Multichannel Loudness Normalisation on greater than 4 channel sequences ignores process checkbox

[trevora3]

1. Version of the app
   v24.x v25.5.0
   
   
2. Platform and OS version
   MacOS 15.4, also Win10 I think
   
   
3. Basic steps to reproduce the problem
   When doing multichannel exports it is often useful to have Loudness normalisation on the full mix of the export. 
   The 'process' checkbox, if unchecked, should bypass loudness normalisation for that stream. 
   
   Setup multichannel sequence with 8 outputs. 
   Export 8ch (e.g. WAV) with LU set to normalize on Stereo stream 1 only (i.e. channels 1&2)
   
   
4. Expected result and actual result

Expected -
A1&2 normalized to LU setting (and loudness report xml to indicate that the other streams are not processed).

Actual -
ALL streams are normalized to LU setting (and loudness report indicates they are processed). 

It does work as expected for 4 channel sequences.

XML for 8ch:

<Stream ChannelCount="2" Index="0" Processed="true">

<Stream ChannelCount="2" Index="1" Processed="true">

<Stream ChannelCount="2" Index="2" Processed="true">

<Stream ChannelCount="2" Index="3" Processed="true">

XML for 4ch:

<Stream ChannelCount="2" Index="0" Processed="true">

<Stream ChannelCount="2" Index="1" Processed="false">

[jamieclarke]

Hi @trevora3 -  Thanks for submitting your bug report. We need a few more details to try to help with the issue.
Please see, How to Report a Problem.

Can you post a screenshot of your audio track mixer and all of your export settings?

Is it just the report that is not correct?

Sorry for the frustration.

[trevora3]

Thanks for the response Jamie

No the exports are incorrect, matching the XML. Not at computer ATM but sequence is simple 8 channel multichannel with tracks routed correctly (e.g. DX submix to 5&6, FX submix to 3&4, MX submix to 7&8, Master mix to 1&2)

Export presets (OP1a or Wav or mov, doesn't make a difference) are set to 8 channel 24 bit, with Loudness normalisation set to 4 stereo streams, 1-2 with process checked, other 3 with process unchecked.

Will try and supply a media managed project and presets if you can't replicate.

[jamieclarke]

Hi @trevora3 - Have you tried adding the Loudness Meter effect in the Audio Track Mixer? It may give you more precise control, especially since your sequence includes submixes and has a more complex setup than usual.

[trevora3]

Hi @jamieclarke - yes we use that to get us in the landing zone but it's very hard to be absolutely precise across long programmes in quick turnaround.

So we have to ensure the spec is met (or AQC will fail).

So the Loudness Normalisation on export is an *excellent* feature.

It's just not consistent with 8ch exports. (I presume it's > 4 channel exports that are the issue).

[trevora3]

@jamieclarke 
https://drive.google.com/file/d/1sqDskPYGIm8Ff7LIwJ2MyybQBFfVq3Zq/view?usp=sharing

There's a project, media, export presets, screen grabs of track mixer and LU settings.

Also a screen rec that kind of explains how the sequence is setup and where the exports have gone wrong. 

The 4ch export does not null on channels 1-2 (because it has been correctly normalized) but DOES null on channels 3-4 (because it has, correctly, not been affected on export).

The 8ch export does not null on anything (because each stereo pair have been normalized - which is incorrect in the case of stems and can result in very undesirable results). 

[jamieclarke]

Hi @trevora3 - Thank you for the files. We’ve logged this as a bug and will update this post once we have more information to share.