How do I make both channels same volume?

Windows 7, Audacity 2.2.2

I deal with recordings of meetings which are voice only. The voices recorded by the right channel mic are often louder than those on the left. Is there a way of automatically making the two channels the same volume? Normalisation doesn’t seem to work and it’s hit and miss to split the channels and do it by hand. Thank you.

Audacity doesn’t do anything in real time—during the recording.

I can think of a couple of ways of automating the balance. Install Chris’s Compressor…

…and run it on each side after you split them. If you change the first value, Compress Ratio from 0.5 to 0.77, Chris will simulate broadcast compression including auto volume.

It’s a little more work, but you can apply the AudioBook Mastering tools to each side. Their job is to force whatever you have into the restricted AudioBook Format including loudness.

It’s only three tools, but one of them is custom.


Steve’s RMS-normalize plugin has the option of (RMS) normalizing stereo-channels independently …

RMS Normalize independent-option.gif
In that case no need to split the stereo-pair and apply the tool twice.

And if you do it that way, make sure you have View > Show Clipping turned on. That will produce red bands in the blue waves that have gotten too high.

That may sound OK in Audacity, but it may click, tick and crack when you get the sound files out of Audacity into the real world.

You can fix that by normalizing to a lower number which will change the volume slightly, or you can Effect > Limiter: Soft Limit, 0, 0, -1dB, No > OK. That will correct the overload without changing the volume. Limiter values stick so you only have to put them in once.


Also note that Steve’s RMS Normalize and the Audacity Effect > Normalize are very different. Steve’s works directly on loudness. That’s the “RMS” part of the name.