How to balance channel volume in Adobe Audition?

Question

I've recorded audio with a Zoom h4n and the right channel is louder than the left one.

How do I balance them to make them even in Adobe Audition?

People in threads over the internet just say it is possible to do but they don't say how. Is that even possible in Adobe Audition? It seems such a trivial task. Maybe I'm using the wrong terms to search.

For now I just want to do that in post-production. It would be nice though to know why does the Zoom h4n captures sound this way. It's been always like that (the right channel louder).

Answer 1

There are several ways to do this. Simple answer: You can edit each channel separately. When the wave-form is selected, you can hit the up arrow key or down arrow key to change the selection to left only or right only. You can choose to Normalize each channel to 100% or adjust them by ear. Or you can play it totally safe and mix either channel separately into a mono track. Even simpler answer. Open up the stereo expander effect. There should be a window on top that allows you to adjust the center pan.

Answer 2

Subtract the RMS values from each channel to get a numeric difference, which then can be applied to one channel. Here is how to do that:

1. In the Waveform Editor, choose Window > Amplitude Statistics.
2. Notice the average RMS values for both channels on the General tab (it is probably somewhere around -20..-30 dB). If you see e.g. -30 dB for left and -20 dB for right, it means that the left channel in RMS average is 10 dB lower.
3. Open the Amplify effect (Amplitude And Compression > Amplify). Now turn down the right channel 10 dB (you may need to uncheck link sliders). The reason why you want to turn down right channel instead of turning up left is that it may produce clipped peaks above 0 dB in the left channel. You may use a limiter to raise the overall volume.