User Guide

124 Chapter 7 Imaging
Setting the Direction Parameter
When Direction is set to a value of 0, the middle of the stereo recording will be dead
center within the mix. If you use positive values, the midpoint of the stereo recording is
moved towards the left. Negative values move the midpoint to the right. Here’s how
this works:
 At 90˚, the midpoint of the stereo recording is panned hard left.
 At –90˚, the midpoint of the stereo recording is panned hard right.
 Higher values move the midpoint back towards the center of the stereo mix, but this
also has the effect of swapping the stereo sides of the recording. To explain: At
values of 180˚ or –180˚, the midpoint of the recording is dead center in the mix, but
the left and right sides of the recording are swapped.
What Is MS?
Relegated to obscurity for a good long while, MS stereo (middle-side as opposed to
left-right) has recently enjoyed a renaissance of sorts.
Making a Middle Side Recording
Two microphones are positioned as closely together as possible (usually on a stand or
hung from the studio ceiling). One is a cardioid (or omnidirectional) microphone which
directly faces the sound source that you want to record—in a straight alignment. The
other is a bidirectional microphone, with its axes pointing to the left and right (of the
sound source) at 90˚ angles.
 The cardioid microphone records the middle signal to the left side of a stereo track.
 The bidirectional microphone records the side signal to the right side of a stereo track.
MS recordings made in this way can be decoded by the Direction Mixer.
Why Make MS Recordings?
The advantage that MS recordings have over XY recordings (two cardioid microphones
that are directed to a point halfway to the left and right of the sound source) is that the
stereo middle is actually located on the on-axis (main recording direction) of the
cardioid microphone. This means that slight fluctuations in frequency response that
occur off the on-axis—as is the case with every microphone—are less troublesome.
In principle, MS and LR signals are equivalent, and can be converted at any time. When
“–” signifies a phase inversion, then the following applies:
M = L+R
S = L–R
In addition, L can also be derived from the sum of—and R, from the difference
between—M and S.