Monoizing a stereo file...the visual

I have limited experience converting .wav stereo files to .wav mono files. So perhaps a solution exists in Wavelab that I’m not finding?

If nothing similar exists I am wondering if the below is something that could be incorporated as a feature in a future Wavelab version?

Conversion is easily done with batch processing. But I am wondering about the visual where you can see the stereo vs. mono parts in a single .wav.

(skip to :45 if in a hurry)

Make a stereo selection then go
Edit > Copy selection to new window > Convert to Mono (Mix)

or use
File / Save as and select one of the mono options in the channel field

See p.147 of user manual.

If you want to see both waveforms simultaneously then just open the files in the audio file workspace using two horizontal tab displays.

Thanks but that isn’t what I’m referring to. In the video you can see the stereo areas vs. mono areas as they are different colors in the same wave.

The purpose of course is when clients send you what the believe are totally mono files, but as the video demonstrates, that is not always the case.

Don’t know how to do what the video does.

If you are looking for a way to provide visual proof that a stereo file contains mono information, simply open the Phase meter. If it is mono then you will have a single straight line and the correlation meter will be pegged at “+1”. Take a snap shot of that meter and send it off.

Unless I’m misunderstanding you, a phase meter will only show the information when you play the .wav file. What I’m asking is something where the user can look at the entire .wav file at once and see the mono vs. stereo parts in the same .wav as demonstrated in this video at :45 seconds

Maybe I should just buy this application, but first thought there could be something similar in Wavelab.

If you divide the stereo file to 2 mono files, you could use this tool:

Or use an MS plugin to convert to M and S, and observe whether the S channel is flat zero.


I must say it could be helpful, seeing mono and stereo in ‘stereo’ files. But the way this StereoMonoizer shows it looks a bit clumsy to me though.

I would propose a new tab in Wavelab, next to the spectrum and loudness tabs, indicating not only stereo or mono but phase coherence. Or, stereo ‘spread’ if you will - very helpful in seeing not only if a file is really stereo, but also showing mono compatibility (how much of Left is anti-Right). Just a thought: Red color is R channel only, Blue is L channel only, Green is L=R and say, Yellow is L=-R. And all shades of inbetween colors…

Thanks guys!

2 ways I never considered plus a good suggestion from Arjan.

Too many times I have received what was believed to be a stereo file only to find out it was mono. That’s opposite of the 2nd video where it shows just a small portion in stereo.

Being able to import a file and visually look at it for stereo or mono verification without relying on playing the file and looking at a phase scope would be nice.

(OT posts and their responses removed…)

Forgive me if I have misunderstood you, but isn’t this there already? Pg 423 of the manual.

And on my second screen, these meters … along with the phase meter … are there as a default.

I always check mono fold down anyway, and the meters always centre when I do so.

Again, apologies if I have misunderstood.

Paul, you are right that with the meters you can see L/R behaviour or mono real-time, but you’d have to play and watch each file. With a new ‘phase coherence’ tab like the loudness tab you’d have an overview of the whole file in one glance, where maybe in the middle of a ‘stereo’ file a part could be mono or anti-phased.

Ahhh … I see the difference now. Thank you.

Thanks Arjan P. I think this is what should be emphasized, and it’s clearly demonstrated in the video.

This can be accomplished with WL right now.

Add all the files you wish to inspect into a batch processor with the “L/R->M/S” plug and save to a seperate folder (which can be discarded later).

The resulting file will show correlated information (sum or “mono”) in the top track and uncorrelated information (difference or “out of phase”) in the bottom. Visual inspection of phase relationship for the entire file is then seen in a glance. See attached pic.

While mildly interesting to test various files for phase relationships, I don’t find this a necessary QC procedure in practical music production. What would really be helpful is a process that can detect any lossy processing in any supposed linear Wav’s coding history and return a printable report of the findings.

Well, different strokes for different folks. Ofcourse there are ways to find out phase coherence without realtime monitoring, but a tab showing it instantly would be helpful to me. OTOH, I never use the loudness tab, and detecting lossy processing is of no use to me either.

Fair enough. Maybe I am missing something, interested in what kind of scenario you have found yourself in where this would be helpful.

We receive mastering sources which have mistakenly been transcoded from mp3/aac lossy processing often enough that we need to be on guard for it. Its a big problem which we typically catch during the mastering session or in proofing. But this is a big time waster. Better to vet these files out upon delivery, before the session starts.

For the record, I don’t want any time wasted on adding mono detection or lossy codec detection integrated into WL. There are more pressing bug fix repairs to address first. Anyway, I would prefer a codec detector to be a stand-alone app.

I’m not giving up on this feature request.

Please watch the video and fully understand what the tool achieves. Is this not something very useful for those with clients that send all kinds of files?

If a work-around exists in Wavelab, such as PG’s suggestion, I don’t think it is very eloquent.


Granted their tool can analyze different rates and stereo files or mono and do the conversions for you from a folder of files, which is really nice.

But for the views, or audition, can’t you already get basically the same informational views in Wavelab 9, by loading all of your files on one track of a montage, right click anywhere under Lf:Rf to the left of the track, and select “split into mid/side mono tracks”? Then you can look at a whole bunch of files at once to see whether they’re mono or stereo, and where the differences are. Or you can solo and audition the difference.