saturated recordings

Special Interest Groups Audio Processing
1

Hello
I searched several topics before asking this question but found no answers.
I have quite a lot of saturated (choir) recordings I’d like to “clean up”.
Is there some way to do this with Audacity or a plug in? Just limiting the volume helps a bit but the distortion from the original saturation is still there
Maybe I’ll have to redo the recordings…
Any help gratefully accepted
Keith

2

There’s not a great deal you can do as the “source material” is badly damaged.
You may be able to achieve minor improvements with Eq, but you’re unlikely to gain significant improvement.

For occasional digital clipping, there is a feature in Adobe Audition, but I’ve never seen anything similar in free software (or any software costing less than a few $100’s)

If your original recording is in stereo, it’s possible that one track may be better than the other, so you may be able to salvage something. Other than that I think that you will need to re-record.

3

9 times out of 10, asking to fix a clipped track is like asking to fix a batch of cookies that was burned.

Remember the rule measure twice, cut once? It applies to audio as well. Make sure your recording levels are set correctly before recording. Ask the choir to sing as loud as they can for a few seconds to find out what the peak is going to be, and then adjust the input on your equipment so that this peaks about -6dB (this is equal to .5 on the linear scale).

4

I’ve had some success using the waveshaper, click remover and compressor in audacity, but it really depends how bad the problem is.

5

Going back to alatham’s analogy of burnt cakes, it’s a bit like scraping off the black bits and sticking on some fresh crumbs to take their place. :slight_smile:

A similar technique (v.1.3.4) if there’s only occasional momentary clipping is to zoom in tight on the clipped signal, reduce the volume a little, then apply some severe low pass filtering to remove the square corners of the clipping, amplify it back up to 0 dB, then use the “Repair” effect to remove the glitches at the beginning and end of the processed section.