The old Phase Shift trick...

[kravinski]

Hey there. I am hoping some of you audio engineers out there could help me out. I remember learning about shifting one side of a stereo track out of phase to really "hear" (ie. cheat) what is going on in a mix and to isolate instruments. Is there any way to do this to isolate drums (which are usually all over the mix)? For instance, I am trying to isolate the drum kit on a Beck tune for a project I am doing. I am able to isolate the other stuff (sitar, guitars, SFX) but the drums are either totally there or totally not.

I split the stereo into 2 mono tracks panned hard L and R respectively. Then I switch the phase of one track, and I can get some isolation. Does this sound right? any other tricks y'all can pass along??

Thanks.

--Matt

[The Dougfather]

Why don't you use a gate, kick drums are very easy to gate because of they're sharp attack and decay.

Cheers

[Phil Ogden]

AFAIK the procedure you outline is used to remove sounds from the centre of the stereo field (usually the vocal). The theory being that any sounds with equal components in the L and R channels will be cancelled when one channel is phase inverted. In reality, this is not foolproof as FX (e.g stereo delay) are rarely equal in the L and R channels.

It seems highly unlikely that this method would be successful for a stereo kit which, as you say, is likely to be panned unequally.


http://www.myspace.com/philogg

[Len8]

That technique only works to eliminate things that are mono in the mix. By inverting one channel you basically cancel out the waveform. It's done sometimes to remove vocals from mixes. It would depend on the mix whether it would work or not. A lot of times even drums aren't centered, and the stereo room mics would definitely still be in the mix.

Len