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Jon, (or anyone infact)

Sorry for this OT question- I've mislaid your email address.

I need to cancel out far left and right signals and leaving the middle 
intact. (sort of oppersite to the karaoke effect hehe). Can I do this with 
phase cancellation?- and how could it be done within a Logic enviroment? 

regards

Tom

Hi Tom,

I'm not Jon, but I'll try...

If you mix two copies of the full stereo signal 180 degrees out of phase
from each other, you'll be left with the stereo difference.

N.B. The 'karaoke' formula is similar except it's frequency limited to
closely (well sort of) match or cancel out the frequencies shared by the
human voice. It also doesn't work well with stereo vocal effects (including
reverb). 

Now mix this 'stereo difference' signal 180 degrees out-of-phase with the
original full stereo signal.

You should be left with only the elements common to both channels.

Sounds great in theory. Let me know how you get on.

N.B. Switching the phase 180 degrees is usually performed with an 'invert
waveform' function. It may be labeled differently by some applications.

Phil

PS. The unauthorised use of copyrighted recordings in prohibited. ;-)

> From: terryfunken@...
> Reply-To: AN1x-list@yahoogroups.com
> Date: Wed, 26 Jun 2002 17:58:22 EDT
> To: AN1x-list@yahoogroups.com
> Subject: [AN1x] Re: [OT] Phase cancellation (in Logic?)
> 
> Jon, (or anyone infact)
> 
> Sorry for this OT question- I've mislaid your email address.
> 
> I need to cancel out far left and right signals and leaving the middle
> intact. (sort of oppersite to the karaoke effect hehe). Can I do this with
> phase cancellation?- and how could it be done within a Logic enviroment?
> 
> regards
> 
> Tom

In a message dated 26/6/02 11:11:05 pm, accession@... writes:

>PS. The unauthorised use of copyrighted recordings in prohibited. ;-)
>
>
Phil, thanks for that, but what's this?- are you gonna stop me??

answers on a postcard please!

Tom