Audacity Forum

Is possible to subtract one track from another to extract a single track that's been mixed in & so is not currently available on it's own.
For example I recorded a track then did an over dub, but didn't have audacity set up correctly. That mean't only the overdub is still independently available on it's own track.
The 1st track is now only available mixed with the over dub. If I could subtract the overdub from the mix then I'd have the 1st track on it's own.
I'm sure I read somewhere this is possible but can't find that post.

I can't think how you managed to do that (I'd be interested to know)

Are the tracks mono or stereo?
If they are mono, you can "subtract" one from the other by using the "Invert" effect, then mixing the inverted track with the other track.

A couple of things to note:

1) When you mix the tracks, the "Quick Mix" process will remove the tracks that are being mixed, so you will need to export a copy of the overdub track before you do the mix. Select the overdub track then use "Export Selection as WAV" so that you retain a backup copy of the overdub track.

2) For the "subtraction" to work, the overdub waveform on the mixed track must be totally identical to the independent overdub track. If the volume levels are not the same then the subtraction will not equal zero. Depending on how the mistake occured, it may be necessary to adjust the volume levels of the tracks (use the track volume slider) to make the overdub as close to equal as possible on both tracks before you mix them.

Was the overdub you singing live in front of a microphone and the guitar (for example) was the original track? Describe the show.

I suspect the first thing I'd do is Save the Project so if you do something really silly, you can get back to where you are right now. Don't save anything else with that same project name.

As stated, it's really difficult to get Audacity to do what you did. So either it didn't really do that and the original track is hiding, or you discovered a really messy combination of keys that nobody's ever hit before. If the latter, expect to become a celebrity as the developers try to get you to do it again.

--- Now that it's too late, always save WAV versions of all your work before you mess with them. This is the safety backup. People consider it really bad form if you destroy some of their original sound recordings.

If you do straighten this out, immediately install Audacity 1.3.12 and start using that. Audacity 1.2 is really, really old and isn't the most stable on modern computers.

http://audacityteam.org/download/

Koz

of course you can always subtract one track from another one
what you get is the question [that kane would ask of grasshopper ]