USER’S MANUAL English version LM2 STEREO LOUDNESS METER
Table Of Page Contents Head C ont ent s Ta ble O f Cont e n ts . ................................ ...... 3 In t r oduc t ion. . . . ............................................ 4 Quic k guide.. . . ............................................. 8 Oper at ing LM 2...................................... .... 10 Rear panel. . . . . ....................................... .... 12 The Dis play - H OM E p a g e . ..................... .... 13 The Dis play - H OM E p a g e . ..................... ....
Introduction The family of TC loudness and true-peak level meters represents a major improvement in how level is measured and normalization is performed in the professional audio field.
Introduction Once the relatively simple, yet accurate loudness model found by CRC had been independently verified through a number of tests, the search began for a complementary and up-to-date measurement of peak level. To this end, the Audio Engineering Society lent a helping hand. Consequently, our industry now holds a vastly improved and standardized way of measuring peak level in the digital domain. BS.
Introduction 24/7 Logging As a standard feature LM2 comes with hindsight: the radar can show the past 24 hours, but LM2 actually includes so much memory of its own that you can take a detailed look one week back in time, even if it has had no connection to a computer. Dump log files routinely to PC or Mac, import files into Excel or Numbers and create line charts for better overview.
Introduction Fig 1. Left: Peak-level-normalization results in systematic loudness differences between genres. Right: Loudness normalization is a better strategy and makes peak level vary instead. When production engineers realize the boundaries they should generally stay within, less dynamics processing is needed during distribution, and the requirement for maintaining time-consuming metadata at a broadcast station is minimized.
Quick Guide TC Electronic LM2 – Walk This Way Getting started with the LM2 Loudness and True-peak Meter. LM2 enables compliance with the latest global broadcast loudness standards straight out of the box. The ideal settings depend on your application: Production and Live Meter LM2 lets you “mix by numbers” by only looking at the numbers on its LCD display. For a detailed radar view, or to dump log files, connect a Mac or a PC via USB and run the Icon application included. 1.
Quick Guide Master Control Logging LM2 monitors loudness continuously 24/7. Dump log files to a PC or a Mac or bring up the Radar view using the Icon application. Note that a computer may monitor multiple LM2 units, and that it is not necessary to connect one, except for dumping log files every now and then. 1. Press the Recall key and use the dial to find a “Meter” preset, i.e. “EBU Mode R128” or “ATSC Mode A/85” 2. Press the Enter key to confirm recall of preset.
Operating LM2 Overview 1 - POWER key Power on/off. Press to turn the unit on. Press and hold to turn the unit off. 2 - PCMCIA Card Slot A PCMCIA card can be used for backing up settings and for system updates. LM2 handles PCMCIA cards from 512 kb to 2 MB. 3 - METERS These meters indicate the true-peak level as defined in ITU-R BS.1770-2. The range is from -60 dB to -1 dB. Meters may be switched between pre and post the true-peak limiter.
Overview Operating LM2 6 - PAUSE key 8 - SET GAIN Pauses the loudness measurements. When engaged, the Home page reads “PAUSE” in the upper right-hand corner. Additional to metering, LM2 may perform static gain offsets in order for a program to comply with a certain Target level. Once a program has been measured, press the Set Gain key to have LM2 automatically apply the static gain required to make the program arrive precisely at Target level.
Rear panel overview ...continued 17 - UTILITY 11 - EDIT key Press to enter preset Edit mode. Use the CURSOR UP/ DOWN keys to navigate and the ENCODER to change values. Press UTILITY to access the Utility page. The Utility page holds the following parameters: - Display viewing angle - Analog trim. - Auto Info on/off 12 - ENTER key ENTER is used for confirmation of various operations. 13/14 - CURSOR UP/DOWN These keys are used for navigating in menus. 15 - ENCODER The encoder is used to change values.
The Display - HOME overview page Descriptor 1 The HOME page is the default operation page and the page LM2 defaults to from several of the sub-menus, when left untouched for 30 seconds. To access the HOME page from any menu press HOME. 1 - Preset Name This is the name of the current preset. To recall presets press RECALL, scroll using the encoder and press ENTER to confirm recall. 2 + 3 - Descriptors LM2 measures Program Loudness, Loudness Range, Loudness Max and Sliding Loudness permanently.
The Display - HOME page Set Gain Reset Meter Set Gain may be used during transmission by an experienced operator, and pressed more than once. Each time Get Gain is pressed, output loudness will be re-aligned to match Target loudness. This may create level-jumps, but at a time of the operator’s choosing. Reset Meter Press both the HOME and PAUSE buttons to reset metering. The display briefly indicates reset. Pause Set Gain Press Set Gain to insert a gain offset before the loudness meter.
Overview Edit Page The Edit page is used for selecting the Loudness Descriptors shown on the Home page, measurement standard, adjustment of normalizing gain, true-peak limiting etc. Note: Edit page parameters are stored and recalled with presets.
Edit Page Descriptor 1-2 Loudn. 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 programme, thereby excluding the extremes. Thus, for example, a single gunshot is not able to bias the LRA number.
Edit Page 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 access to the extremely informative radar display.
Edit Page 3. Target defines the “12 o’clock” value of the Radar meter when LM2 is connected to a Mac or a PC running the Icon application. 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.
Edit Page Target Level in these countries is -23 LUFS or -24 LUFS, measurement gating at -10 LU. United States. Page 11 of ATSC A/85 (May 25, 2011) references ITU-R BS.1770-1, even though BS.1770-2 was in effect at that time. The same page also says that “All referenced documents are subject to revision”. The wording is ambiguous and it’s up to the reader to decide whether or not a relative gate (the difference between BS.1770-1 and BS.1770-2) is applied when measuring Program Loudness.
I/O Page The I/O page is used for selecting I/O formats, clock conditions, scaling of AD and DA converts, disabling of the Set Gain function etc. Note: I/O page parameters are stored and recalled with presets.
I/O Page Ana In FS@ This parameter sets the gain in the analog domain before the A to D converter. It optimizes the use of the converter dynamic range like optical zoom on a digital camera. For precise analog measurements, where component tolerances of individual LM2 units, cable load etc. can be taken into account, this setting may be fine-tuned on the Utility page using the Ana In Trim parameters. Ana Out FS@ This parameter sets the gain in the analog domain after the D to A converter.
Page Head Utility page The Utility pages is used for setting unit specific parameters such as display viewing angle, converter trimming etc. Note: Utility page parameters are global and not stored or recalled with presets. Navigating the Utility page - press the UTILITY key to enter the page - press CURSOR UP/DOWN keys to move cursor and use the ADJUST wheel to change parameter values - to exit the UTILITY page, press EDIT - or press I/O or EDIT keys to navigate directly to those menus.
Stats page The Stats page provides an overview of key parameters. Press the HOME key at any time to enter the Stats pages and see; Program Loudness, Loudness Max, Loudness Range and True-Peak Max.
Preset handling Page Head Preset Recall Preset Store Factory presets, User presets and PCMCIA presets may be recalled from LM2’s front panel, or using the Icon application. The User preset bank may be copied to a computer or overwritten using the Library/Bank page of the Icon application. Presets can be stored in any of the 99 user locations and presets can be named individually. Navigate using the UP/DOWN keys and the encoder.
TC Icon LM2 Page&Head All functions of LM2 work perfectly without a Mac or PC, but it may project more details on a computer display. Connect a Mac, a PC or TC Icon MKII via USB to gain access to the unique radar loudness meter. If a connection is established this way at least once per week, you may dump a detailed log covering full 24/7 operation. All parameters controllable from the front of the LM2 can of course also be set and adjusted via the TC Icon.
LM2 & TC Icon • • • Press the DETECT key. The TC Icon Editor will scan the system and find the connected units. When the connected LM2 unit is detected, assign the unit to one of the eight shortcut keys in the right side of the display, by pressing one of the eight keys. When several units are connected this page serves as a convenient organizer for the entire system.
TC Icon Store To store a preset: • • • • Select Store Rename Preset by pressing Preset Name Select location Then press STORE PRESET The preset is not stored by entering the name and pressing ENTER. To actually store a preset the STORE key must be pressed on the Store page Library Pages These are the pages from where all preset handling is controlled when using the TC Icon Editor.
TC Icon Bank Handling Via the Library Bank page it is possible to backup and retrieve the User bank either to your hard disk or to a PCMCIA card. From Bank In this area you select which LM2 preset bank you wish to copy from. From File If you have already stored banks on your computer this is where these files will appear. To Bank Select to which LM2 bank you wish to copy the selected bank to. To File Select “To File” if you wish to back-up the selected bank to your hard disk.
LM2 & TC Icon Main page The parameters on the Main page are described previously in the manual.
LM2 & TC Icon Setup page Momentary Range Sets the range of the outer ring in the Radar meter. Select between EBU +9 dB or EBU +18 dB. Radar speed Sets the duration of each radar revolution. Select from 1 minute to 24 hours. You may “zoom” between the settings, as long as the history isn’t reset. Pressing the 30 “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.
LM2 & TC Icon or changing the Time Reference, resets the meter and descriptor history. 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. Alert Indicator Range: Off/Stereo Integrity The Alert indicator is located on the Radar page and indicates suspected lack of stereo integrity based on measuring the difference of left/right outputs.
TC Icon & LM2 Stats Page The Stats page gives an overview of essential parameters. Compared to the STATS page on the LM2 front, the TC Icon Stats page also holds the Sliding Loudness parameter. Note! The Reset button resets the meters and the log file.
LM2 & TC Icon Radar Page 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, are the yellow numbers in the lower part of the display. Press RESET to reset Radar and Descriptors. The Radar page makes use of a unique way of visualizing short-term loudness, loudness history, and long-term statistical descriptors. It may be used with mono and stereo material for any type of program material.
Radar Page Meter Reset Please notice that the meter will be reset and the history/log-file is deleted in the following situations. Power on off - turning of the LM2, Either from the front or the back, will reset the meter.
Using Multiple LM2’s Up to 8 LM2’s can be conveniently controlled and monitored by a single TC Icon Editor. You can switch between and access each frame via the Select page. Log files can be stored in the same or different folders convenient tracking of each unit.
Logging 24/7 Logging Dump Log As a standard feature LM2 comes with hindsight: the radar can show the past 24 hours, but LM2 actually includes so much memory of its own that you can take a detailed look one week back in time, even if it has had no connection to a computer. Dump log files routinely to PC or Mac and design graphing showing history etc. in Excel. (see guide on the following pages). Press to dump the LOG file to the specified location.
Logging Loss of Log file - In the dialog “Open” (Ctrl+O) select “All files” in File-Types Select the LM2 log file and click “Open” Select “Delimited” - Click “Next” Select “Tab” as Delimiter and press “Next” - in Columns Data format select “General” - press “Advanced” and select “.” as Decimal separator. DO NOT SELECT “,” ! By using Microsoft Excel or Mac iWorks Numbers the history Log file can be viewed graphically.
Logging You may prefer using Excels “Line Chart” function to view and analyze the data. - Select the range Loudness Data you want to see in a Line Chart. - Now select “Insert - Line” and the type of line you want to see.
Setup Examples - Production Fig 1 Stand-alone Production meter for “mixing by numbers”. Use a preset from the Meter bank. Fig 2 Production meter extended with Radar. Use a preset from the Meter bank.
Setup Examples - Production Fig 3 Calibrated stereo listening added to metering. Use a preset from the Meter Cal. Mon. bank. Fig 4 Calibrated listening for multiple sets of speakers and headphones added to metering. Use a preset from the Meter bank.
Setup Examples - Ingest Fig 5 Meter and gain normalize for broadcast Ingest and QC. Use a preset from the Ingest bank. Fig 6 Meter, gain normalize and calibrated monitoring for broadcast Ingest and QC. Use a preset from the Ingest Cal. Mon. bank.
Setup Examples - Master Control Fig 7 Meter with logging of platform output at Master Control. Open the Icon application for a detailed Radar view covering the past 24 hours. Connect a computer once per week to dump logging file. Use a preset from the Meter bank. Fig 8 Meter, logging and precision limiting for platform output at Master Control. Open the Icon application for a detailed Radar view covering the past 24 hours. Connect a computer once per week to dump logging file.
Setup Examples - Logging Fig 9 Gather logs from strategical consumer locations post transmission and post distribution.
Signal Flow Diagram 44
Technical Specifications Digital Inputs and Outputs Connectors: Formats: Output Dither: Word Clock Input: Sample Rates: Processing Delay: Frequency Response DIO: Processing Resolution: By-pass on AES (optional): Analog Inputs Connectors: Impedance: Max. Input Level: Min. Input Level (for 0 dBFS): Sensitivity: A to D Conversion: D to Av Conversion: A to D Delay: Dynamic Range: THD: Frequency Response: Crosstalk: Analog Outputs Connectors: Impedance: Max.
