Loudness Control

Overview

The Loudness Control module adjusts the gain of the signal in order to meet the specified loudness standard, such as BS.1770. Unlike the Leveler module, the gain in the Loudness Control module stays fixed in time. However a post-limiter will be applied to the signal, if it is required to meet the True peak specification.

Controls

Loudness Control module interface

Integrated loudness

Sets the desired integrated loudness of the clip, in LKFS (which is the same as LUFS).

Tolerance

Sets the +/- margin of error for the integrated loudness, in LU (loudness units). Each standard determines the tolerance, which is typically set between 0.5 - 2.

Short-term/Momentary Loudness

Short term loudness is calculated over a moving window of 3 seconds. Some loudness standards like EBU R128 s1 Short Term define a maximum short-term value. Momentary loudness is calculated over a moving window of 400ms. The Short-term/Momentary power button enables or disables this processing, and the drop-down allows you to choose between short term or momentary loudness.

True peak

Sets the maximum true peak value allowed in a clip.

Program loudness gate

When computing Integrated loudness, certain low-level signals are excluded from the computation in order to only measure the loudness of “typical” signal levels. This is called gating and is a part of the BS.1770-2, 3 standards (and also R128). Firstly, all signals with a Momentary loudness below −70 LKFS are excluded, so that the noise floor in pauses does not bias the computed loudness. Secondly, all signals with a lower Momentary loudness than 10 dB (or LU) below the average Momentary loudness are also excluded. This allows the computation of the Integrated loudness only from the typical and loudest parts of the program, while excluding silence and quieter parts, which have less effect on the listener’s impression of overall loudness of the program . Most of the loudness standards shipping with RX Loudness Control use gating, an exception being BS.1770-1. This parameter allows you to toggle gating on or off, if you’re working to a unique requirement.

Workflow

To use the Loudness Control module:

  1. Make a selection in your file. If you want to apply Loudness Control to the entire clip, use ctrl/cmd + A or click Edit > Select All.
  2. Select a preset, or make adjustments to the controls manually.
  3. Click Render.

Loudness Standards

Loudness Standard Integrated Integrated Tolerance (+/-) Short-term Momentary True Peak Gating Notes
AES AGOTTVS TD1006.1.17-10 -16 2.0 Off Off -1 On
AGCOM 219/09/CSP -24 0.5 Off Off -2 On Italy
ARIB TR-B32 A/85 -24 2 Off Off -1 On Japan
ATSC A/85 -24 2 Off Off -2 On USA, Canada, Puerto Rico
BS.1770-1 -24 2 Off Off -2 Off International
BS.1770-2/3/4 -24 2 Off Off -2 On International
EBU R128 -23 0.5 Off Off -1 On Europe
EBU R128 DPP -23 0.5 Off Off -3 On Europe
EBU R128 (South Africa) -23 1 Off Off -2 On South Africa
OP-59 -24 1 Off Off -2 On Australia/New Zealand
Portaria 354 -23 0.5 Off Off -2 On Brazil

RX 9.3.0