Volume lowers when converting a mono track

Using Windows XP and Audacity 2.0.5.

I have a wav stereo file in which one of the channels is barely audible. I used the split option to create the left and right tracks, but the volume was still too low, just until I changed into a mono track it became audible. The other track doesn’t have any problem. Each and every time I convert the mono track into a channel track, the volume becomes inaudible. I exported both tracks into separate wav files, closed and open Audacity and imported the files, with the same results. I also tried using wavegain on the problematic track before importing it back, without any success. I cannot use normalize nor amplify because the track is at its peak.

Any suggestions? Thanks in advance.

Please post a screenshot of that stereo track.

Which exact “split option” did you use?

Does the track look like it is at its peak?

I have a wav stereo file in which one of the channels is barely audible.

Do you know how the file was created? What microphone? Was it made with a video camera? Separate sound?

Was this show associated with a newspaper or other production company?


I’m not sure I understand what you’re saying but there is a fairly-common situation where converting a track to mono makes a silent file…

If the left & right channels are identical but out-of-phase (one channel inverted) they will cancel when combined… Of course, they won’t cancel completely if one channel is weaker than the other.*

The easiest way to fix that is to Split Stereo To Mono and then click the little “X” to kill one of the channels. Now you have a mono file that you can export. You aren’t really loosing anything since it was the same audio, just inverted.

Alternatively you can use Effect → Invert on one of the channels after splitting to mono.


  • There is one more thing happening - When the left & right channels are combined to mono they are literally summed. If both channels were at 0dB (100%) they would go over 0dB when summed and you could get clipping (distortion). So, Audacity cuts them in half before mixing (mathematically averaging). So… If one channel is weaker the resulting mono will be weaker than the original loud channel.

Hi everyone,

Thanks for your answers. Here is the info requested.

  1. @steve. Image: Stereo Track Screenshot
  2. I first used “Split Stereo Track”, and just after confirming that the right channel really sounded almost silent, I converted it to mono, moment at which it sounded perfectly well.
  3. Yes. I enabled the “Show clipping” option, so those few parts are visible.
  4. @kozikowski. No, it is just a video music file I download. I noticed that it sounded a little strange, something was missing. After I increased the volume a bit, the issue became clear: one of the channels was barely audible. The original file was downloaded as an “.mp4” file, and then converted to wave format.
  5. @DVDdoug. Yes, that would make sense, one channel being the complement of the other, thus making the file silent. In this case the left channel sounds Okay, but the other doesn’t.

After playing a bit with the file, I just discovered something interesting. The issue actually seems to do with some sort of setting in the file telling it to lower the sound of the right channel.

  1. Opened the file.
  2. Select “Split Stereo Track”.
  3. Convert the original right channel (the problematic one) to “Left channel”. Now it sounds perfectly fine.
  4. Convert the original left channel to “Right channel”. Now it is barely audible.
  5. Return the original right channel to “Right channel”. Now the whole audio is almost silent.

Latest discovery. I downloaded a couple of other files, and although the problem is not noticeable because both channels are similar, the issue is actually present in them, too: the sound of the right channel is basically non-existent. Quite surprising, I think!

Do wave files have some kind of internal setting that controls the overall sound level of each channel? Would there be some way to access and set it to a higher value?

Thanks in advance.

Some Windows audio playback-enhancements mix the left & right channels, (whether you like it or not).
That could enable cancellation, & consequent volume reduction, to occur.
Other enhancement’s like “Loudness equalization” can attenuate volume.
Here’s how to switch playback-enhancements off in Windows 10 … https://youtu.be/sxnUjiGgBaI

Do wave files have some kind of internal setting that controls the overall sound level of each channel? Would there be some way to access and set it to a higher value?

No. WAV files are pretty simple… Just a header followed by a series of samples and the left & right channel-date alternates. Some other formats have embedded metadata that can be used to set the volume but as far as I know it’s usually a global value that would affect both channels.

I don’t know what’s going on… But if you can get complete cancelation (or nearly complete cancelation) you don’t have a “true stereo” file because the left & right channels should be different.

For example, a classic vocal remover effect works be subtracting left from right. Everything that’s identical and in-phase in both channels gets canceled and since the vocals are usually “centered” they are canceled along with the bass (which is almost always centered) and anything else that’s in the center. Anything that’s left-only or right-only remains. Partly off-center sounds will be partly reduced in volume. If you have a “stereo” file with both sides identical the vocal removal will give you total silence.

Hi DVDdoug,

I kind of had that idea, regarding wave files, but well, it is better to always ask.

I finally solved this, the problem is actually on my sound card, which must be a very recent situation, something that started maybe like a couple of days ago, because I’ve been checking tracks that I know very well, and now they sound weird, so well, there it is.

Once again, thanks very much for everyone’s help!

Glad to hear you got it sorted.

You can do some investigations with the Audacity tools.

The bouncing sound meters will tell you the condition of the sound entering or exiting Audacity. If you have good sound meters but no audible sound, look for problems in the middle—between Audacity and your ears.

Audacity can have magic problems as well. Say you accidentally bumped the L/R panning control to the left of the stereo track.

Screen Shot 2021-07-09 at 7.48.17 PM.png
The blue waves would have you believe the stereo track is still in terrific shape, but the bouncing sound meters will be missing the right channel (in this case) and you will hear no right sound.

It gets much better. If you have a mono show (one blue wave) and bump the L/R slider, Audacity will create a stereo show in the background. You will still have one blue wave and the info panel will still say mono, but he sound meters will tell you you have an unbalanced stereo show and if you export it, it will be an unbalanced stereo sound file.

Amaze your friends.


Someone will correct me, but you can cause Windows Sound Control Panels to change stereo sound balance. Audacity doesn’t work with devices and channels directly. It goes through Windows.

I once got a computer from the Systems People and I couldn’t get it to pass basic sound tests. Turns out Systems left one of the Windows Sound Enhancements running by accident when they gave me the computer.