From: Gerry Schneider
X-Mailer: Mozilla 4.73 [en]C-SYMPA (Win98; U)
Subject: Re: Is it Possible?
Date: Sun, 12 Jan 2003 22:18:08 -0800
NNTP-Posting-Date: Sun, 12 Jan 2003 22:18:06 EST
Organization: Bell Sympatico
Ken McDonald wrote:
> "Gerry Schneider" wrote in message
> > Ken McDonald wrote:
> > > I want to build a circuit to eliminate the center channel from a stereo
> > > input. I think I can do it by inverting one channel and sum it with the
> > > other channel. Or feed both inputs into a differential amplifier. The
> > > problem is I end up with a mono output.
> > >
> > > What I really want is to eliminate the center channel and still have a
> > > separate left and right channel. Is it possible?
> > >
> > > Regards,
> > >
> > > Ken
> > That's the basis for quasi-Karaoke decoders, AFAIK. Do a search on
> > Vocal Eliminator" or some such name, they're an American outfit that
> > in popular magazines.
> > Gerry
> What does "AFAIK" stand for?
> I realize I can make a Karaoke machine but, that's not my intention.
> Although, I do want to eliminate vocal tracks for particular music by
> removing the common signal. This circuit is going to be connected to my
> computer sound card and I will be using headphones to listen.
"As Far As I Know"
The voice usually occupies mainly the center channel, as you of course know, so
differentiating the L and R will do a decent job of removing it. I did this
crudely some years ago with a simple audio transformer connected between
attenuated L and R outputs (no ground), then re-amplifying the audio. Thompson
adds a few more tricks like bass boost to re-establish decent audio quality,