Topic: Mid side question?

[Swampy]

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!

[todd e]

you got it right, most folks use a waves pluggin for the post matrixing of the m/s channels.  some pre's allow for a mix on the fly, but that is somewhat limiting.  if you use wavelab, the pluggin is a snap, but i didn't recognize that other program name.

good luck!

[jk labs]

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

[hexyjones]

Interesting...so does this mean that MS is more of a "stereo effect" than a true stereo image...?