From: John Woodgate
Subject: Re: Is it Possible?
Date: Mon, 13 Jan 2003 19:30:39 +0000
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Mon, 13 Jan 2003 21:25:26 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Ken McDonald
wrote (in ) about 'Is it Possible?', on Mon, 13 Jan 2003:
>I was hoping there was
>a fairly simple way to extract the center channel, invert it and sum it with
>the left and right signals.
The 2-channel stereo signal is precisely that; 2 channel. However you
matrix (do algebra with) the 2 channels, linearly, you still get just 2
discrete (orthogonal) channels. You can get any number of pseudo-
channels if you allow crosstalk (correlation or 'limited separation')
In a previous post today, I showed how to get two *outputs*, but they
are not independent, they are 100% anti-correlated. Even so, they may
well do what you want.
>If I could do that, I would have the left and
>right channels separate ( I think).
No, you would not.
> Unfortunately, I don't know how to
>extract the center channel. Removing it is fairly simple and can done in a
>variety of ways ( hardware and software) but, you end up with the left and
>right signals mixed together (mono).
No, you end up with L - R, the 'S' ('surround' or 'difference') channel.
The 'centre channel' or M signal is L + R. The best you can do if you
want two channels out, without the M channel, is to get S and -S.
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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