LM6/LM2 Radar Loudness Meter User’s manual
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Table of Contents Features.............................................................................. 4 System requirements............................................................ 4 Installation.......................................................................... 4 Introduction......................................................................... 6 Basic Use............................................................................ 8 Radar Page................................................
Features • • • • • • Realtime loudness meter adhering to ITU-R BS.1770-2 Loudness History Radar display. True-peak Bargraph display. Universal Descriptors Supports mono, stereo and 5.1 (LM6 only) 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.
- Loudness meter fully compliant with EBU 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 only) LM6 - Radar Loudness Meter / 5 EN LM6/LM2 represents a quantum leap away from simply measuring audio level to measuring perceived loudness.
Introduction 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. Fig 1.
LM6/LM2 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.
Basic Use LM6/LM2 makes use of a unique way of visualizing short-term loudness, loudness history, and long-term statistical descriptors. It may be used with mono, stereo and 5.1 (LM6 only) 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.
Radar Page The outer ring of the Radar page displays Momentary loudness. The 0 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 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.
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 LM6/LM2. 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. For compatibility with a proprietary measure such as Dolby LM100, only some of these meters are updated to use ITU-R BS.
EN Main page Descriptors Descriptors 1 & 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”.
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.
Loudness measurements in LM6/LM2 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.
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.
LUFS/LKFS All measurements of program loudness and sliding loudness are shown in units of LUFS/LKFS, 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.
Setup 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.
Low Level Below EN 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. 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.
Stats Page The Stats page gives an overview of essential descriptors. Note! The Reset button resets the meters and the log file.
Level versus Loudness 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.
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 “K” weighting - and a channel weighting scheme. These two later additions have been less verified than the basic Leq(RLB) frequency weighting.
LM6/LM2 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 “LKFS”, pointing specifically to the Leq(R2LB) weighting of BS.1770), might be favored initially to avoid ambiguous use of the term LU.
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.
