[masteringhouse]

Originally Posted by John Suitcase

I was working on a plug to do this, that would output the center, the side, just the left(minus the center), and just the right(minus the center.) It seems to work ok, but it got me thinking that when I was doing this, my 'side' signal isn't really the sides, because one side in inverted, from the encoding process, correct? So, how would I get the 'side' signal for just the left or right?

I realize that if I decode it in the traditional way (the three-fader, with the side flipped on one fader panned opposite the unflipped 'side' fader), I can get the left and right signals back out again, but is there a way to just get the side from one side? It seems that if you could get the center, you could use that to cancel the side portion of just one side, if that makes any sense...

Or am I nuts?

I think that you're basically following the same law as the M/S process but you still need to encode and decode (see the "math" in my link above). If you have the center (M) it consists of (L+R). If you invert either L or R channel with this you get (L+R) - L = R or (L+R) - R = L.