M-S or M&S

Mit Seit (or Mid-Side). A miking technique which uses a cardioid microphone facing directly into the sound source and a figure-8 microphone facing sideways. The figure-8 picks up the left half of the source with one phase and the right half with the inverted phase. By changing the matrixing of the combined patterns of the two microphones, the width of the apparent stereo image can be manipulated. In M-S matrixing, the output of the side mic is added to the main mic channel to get the left channel, and subtracted to get the right channel. By adjusting the level of the side mics, you can adjust the width of the stereo image. MS techniques are most effective in larger, live rooms where it is possible to get the mics at least 10-15 feet away from the source and side walls. To decode MS signals to normal left and right, pan the M mic to the center and split the S mics to feed a pair of adjacent channels (or a single stereo channel.) Gang the two S-faders together, panned hard left and right. Switch the phase reverse on the right channel. Listening with the monitoring switched to mono, balance the levels of the two S-channels for minimal output (make sure there is no EQ patched into either channel.) Once the two S-channels have been aligned, revert to stereo monitoring, fade up the M-channel and adjust the balance between the M and S signals for the desired image spread. Putting a phase reverse in the M-channel will swap the stereo image; the image width can be varied from mono to stereo to extra-wide by moving the S-fader.

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