[PD] Phase Cancellation

[Chuckk Hubbard]

On 8/5/06, Mathieu Bouchard <matju at artengine.ca> wrote:
> On Fri, 4 Aug 2006, beau c wrote:
>
> >  I am trying to extract a drum loop from a soundfile, which has a violin
> > loop mixed in. Earlier in the song I got a clean pass of the violin with
> > by itself. I was wondering how I could change the phase of the violin
> > loop by 180 degrees so that when I mixed it in [+~] with the other
> > sample the violin loops would cancel eachother out. Leaving only the
> > drum loop. Does anyone know how to do this with pd? Or any other
> > programs/plug-ins?
>
> Chances are that it won't work because the violin isn't played in exactly
> the same way. If the violin wasn't sampled and replayed exactly the same,
> it won't work. Each manually replayed violin note will have different
> timing and thus a rather random phase difference from the original one.

If it's a loop, though, and *if* the loop is exactly the same by
itself as it is mixed, wouldn't the only differences be from
resampling and maybe interpolation?  If so, that's probably
imperceptible.

-Chuckk