LU point is always marked as the border between green and yellow at the bold concentric circle see Fig 3 The O LU point is set on the Prefs page typically between 12 and 24 LFS The Transport Controls lower left on the display are used to make the Radar run pause or reset Note that these controls in LM5D appear as shown in Fig 3 The OBS indicator is lit to show certain inter channel anomalies Such conditions may be defined on the Prefs page The OBS indicator would typically trigger the operator to switch to PPM page for a closer look of what s going on The Peak indicator is lit to show that at least one channel is exceeding its true peak max The threshold of the Peak Indicator is defined on the Prefs page and recalled with an 5 preset 5 amp LM5D TDM 7 Universal Descriptors LM5D only Additional to the short term loudness outer ring and loudness history radar LM5D displays long term statistical descriptors that describe an entire program film or music track Unlike concepts that measure only dialog LM5D may measure any type of audio Center of Gravity CoG indicates the average loudness of a
13. er with a variety of program material Leq RLB has been verified 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 attempt 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 LM5 follows the standard precisely Possible updates to the ITU standard may be released as LM5 updates provided that processing requirements 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 d
14. ered into a surround channel is therefore 1 5 dB higher than if the same signal was entered into a front channel The LFE channel is completely disregarded by the BS 1770 loudness measure LM5 amp LM5D TDM 17 Magnitude dB f SE S Frequency Hz 10 100 1000 10000 Fig 11 Frequency weighting used with selected Leq measures Red curve A weighting Green curve RLB weighting Blue curve R2LB weighting AKA K weighting The frequency weighting employed in the loudness part of BS 1770 is shown in fig 11 It means that you cannot perform a calibration tone sweep and expect the reading to stay the same see below 18 LM5 amp LM5D TDM 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 O
15. etection consequences of O dBFS signals etc are available from the TC website Visit the Tech Library at www tcelectronic com techlibrary asp for details 16 LM5 amp LM5D TDM ITU R BS 1770 PRIMER ITU R 5 1770 standardizes the measurement of long term loudness and of true peak level LM5 displays both parameters and additionally offers a consistent way of breaking up long term loudness into a coherent running measure of instant loudness and of loudness history A block diagram of the loudness detection part of the BS 1770 measure is shown in Fig 10 The way channels are summed means square to some extent mimic s speaker summing in a the real world Therefore BS 1770 gives a meaningful indication of loudness regardless if the input format is mono stereo or 5 1 LM5Meter Left Front Pre Filter H RLB Filter H RMS H Gain Right Front Pre Filter H RLB Filter H RMS Gain Center Pre Filter RLB Filter H RMS Gain Left Srnd Pre Filter H RLB Filter H RMS H Gain RLB Filter H RMS Gain Right Srnd Pre Filter LFE gt Not used for Loudness Calculations Fig 10 ITU R BS 1770 Loudness Measure Block Diagram Note how an extra filter has been added in front of the original RLB filter and that the LFE component is disregarded completely in the measure The three front channels L C R employ the same channel weighting while the measure is 1 5 dB more sensitive to surround channel signals The reading of a signal ent
16. ht up Turn it off if you don t want warnings 12 LM5 amp LM5D TDM Time Reference can take two values Actual Computer Time or Program Time The first is synchronized to the realtime clock of the computer the latter to when a new measure was started i e when the run key was pressed Note The meter history resets when you switch between Time Reference settings 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 X key or changing the Time Reference resets the meter and descriptor history 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 Pressing the X key or changing the Time Reference resets the meter and descriptor history LMS amp LM5D TDM 13 PRESETS The following presets have been loaded as factory defaults Factory presets all use the LFS scale Program time and 4 minutes per Radar Revolution You may store new presets with a ProTools session based on your own preferences thereby easily changing scale zoom etc 2 You may switch between presets on the without resetting the Radar Broadcast HD O LU Equals 22 LFS Low Level Below
17. is typically measured in a digital system and with Dolby 100 while the LU approach calls for a certain Target Loudness to have been predetermined like e g a VU meter o To ius Ts 68 bypass TDM compare auto safe V9 lt eotory detou compare TT eee t c electronic t c electronic Fig 4 Radar page displaying calibration tones Left meter Standard NAB preset 1 kHz stereo sine at 20 dBFS Right meter Standard EBU preset 1 kHz stereo sine at 18 dBFS 6 LM5 amp LM5D TDM LOUDNESS HISTORY RADAR The Loudness Radar shows a history of loudness over time The loudness landscape may be used to judge if loudness emphasis is put where you want it to be If dialog segments are balanced against action parts if the chorus of a song has a lift against the verse if the audience is too loud in a gameshow or maybe as a target to aim for during a live transition etc o o ef rs rue MH EIC vs ese 05 Jose m T Ta compare eeraa e enr enaa ia eure eee eee ee 085 18 t c electronic m Ttc electronic t c electronic Fig 5 Different types of program shown on the Radar Left 5 1 movie Pirates of the Caribbean on a 12 minute per revolution Radar Low Consistency Center German news broa
18. mits of a target distribution platform and with predictable results when the program is transcoded to another platform L M5 therefore color codes loudness so it s easy to identify target level green below the noisefloor level blue or loud events yellow see Fig 2 Fig 2 Color coding and target 0 dB Dynamic Range Target SMPTE loudness for selected broadcast E platforms based on a consumer s 8 Dynamic Range Tolerance DRT 12 The aim is to center dynamic range restriction around average loudness in this case the 20 dB line thereby automatically avoiding to wash out 30 differences between foreground and background elements of a mix Note how different the broadcast requirements are from those of 48 Cinema 60 Cinema 4 4 4 LEM 66 When production engineers realize the boundaries they should generally stay within less dynamics processing is automatically needed during distribution and the requirement for maintaining time consuming metadata at a broadcast station is minimized In broadcast the goal is to use the same loudness measure for Production Ingest Linking Master Control Processing Logging thereby ensuring better audio quality not only in DTV audio but across all broadcast platforms LM5 and TC processing can co exist with PPM meters VU meters or Dolby s LM100 meter LM5 greatly increases the usability of LM100 in production environments because It provides ru
19. ng counteracted in iTunes or at the broadcast station but the distortion you add to go higher will remain The same warning may be given for TV commercial production Don t aim at max values but allow Consistency to go down a bit to let the program breathe Look at the radar to put audio focus where you want it to be When loudness gets normalized that s what will give your message attention Universal Descriptors are rooted in Leq K as referenced in ITU R 5 1770 and have been designed for robustness against moderate gain offsets around normal broadcast operating levels If a program exhibits a Consistency of 3 5 LU and gain is offset by dB its Center of Gravity reading is shifted by 10 dB while Consistency remains unchanged Please find more information about Universal Descriptors in the Tech Library of the TC website Long term measurements LM5D only 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 8 LM5 amp LM5D TDM not to measure programs of a shorter duration than approximately 10 seconds while the maximum duration may be 24 hours or longer Before a new measurement press the X 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
20. nning status and gives a standardized indication of both dialog and non dialog program 4 LM5 amp LM5D TDM BASIC USE 5 makes use of a unique way of visualizing short term loudness loudness history and long term statistical descriptors LM5D only 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 probably be used most of the time The basic functionality of the Radar page is shown in Fig 3 Target Loudness 0 LU oT os mes mm EL 5 to ee OBS Indicator Peak Indicator Low Level Outer Ring Current Loudness Radar Position Radar Loudness History Loudness Scale Time Consistency Center of Gravity Auto Pause Reset pages Fig 3 Radar page features of LM5D Target Loudness is displayed at 12 o clock of the outer ring and at the bold concentric circle of the radar The Universal Descriptors Consistency and Center of Gravity LM5D only are the yellow numbers in the lower part of the display Press the X key to reset Radar and Descriptors The Transport Controls Auto Pause and Reset are used to make the radar and descriptor measurements run pause and reset When Auto is pressed run green and pause yellow follows the ProTools transports Press the PPM key to bring up the PPM page as shown in Fig 6 The PPM display is used to in
21. o obtain similar readings and predictable results To measure dialog with LM5D in ProTools the same way as Dolby LM10OO set to dialog also 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 Metadata The Dialnorm parameter in AC3 metadata 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 results become highly unpredictable Center of Gravity in LM5 is directly compatible with Dialnorm in AC3 Most broadcast stations work against a fixed dialnorm setting for instance 23 LFS This would then be the CoG value to aim a program at If the program isn t only dialog the best consumer listening results are achieved if you aim Center of Gravity somewhat higher than the actual goal For a music program for instance the aim should be approximately 3 LU higher LM5 amp LM5D TDM 9 PPM PAGE Press the PPM key to bring up the PPM display Fig 6 The PPM page is used to inspect balance between channels headroom overload of channels etc Target Loudness 0 LU ires eT O Peak Indicator True Peak Note OdBFS Round Meter Max Peak Hold Current Loudness Click to Reset 5
22. spect balance between channels overload of channels etc Press the Prefs key to bring up the Preferences display as shown in Fig 8 Note that you can zoom in time or radar resolution as long as the history is not reset For instance change between 4 min per revolution to 1 hour per revolution or 6 dB per division to 10 dB per division Presets can be stored specifying target loudness noise floor overload conditions etc 5 amp LM5D 5 RADAR PAGE Current Loudness Outer Ring The outer ring of the Radar page displays current loudness The O LU point i e Target Loudness is at 12 o clock and marked by the border between green and yellow while the Low Level point is marked by the border between green and blue The O LU Equals and Low Level Below parameters are found on Prefs page For instance if O LU is set at 20 LFS and Low Level is set at 12 LU the color coding of Fig 3 applies The user should be instructed to 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 or have a zero point set somewhere mid scale Choose LFS or LU at the Loudness Scale selection on the Prefs page depending on your preference Either way of looking at loudness is valid LFS reading is in line with how peak level
23. 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 LM5D incorporates an intelligent gate which discriminates between foreground and background material of a program Consequently a measure doesn t start before audio has been identified 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 LM5D may be used with any type of audio which includes dialog of course If you wish to measure dialog it s recommended to do a manual spot check of a program or a film Find 10 30 seconds of regular dialog and measure it with LM5D 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 Note For compatibility with a proprietary measure such as Dolby LM100 only some of these meters are updated to use ITU R BS 1770 and Leq K while others are locked at Leq A The software version of LM100 should be 1 3 1 5 or 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 Even used just on speech Leq A is not a precise approximation to perceived loudness so please update the unit to BS 1770 t
24. thod 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 every day makes millions of people adjust the volume control over and over again Mb is part of a universal and standardized loudness control concept whereby audio may easily and consistently be measured and controlled at various stages of production and distribution 5 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 FEATURES Realtime loudness meter adhering to ITU R BS 1770 Loudness History Radar display True peak Bargraph display Universal Descriptors LM5D Supports mono stereo and 5 1 Presets for use in Broadcast Music Post and Film SYSTEM REQUIREMENTS Mac OS X 10 4 or higher Windows XP Pro Tools TDM 7 2 software or higher Pro Tools HD or HD Accel hardware iLok USB key iLok com account and Internet access required for product authorization System
25. visions 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 and DAWs 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 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 LM5 amp LM5D TDM 15 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
26. y 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 LM5 helps correct that situation The M5 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 5 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 PRESET MANAGEMENT NOTE LM5 and LM5D uses the standard Pro Tools preset handling 20 LM5 amp LM5D TDM
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