User's Manual
10
Mid/Side Processing
M/S technology is commonly known as a variant of
stereo miking. This technique uses a microphone with
cardioid pattern for the middle signal (M) and another
one with bi-directional pattern with an oset of 90° for the
side signal (S). The main advantage of this technology is its
mono compatibility. FM radio stations use M/S technology for
transmitting stereo signals exactly for this reason.
To create M/S signals, the left and right channel of the stereo
sum are added to generate the mid (M), whereas the side (S) is
created by subtracting the right from the left channel:
M = L+R S = L-R
To decode an M/S signal back into stereo again, M is added to
S for the left channel and S is subtracted from M for the right
channel:
L = M+S R = M-S
The integration of an M/S encoder and decoder into an audio
processor generates new potentials that classic stereo devices
can hardly oer. One of the main advantages is the possibil-
ity to process the middle and side signals separately. This way
you can make the center sound more solid without corrupting
the original stereo spectrum, for example.
Of course it is also possible to enhance the presence of the
side signals in an already nished mix. The stereo width can
be inuenced fast and eectively, too, and it is also possible to
process specic parts of a mix that could not be selected in a
stereo mix as precisely as it is possible in M/S mode.