LoudLAB Meters



LoudLAB Meters

Ballistics Section

The last section on the navigation bar (ToolBox), the ballistics, gives access to the Loudness Meters, the Goniometer and displays the current values for: Integrated (or Programme) Loudness, LRA (Loudness Range), maximum loudness and maximum True-Peak values.

If the reader is familiar with the loudness standards, please jump to "Loudness and LRA Meters", if not, we advise the reading of "Loudness Standards" and the referred documents for the geographical location of interest.



Loudness Standards



ITU BS.1770-3

The ITU BS.1770 is the most important standard as many other standards are based on it.

The ITU standard concerns Loudness and True-peak Level. The loudness part is based on an Leq measurement (K-weighting), which is a frequency weighting developed by the Communications Research Centre (a federal research institute in Ottawa, Canada).

The True-peak standard was specified by AES SC-02-01.

The standards: ATSC A/85 (the US), EBU R128 (Europe), OP-59 (Australia) and TR-B32 (Japan), are based on the ITU standard.

ITU BS.1770 published 2006 (Geneve).

ITU BS.1770-2 published March 2011 (Geneve).

ITU BS.1770-3 published August 2012 (Geneve).



EBU R128

The "P/LOUD" group, part of The European Broadcasting Union (EBU), defined the R128 standard based on ITU BS.1770.

The R128 standard builds on 4 tech documents: EBU Tech 3341, EBU Tech 3342, EBU Tech 3343 and EBU Tech 3344.

The recommended loudness target is -23 LUFS/LKFS.



ATSC A/85

ATSC A/85 was specified by The Advanced Television Systems Committee in 2009 and applies to US broadcast digital television. A/85 is rooted in the ITU-R BS.1770 Loudness and True-peak level standard.

A/85 includes information about calibrated monitoring environments and unlike EBU R128, A/85 is only focused on the digital television.

Loudness normalisation target of -23 LKFS.

From March 2013, the A/85 recommended practice prescribes ITU BS.1770-3 for all programming.



TR-B32

TR-B32 is a Japanese standard that builds on ITU BS.1770-2 (gate is employed), however, the target level is -24 LUFS/LKFS as opposed to the -23 LUFS/LKFS.



OP-59

Operational practice by FreeTV, Australia. OP-59 is rooted in BS.1770 Loudness and True-peak level.

All short form programs should be measured using the universal (full mix) method.



Did you know?

As a rule of thumb, a gated measurement of -23 LUFS/LKFS equals an un-gated measurement of -24 LUFS/LKFS!



Loudness and LRA Meters

LoudLAB Loudness Meters



The Loudness and LRA section provides control and plots for real-time loudness and true-peak metering of the output signal.

Meters List:

Momentary Loudness (400ms window), Short-Term Loudness (3000ms window), Integrated Loudness (also known as Programme Loudness), LRA (Loudness Range) and True-Peak.

We can control the long-term meters (Integrated and LRA) with the "Start", "Stop" and "Reset" buttons below the Integrated and LRA displays. When pressed, the "Start" button will tell LoudLAB to begin or resume the metering process, while the "Stop" will pause the current metering calculations. To clear the meters we press "Reset", which can be done at any point. If "Start" is selected, the "Reset" action will clear the meters and start a new calculation, if "Stop" is selected it will clear the member meters and get LoudLAB ready for the "Start" action.

To clear the Maximum Loudness and Maximum True-peak found, we press the "Reset" button on the Momentary, Short-Term and True-Peak meters (right-hand side graph).

Parameters:

Modes: "ITU-R BS.1770-3", EBU R 128 (G10 gate)", "ATSC A/85:2013", "TR-B32", "OP-59" and Relative Gate Off

Meter Scales: "ITU Full Scale", "EBU Full Scale", "-24 Target +9 Scale", "-24 Target +18 Scale", "-23 Target +9 Scale" and "-23 Target +18 Scale".



Goniometer and Phase

LoudLAB Goniometer LoudLAB Goniometer + Phase



The Goniometer Window provides visualisation for stereo positioning and correlation.

Meters List:

Goniometer (left picture) and Goniometer+Phase (right picture).

The Goniometer represent the signal in a Cartesian Coordinate System, where the mid and side contents of the signal configure the y and x axis of the graph.

The Goniometer+Phase meter plots both stereo positioning and phase correlation. The top half of the graph represents phase and the bottom the anti-phase. Note that stereo signals will always have anti-phase content, while mono signals will not.



Loudness Distribution

LoudLAB Loudness Distribution Graphs



Even if the Loudness Leveller is not in use (see ToolBox), pressing "Plot Loudness" will make LoudLAB calculate the Loudness Distribution for the loaded file.



Peak and RMS Meters

LoudLAB Peak and RMS Meters



Bus section (see ToolBox):

The Peak+RMS meters (green -> peak || blue -> RMS) on the right-hand side, display amplitude information for both the Mid/Side and Left/Right signals.

The red dots represent the maximum amplitude (dBFS) found since the last "reset", which can be performed at any time by pressing the reset button.





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