Adjusting channel level

Special Interest Groups Audio Processing
1

Hello there,

I’ve been recording my favourite radio program using mplayer (dumps to wav), then encoding to ogg. For some reason, probably related to the web broadcast, the result is far from satisfactory. In the case at hand, the right channel is clearly at a lower level than the left - it sounds quieter, and Audacity shows the same waveform, though with a tenth of the amplitude.

Since this is radio, I’m not overly concerned with quality. I would like to have the same volume on both channels, though. I thought about converting to mono from the higher channel, than to dual-channel mono. Notice, though, that I still have a stereo recording, its simply that the right channel has a really low gain.

What would be you suggestion for equalizing.adjusting the channels?

Renato

2

Try splitting from a stereo to two mono tracks, then you can manipulate the “right” one. When satisfied, you can burn it back into whatever format you want.

3

When you mean manipulate, do you mean use ‘>Effect>Amplify’? That’s indeed a good point - how do I go about raising the level, or gain, of a given track?

Thanks,

Renato

4
  1. Import the stereo track into Audacity.
  2. Click on the track’s name → split stereo track. You will be left with two tracks now.
  3. Highlight both of them ([ctrl]+a), and then effects → normalize.
  4. Now both tracks will peak at the same value. They should be close, but won’t be exactly the same perceived volume. Use the gain sliders or the Amplify effect to tweak the tracks so they sound nice.
  5. File → Export. Don’t overwrite the original file and you’ll be left with a new copy of the show in stereo. Don’t save the Audacity Project, it won’t be worth much and will take up quite a bit of space.