User Manual
22                GL2400 User Guide 
MONITOR, TALKBACK and SIGNAL GENERATOR 
Console Monitor
 Comprehensive engineer’s headphones and 
local monitoring is provided. Select either LR or 2-track return as the 
default source using the L-R / 2TRK switch. Pressing PFL or AFL 
elsewhere on the console automatically overrides the current monitor 
source with the signal from the channel or master selection. The red 
PFL/AFL active indicator illuminates and the console meters display 
the active signal. 
The console monitor meters provide 12 LED indicators to accurately 
display the signal level of the selected monitor source. Reduce the 
gain or level if the red ‘+16’ peak indicator lights. For optimum 
performance the signals should be adjusted to read an average ‘0’ 
with loudest peaks reaching around ‘+6’. 
Use the MONITOR level control to adjust the level in the headphones 
and local speaker monitor. We recommend you use closed ear 
headphones in the range 30 to 600 ohms designed for live sound 
monitoring. 100 ohm headphones are a popular choice. 
 WARNING: To avoid damage to your hearing do not operate 
any close-to-ear monitoring such as headphones for long periods 
at high volume. Continued exposure to high volume sound can 
cause frequency selective or wide range hearing loss. 
TALKBACK Individually assignable talkback is available to all the 
main outputs. Plug in a suitable cable or gooseneck microphone. A 
good quality dynamic or condenser vocal microphone is 
recommended. Note that +48V phantom power is available at the 
XLR as standard. If you prefer, this can be disabled by repositioning 
an internal jumper link. 
 WARNING: Do not connect unbalanced sources or cables to 
inputs with phantom power selected. To avoid loud clicks do not 
press the TALK switch when plugging or unplugging the talkback 
microphone. 
First select the source you wish to talk to. You can select the auxes in 
pairs, useful for communicating with the performers on stage. The 
four groups are selected simultaneously, ideal for identifying a 
multitrack recording. You can also talk to LR, ideal for announcements 
to the audience. Once selected, press and hold TALK to route the mic 
to the required destination. Adjust the talkback level using the TRIM 
control below the TB mic XLR. Pressing TALK automatically dims the 
level of the signal generator if it is turned on. 
SIGNAL GENERATOR / PINK NOISE Press to select either 
pink noise (up position) or a 1kHz sine wave tone as the test source.  
Start with the trim control turned fully down. The generator ON switch 
is recessed to prevent accidental operation. Press this with a pen or 
pointed object. The green indicator lights to warn that the generator is 
enabled. 
The generator signal is routed to any source selected on the switch 
bank above the TALK switch. Use the signal to test the loudspeaker 
system and line up connected equipment. Pink noise is useful for 
quickly testing the full range frequency operation and phasing/polarity 
of loudspeakers. The 1kHz tone is better suited to lining up 
equipment with its steady reading on the meters. 
 WARNING: We recommend you turn off the signal generator 
once you have finished using it to test and line up your system.  
This will prevent accidental operation during the show. 
+16
MONITOR
PFL
TALK
0
GRP
L-R
10
L-R
2TRK
-6
-9
-20
-30
-16
-12
-3
0
+3
+6
+9
OSC/NOISE
TALKBACK
ON
MIN
L
MAX
OO
MIN MAX
2TRK REPLAY
TO LR
R
2TRK
+10
PHONES
SELECT
1-4
AUX
1-2
AUX
3-4
AUX
5-6
PINK
1kHz
MIC
POWER
AFL










