ALLEN & HEATH GL4000 User Manual page 47

T
HE
Otherwise known as foldback or cue sends, the monitor mixes are created from the
console aux sends. These feed amplifier/speaker systems positioned on-stage for the
performers, backstage for the stage crew, in the pit for the orchestra, and so on.
E
FFECTS
This example shows auxes 5 to 8 sending console signals to external effects units such
as reverbs and multi-effects processors. The sends are set POST so that signal sent
to the effects unit always follows the fader level. The processed signal is returned to
the mix via an input channel, usually a stereo channel.
I
NSERTED
Apart from EQ, delay and other processing inserted into the main outputs you can
similarly plug external signal processing devices into the input channel and group signal
paths. Noise gates can clean up noisy sources such as keyboards when they are not
played. Spill from drum mics can be reduced by gating them. Compressors can be
useful on vocals to control the dynamic range.
L
OCAL
2 stereo headphone outputs and a separate stereo 'local monitor' output with its own
level control are provided so that the console signals can be checked independent of
the main outputs. It is increasingly common during system rigging and sound checking
to monitor using speakers positioned at the console.
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M
ONITORS
The channel aux sends are usually set PRE (pre-fade) for monitors so that they
are independent of the front-of-house mix levels. However, you may chose to
set certain channels POST such as radio mics to prevent 'dressing room talk' or
background noise getting to the monitors.
The aux outputs are balanced XLR to drive the long cable runs to the amplifiers.
Use the inserts to patch in the graphic EQ or other signal processing devices
required. You should 'ring out' the monitors and set the EQ to minimise the effect
of acoustic feedback. The effect on the signal can be checked using AFL.
If you are using the stereo channels for additional mic inputs you can still route
the return signal to the stereo line input and press DIR to LR.
Use WIDTH to adjust for the required stereo image from reversed stereo,
through mono, to normal stereo, and on to 'wide' for enhanced stereo.
Check the incoming 'wet' signal using STEREO PFL.
If it is more convenient to use jack outputs instead of XLRs for the effects sends
then simply press OUT REV to swap with the related matrix or LR2 output.
For local effects (associated only with one channel) press the channel
OUT switch and use aux 10 level to adjust the amount of effect.
S P
IGNAL ROCESSING
Feed the console signal to the device from the INSERT SEND and return the
processed signal to the INSERT RETURN. Plugging into the return breaks the
signal path within the console.
M
ONITORING
Select L-R MIX to check the stereo LR output. This is interrupted by any pressed
AFL which in turn is interrupted by PFL. This lets you monitor the selected output
using AFL (for example matrix) and check channel signals quickly by pressing
PFL.
Turn off L-R MIX to keep the monitors quiet unless AFL or PFL is selected. This
prevents unnecessary distraction during a live performance.
Check the mono compatability of a stereo signal by pressing MONO. The L, R
and M meters also provide a visual check.
DIR