Printable Version of Topic

Click here to view this topic in its original format

GMC Forum _ GEAR & PRODUCTION _ Audacity Question

Posted by: Old School Rocker May 23 2008, 04:20 PM

Ok forgive my beginner-ness (I cant figure out a better word right now but anyway ) I was using Audacity and I was wondering, I've heard when using Audacity you can remove vocals and other parts of a song.

So right now im just playing the 2nd Solo for the song "Angel" By Aerosmith over and over and over and over again and now I would like to remove vocals (if you can even do that ) So if anyone has any knowledge of this I would appreciate it if you could help me out.

Posted by: tonymiro May 23 2008, 05:11 PM

There are quite a few bits of hardware (ie Karaoke) and software that claim they can remove vocals from a stereo mix - including Audacity. From what I've seen none of them are 100%.

Vocals tend to be mixed centre and usually with a bit more gain then the instruments, guitar is usually panned off centre. What you are effectively doing in vocal cancelling is wiping out the centre channel - and that means anything that is there: vocals, drums, anything, and rendering back to a much attenuated mono signal. To recover the other 'lost' information means you have to make another pass through and apply suitable low band pass filtering to bring those particular frequency ranges back into the mix. (It's usually low as it tends to be kick drums and bass frequencies that are most evident in the centre channel.)

Centre channel sort of works then because the left and right channels are pretty much identical. (Rarely totally identical though as usually reverb, or some other buss type effect is added in different amounts to left and right channel.) Inverting one will cancel (most of) the other. Instruments off centre though don't give identical left and right channel waveform images. Inversion here won't result in full cut and may end up as a messy compromise.

Anyway if you don't want to try phase inversion using Audacity othen you probably need to use the Invert Effect. I've never tried to do this with Audacity so I can't give you the specifics and don't know how effective it will be play with it - you never know.

Cheers,
Tony

Posted by: Old School Rocker May 23 2008, 05:19 PM

Thank for the help Tony but all that you wrote is like chinese to me but it no big deal anyway il just have to leave it as is and just loop it but thanks for the help anyway.

Posted by: Bogdan Radovic May 23 2008, 06:23 PM

Well in other words don't bother doing it because it can't be done properly