Allen&Heath GL2200 USER GUIDE - Manual (Page 19)

GL2200 U SER G UIDE 19
O
SCILLATOR
/P
INK
N
OISE
& T
ALKBACK
The GL2200 oscillator section provides for two modes of operation:
1kHz Tone Mode
A 1kHz sinewave is provided for setting up input levels on external devices, such as recording
equipment, FX processors and so on.
Pink Noise Mode
A ‘pink noise’ signal, can be used to check the phase and overall frequency response of a
loudspeaker or an array of loudspeakers or for analysing the acoustics of an auditorium. Pink noise
produces equal sound energy per octave over the audio band. It has a “mellow, balanced” sound to
the human ear compared with white noise, which sounds “brilliant and hissy” due to additional energy
at high frequencies.
OSCILLATOR
1kHz/Pink Noise – Selects between the two signal types outlined above.
The level control allows adjustment from –20dBu to +20dBu.
When the TALK switch is pressed, the level of the oscillator/pink noise is reduced by
12dB.
L-R, GRP 1-4, AUX 1-2, AUX 3-4, AUX 5-6 routing switches assign the oscillator/pink
noise and talkback to the required mix busses.
ON – Switches the oscillator/pink noise on and off. LED indicates status. Under-panel
switch prevents accidental triggering of the oscillator during performances.
WARNING! – The oscillator/pink noise facility on the GL2200 is a powerful tool
for audio system checking and setup. However, the operator should ensure that
the ON switch is not selected during performances in order to avoid interruption
of the show and possible speaker damage by accidentally routing the oscillator
to the outputs.
T ALKBACK
The talkback input is connected into the Mic input of the SECOND STEREO INPUT
CHANNEL. By selecting LINE, the signal is fed to the routing switches in the
oscillator/pink noise section and talkback is enabled when the momentary TALK
switch is pressed. Talk to several destinations at the same time by selecting a
combination of routing switches.
Use the MIC GAIN control on the stereo input channel to control talkback level.
+48V is available for microphones which require phantom power.
The ability to talk to auxes (foldback monitors) is important when using the console for
stage monitoring and cueing the performers.
The line jack inputs of the second stereo input channel can still be used when the mic
input is enabled for talkback.
1kHz OSC
PINK NOISE
L-R
GRP
1-4
AUX
1-2
AUX
3-4
AUX
5-6
OSC/NOISE
ON
TALK
2
1
0
4
3
8
10
9
6
5
7
L-R
TALK
AUX5-6
AUX3-4
AUX1-2
GRP1-4
+
PRESS
TO
G
R
P
1
-4
A
U
X
1-
6
R
IG
H
T
P
/A
FL
LE
FT
TALKBACK SIGNAL
FROM STEREO INPUT
DIM
LEVEL
SELECT
PINK
NOISE
GEN
OSCILLATOR
1KHz
/TALKBACK
OSC/PINK NOISE
ON
Oscillator / Pink noise generator and talkback section.