Okay, so what I understand about MS is, the mid mic is a card and the sides are fig 8s. Since the lobes of the 8s are out of phase you can get a stereo image by using the two lobes. So would it work to record with one channel as the card, the other as the figure eight, dumping them into cep, making a copy of the figure 8 and reversing the phase on it. or do you have to have a special pre or decoder or somthing? THANKS!
Ideal world using matched (level) mics:
The M picks up left and right side equally: M= S_left + S_right.
The 8 picks up S_left but S_right is inverted: 8 = S_left - S_right
Adding the two (M+8) yields 2 x S_left.
(M-8) yields 2 x S_right.
Real world using unmatched mics:
The output from the M is A x (S_left + S_right)
Output from 8 is B x (S_left - S_right)
Levels on 8 must be amplified by factor (A/B) before you form sum and difference.
M/S processing is not more involved than this.
Edited for readability.
Jon