Loudness Compliance Applications

Compliance with program loudness specifications is now a mandated reality in many regions of the world. Although use of hardware processors at the output of a playout centre seems an easy solution, this has been proven time and time again to be only a short term fix, leading to client dissatisfaction with the level of processing that is applied to the audio. The quality of your output will be improved by moving the compliance processing upstream, and with using one of our trusted solutions.

Loudness compliance is available as a module within our automated audio workflow system, Engine, or as our standalone/desktop application, Eff.

Our Loudness compliance software is compatible with a range of Loudness standards.

  • BS1770
  • ATSC A/85 (CALM)
  • EBU R128
  • DPP
  • TR-B32
  • OP59
  • AGCOM 219/09/CSP
  • Leq(A)

Our development team monitor various audio forums and regulatory bodies so that we are aware of proposed changes in standards, and can introduce updates in a timely manner.
Engine measures the loudness in all of the channel groupings that you have defined, and can independently adjust all of these to meet your target. It is possible to correct each group to different specifications or target levels. For example, a file containing 16 tracks of audio may commonly have the following layout – stereo, 5.1, second stereo, second 5.1
channel layout

Engine could measure and correct all four of those groups. Alternatively, if some of the groups are M&E, you can exclude those from the measurement/correction and only correct the others. Engine offers complete flexibility.

Click here to read article published in The Broadcast Bridge – Why We Measure Loudness

Read how a customer uses our Loudness solution in their Production workflow

Loudness and Dolby E

Engine is able to support PCM audio and Dolby E encoded audio. Performing Loudness Compliance on Dolby E audio is seamless – there is nothing special to configure, and your output file will be in the identical format to the input file, but with compliant audio within the Dolby E wrapper, and of course with the Dialnorm metadata correctly adjusted.

The loudness module includes a True Peak processor using our own unique algorithm, which ensures that peaks do not exceed your defined thresholds, thus removing any possibility of clipping.

Measurement/Correction Window

Engine contains a configurable Measurement/Correction window. If you know the timecode where your content starts, you can use this to ensure that your -18/-20 dBFS lineup tone is still at -18/-20 dBFS after loudness compliance.
Correction Window

Automatic Tone Detection

If the content starts after a variable amount of tone, then you can use the auto tone detection to intelligently start measurement and correction in a silent period after the end of tone. The algorithm measures tone separately for every channel grouping in the file, so that should you have a stereo and a 5.1 in the file but with different duration tone, or perhaps with tone only on the stereo and not on the 5.1, then the software takes this in to account and adjusts the measurement window independently for the two channel groupings to guarantee true Loudness Compliance.


Legacy measurements such as PPM and VU are not forgotten. Engine can measure and correct to a range of different PPM measurements, with accurately modelled PPM type I or type II ballistics, and VU.
PPM Measurement


Everyone needs reports, and with Engine, you won’t be disappointed. Detailed Loudness reports are available in XML and PDF format. Graphs of your selected measurements can be included.

Click here to download complete report in PDF format

Loudness in conjunction with other Modules

One of the key advantages of Engine is that it is possible to build workflows from any supported module, with a mix-and-match approach. So for example, you might want to use the upmix module, and follow this by loudness correction, then maybe add a Dolby E encode.
Creating these multi-step workflows are very fast to achieve, and offer enormous efficiency savings within Post Production and Broadcast facilities.



Get the Loudness Factbook here

Emotion Systems Loudness Factbook