Instrument removal on a stereo track

Effects, Recipes, Interfacing with other software, etc.
Forum rules
If you require help using Audacity, please post on the forum board relevant to your operating system:
Windows
Mac OS X
GNU/Linux and Unix-like
Post Reply
panicmechanic
Posts: 2
Joined: Thu Jul 12, 2018 9:47 am
Operating System: OS X 10.11 El Capitan or later (macOS)

Instrument removal on a stereo track

Post by panicmechanic » Thu Jul 12, 2018 9:55 am

Hey all,

I have a stereo track that has two instruments on it; guitar and harmonica. I'd like to remove the harmonica part. They are nearly completely seperate, however there is a quieter version of the alternate instrument on each track (i.e. when playing the harmonica track on left channel you can still hear a low amplitude version of the guitar track).

I was wondering, seeing as the tracks are nearly isolated, is there a way to tell audacity to take the harmonica track and look for the same signal in the guitar track to remove or reduce it further?

I don't even know if this is possible, I could be greatly oversimplifying the process. If that's not possible, is there an tool I could use to further reduce the amplitude of the harmonica's signal in the guitar track?

Many thanks.

kozikowski
Forum Staff
Posts: 41149
Joined: Thu Aug 02, 2007 5:57 pm
Operating System: OS X 10.9 Mavericks

Re: Instrument removal on a stereo track

Post by kozikowski » Thu Jul 12, 2018 1:19 pm

is there a way to tell audacity to take the harmonica track
Sure, but you don't have a harmonica track. You have harmonica plus a little guitar.

While it seems you should be able to do that, in practice, no combination of math and phase flipping is going to get you there. Plus, the "ghost" guitar in the harmonica track is not just a quiet version. If it's a live performance, the environment is going to be different, front and back sides of microphones are different, and if it was done in post production (unlikely), many mixers will add effects to make the combination sound natural.

The default Audacity position is we can't split a mixed performance into individual instruments, voices or sounds. Even if you had two MP3 versions of the performance, one "clean" and one not, MP3 distortion makes the two versions different enough to prevent cancellation.

It's a popular request.

Koz

panicmechanic
Posts: 2
Joined: Thu Jul 12, 2018 9:47 am
Operating System: OS X 10.11 El Capitan or later (macOS)

Re: Instrument removal on a stereo track

Post by panicmechanic » Fri Jul 13, 2018 9:29 am

Ah fair enough. Thank you for the explanation, very helpful.

Post Reply