Function, controls and their eect
M/S technology - The term M/S technology means that a stereo signal is divided into its mid and side
signal components. The mid signal (M) contains all signals that are identical on the left and right side.
The side signal (S) contains the non-identical signal components. After the mid (M) and side (S) signals
have been processed separately (usually with equalizer, compressor, limiter, reverb, delay or lter), the
signals are then precisely merged again to form a stereo signal.
Function - The W2389j module in the api®500 format represents a compact and precise M/S encoder
and M/S decoder in an api®500 double cassette format.
Stereo in-and outputs are provided on the backside of the connected lunchbox.
The in-and outputs on the frontside of the W2389j are used to connect the M and S signals with any
external processing device.
Controls
mode The illuminated M/S push button enables a quick and visible change between the M/S and
the stereo signal processing. This allows a quick and reliable eect assessment of the inserted signal
processors.
bypass L/M This illuminated push button is used to check the mid signals (in M/S mode) or the
components of the left channel (in stereo mode).
bypass R/S This illuminated push button is used to check the side signals (in M/S mode) or the
components of the right channel (in stereo mode).
W2389j (f) M/S-Master junior application examples
• Microphone recording using M/S microphone setup
(in this application the two microphones are connected to the lower XLR sockets on the front panel)
• Conversion of stereo signals into mid and side signals
• Conversion of the mid and side signals back into a stereo signal
• Converting into M/S signals, to modify the stereo base width by changing the side component level.
It is sucient to plug to the XLR in- and outputs of the side signal (R/S) and then press the bypass L/M
switch (e.g. with a symmetrical voltage divider or a symmetrical potentiometer)
• Post correction of the stereo width from mono to overbase width (super-wide stereo). To reduce the
stereo base, the side signal components must be reduced and to enlarge the stereo base, they need to
be increased. Suitable accessories can be supplied on request.
• Separate editing of mid and side components for further processing by external signal processors
• Reweighting of reverb and soloist parts in existing stereo recordings
• Insert of vintage and/or mono devices in M or S. Suitable adapters from balanced to unbalanced signal
routing can be delivered on request.
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