Allen&Heath GL4000 USER GUIDE - Manual (Page 20)

19
S
TEREO
M
ICROHONES
This example shows two
cardiod microphones arranged
as an X-Y coincident pair. This
minimises the phase
differences which can cause
problems when the mics are
arranged as a spaced pair.
The mic input stages are
patched into a stereo line input
for single fader control. The
second stereo channel may be
used for an independent line
input.
A
BOVE AND
B
ELOW
M
ICROPHONES
Here, two microphones are
used on the snare drum to get
the best balance between stick
sound and skin resonance on
top, and snare sound below.
Reversing the phase of the
lower mic can compensate for
the opposite skin resonance
between the mics. Signal
processing such as noise
gates can be patched in as
shown.
The M-S stereo configuration is often
preferred when simultaneous mono feeds
are derived from the stereo signal. Here,
a cardiod and a figure-of-8 mic are
positioned on the same stand. The
cardiod picks up the "middle" (mono)
signal, and the figure-of-8 the "side"
(stereo content). Stereo is extracted
from the mic signals by producing sum
and difference channels. When
combined the stereo content is cancelled
out leaving true mono. Balance the two
faders to achieve the desired image.
M-S S
TEREO
M
ICROPHONES