Pyramix Mixer
12 - 117
Ramses MSC reference guide
Pyramix Mixer : Creating and Configuring Mixers
M&S Stereo Strips
What is M&S?
M&S stands for
Middle
and
Side
.
M&S
is a microphone technique which outputs
Sum
and
Difference
signals instead of
Left
and
Right
(also known as
LR
,
AB
or
XY
). These
Sum and Difference signals are often known as
M&S
although this nomenclature is often
a source of confusion...
Sum
and Difference
signals can be created from a conventional Left, Right source. For
example, by using the Pyramix
MS Encoder
plug-in.
Decoding M&S
A
Sum and Difference
or
M&S
decoder reconstitutes Left and Right by adding the
Differ-
ence (S)
signal to the
Sum (M)
signal to produce Left and adding the
phase-reversed
Difference (S)
signal to the
Sum (M)
signal to produce Right. This is often represented
as:
L = M + S
and
R = M - S
Benefit of M&S
In mixing as opposed to recording, the main practical benefit of manipulating a signal in
the Sum and Difference domain is true control over the
width
of the image. Pyramix can
handle these signals directly thanks to the provision of
M&S Stereo
strips.
M&S Strip controls
An
M&S
strip stereo bus send has three controls. The center knob determines the
Sum
(M)
contribution to the Left and Right outputs. The
L
knob determines the in-phase
Differ-
ence (S)
contribution to the Left output and the
R
knob determines the out-of-phase
Dif-
ference (S)
contribution to the Right output. The
L
&
R
knobs are ganged by default. To
move them independently click and drag with the
Ctrl
key held down.
The
Phase
of both the Sum and Difference channels can be reversed. The single
Ø
button has four possi-
ble states:
Black:
No phase inversion
White:
Sum (M)
channel inverted
Red:
Difference (S)
channel
inverted
Blue:
Both channels
inverted
Inverting either Sum or Difference results in the image being reversed left to right.
Note:
If the
Input meters
consistently show
S
higher than
M
then either the image is very
wide and unlikely to be compatible for a mono listener or the
M
and
S
inputs have become
reversed at some point. Regrettably, this is extremely common when dealing with location
recordings in film and TV.
Creating and Configuring Mixers
If one of the numerous mixer presets does not quite suit your application it is simple to modify an existing
mixer, create one using the Mixer Wizard or design one from scratch. The Wizard can be started from an
existing mixer by right-clicking anywhere on the mixer surface and selecting
Settings > Wizard...
