From: "Ken McDonald"
Subject: Re: Is it Possible?
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Date: Mon, 13 Jan 2003 22:51:42 GMT
NNTP-Posting-Date: Mon, 13 Jan 2003 17:51:42 EST
"John Woodgate" wrote in message
> I read in sci.electronics.design that Ken McDonald
> wrote (in nilink.net>) 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
> >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')
> between them.
> 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.
I appologize. I don't know what "100% anti-correlated" means.
> >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
> >variety of ways ( hardware and software) but, you end up with the left
> >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.
I saved your other post. Thanks. It looks like I don't know what I'm talking
about. This is the first time I've tried to work with a stereo signal. I am
able to design a circuit to perform as you suggest in your other post but, I
don't understand why it has to be done that way. I would like to learn more
about this subject. Are you aware of any web sites that may have a tutorial
> Regards, John Woodgate, OOO - Own Opinions Only.
> Interested in professional sound reinforcement and distribution? Then go
> PLEASE do NOT copy news posts to me by E-MAIL!