Allen&Heath GL4800 USER GUIDE - Manual (Page 28)

28 GL4800 User Guide
THE MONO MIX - The GL4800 includes an independent mix buss
for the M (mono) output. Each channel and group can be routed
direct to this buss by pressing the related M routing switch. The
signal is sourced pre PAN control so that the mono mix is not affected
when the stereo mix image is adjusted. The M output can be a
different mix to LR. If you want the mono output to be the sum of the L
and R mix then use the L(R) TO MONO controls to mix L and R to M.
Some typical applications of the Mono output:
Centre speaker feed - To fill out the sound between the left and right
speakers. This is usually positioned to benefit the audience nearest
the stage.
Mono PA system - Here, the L and R mix can be used as additional
subgroups or for a separate stereo recording.
Sub bass feed - To drive a speaker designed to reproduce the very
low frequency sounds in multi speaker systems.
MATRIX SENDS FROM MONO - The mono buss signal may be
mixed into matrix 1 to 4 by adjusting the matrix send controls. The
signal is sourced pre or post the M fader by selecting the POST/PRE
switch.
MONO MASTER - The M mix is controlled using a 100mm fader. As
with the groups and LR: automated MUTE, a pre fade mix meter,
matrix sends, insert and AFL are available.
STAGE MONITOR MODE - Unique to Allen & Heath consoles, an
underpanel mode switch determines how the Mono section operates.
In the normal up position it provides a conventional mono buss output
for front-of-house applications as described above.
When pressed, the Mono section is reconfigured as the stage monitor
engineers listen wedge control. The Mono output becomes silent until
an AFL or PFL is selected. Pressing PFL automatically overrides any
selected AFL. The Mono section AFL switch is disabled in monitor
mode. Pressing AFL monitors the output post insert and post fader.
You can hear the effect of any EQ or signal processing inserted into
the outputs. The listen monitor is controlled using the 100mm MONO
fader with MUTE switch.
Connect the Mono output to an amplifier driving the engineers monitor
speaker. It is best to use a speaker identical to those used for the
stage monitors, usually wedge shaped (hence the term listen 'wedge').
You would not normally plug an EQ into the listen monitor as it is best
to hear the selected listen source exactly as the performer hears it on
stage.
Pressing TALK dims the listen output by 20dB to prevent possible
acoustic feedback between the local speaker and talkback mic.
M
MTX
+6
0dB
+6
MTX
0dB
+6
MTX
0dB
+6
MTX
0dB
M MIX
AFL/PFL
PRE
POST
WEDGE MODE
1
2
3
4