Loudness batch processor

Okay here is an idea for the loudness batch processor that could increase my workflow.

Sometimes when mixing for TV I need to process the MIX files to r128 and want to process all the stems to offset by a value given by the offset of the volume of the source mix file to the r128 processed file.

e.g. the DAW bounce is 2.5dB too hot. I would then want to apply r128 LOUDNESS to the MIX file and subtract the 2.5 dB GAIN from all STEMS instead of processing each of them to 0LU.
I know I can analyze the mix file first and then use the gain plugin rather than the loudness plug, but it would be so cool, if Wavelab could automatically find all the STEMS that belong to a MIX file (via filename) and do this without any manual user interaction.
This would help to match leves with punch ins to the re-imported stems and mix files in later revisions of the project.

Agreed. The Meta Normalizer needs this too so we can determine one version as the “main version” to measure and adjust, and then all additional clips/stems are changed by the same amount rather than to the same loudness value.

Not really sure I understand the idea. Couldn’t this be achieved with either of these batch plugins?

Not alone, but together maybe.

Let’s say we have 7 files:

Main Mix
Drum Stem
Bass Stem
Guitar Stem
Keyboard Stem
Vocal Stem
Backing Vocal Stem

The idea would be to normalize the Main Mix to a certain value, say -18 LUFS Integrated or -18 Max Short-Term Peak and this process turns the file down by -3.645 dB, or up. It doesn’t matter.

Then, we would want an option that changes all the other stems by-3.645 dB too automatically.

This would work well for my library mastering work too since I often have a main mix, and then anywhere from 4 to 10 alternate mix versions.

I don’t want them all to be the same LUFS, I want the main version to be a certain loudness and then the alternate versions to change by the same dB amount as the main. Having the alternate versions be the same LUFS/dB as the main version would not be ideal here.

Just like Justin_P writes, his example is maybe easier to understand.
It is not possible with the batch processor at the moment.

Let me rephrase it using my words:
Normalizing the main file to some whatever target leads to an offset of “delta” LUFS (before vs after normalization).
You then want to apply the same delta to the other files, without normalizing them.

If the normalization setting determine that the main file should change gain by X, the other selected files (or all files if none are selected) should also change by X.

Right now the other files also change to the same normalization setting which isn’t ideal for stems and alternate versions.

This is an interesting idea indeed. I don’t know yet what UI for this task, because a file needs to be declared as “master”, something the batch processor currently does not provide.
But I definitely note the idea…

Yes, for me the feature would be ideal in the Meta Normalizer of the Audio Montage but I know others use the Batch Processor.

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PG1 we don‘t really need a GUI for that.

Wavelab could take MIX as the master files and all other names with the same filename - MIX in the name as slave files. Then all you would need is one single checkbox „process slave files by same delta“

Too a hidden way of doing things IMHO. And this name constraint would not fit all cases.

I could imagine two methods:

  • The Loudness Normalizer dialog has an added option to offset all other audio files opened in the file group, whatever their name.
  • With the audio montage: a master clip and the other clips as target for the offset. This is non destructive then. But is there any interest for clips?

The beauty of the filename dependent method is that it could be configured super hassle free and automatic for power users.
All DAWs that allow multiple rendered stems in a single export differentiate the files via an automatic naming dialog that lets users include certain naming scheme. In audio post for TV/cinema we use group names to differentiate the files.
So if you have a template for your Nuendo or PT sessions all your mixes will have “whatever name_MIX” and all your stems will always be called “whatever name_MUSIC”, “whatever name_DIALOG”, etc.
If WL could find the “MIX” file automatically and apply the delta to the other files it would be a hell of a feature for power users.
Start WL batch preset, import folder, hit render, READY.

I mean…
the request is a bit of a “special use case” request anyway, so maybe it’s not worth the hassle making it more complex via a special GUI

I’m not sure what you mean by “is there any interest for clips?”.

I think defining a master clip and then all other selected clips (or all clips of none are selected) get nondestructively set to the same gain value as the main mix was changed to.

Why not. One method does not exclude another.

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I think sounds like good functionality!

If I understand Justin and others right, this should be possible in both Audio Montage and Batch Processor.

As a simple option the name based option could work in many cases I guess.

But as an alternative, wouldn’t it be possible to use something like the current coloring function in Audio Montage!? I.e. you mark one clip as “master”, other clips as “slaves” and unmarked clips are “not included”.

Then clips are visually marked is some way (“Master” and “Slave” stamped on clip or similar), so it is obvious what clips are to be included and not.

Then an option in Meta Normalizer for “Normalize according to Master clip”, i.e. normalizing and adjusting according to Justin’s example:

  • The “master” is normalized to a certain value, say -18 LUFS Integrated or -18 Max Short-Term Peak and this process turns the file down by -3.645 dB
  • The “slave” clips are then changed according to “master” clip, i.e. down by-3.645 dB automatically.

This in combination with the function for automatically resetting previous clip normalization values to 0 could be an example for Audio Montage.

Then you could have a similar solution for Batch processor, where you mark files and perform normalization in a similar way:

  • You have an option for “Normalize according to Master clip” in the batch normalizer window
  • If you add an Audio Montage from example above to the Batch processor the configuration is already taken care of within the AM
  • If you add separate audio files you have to mark “master” and “slave” for each file in the batch file list in some way; in a new column or similar
  • I guess the batch alternative is more complex and will probably need some more work….

Just as some examples for how it could work…


What is the common case: all files located in the same folder?

Yes. All in the same folder.