Mono Input Channel; 10 40 Gain - ALLEN & HEATH GL4800 User Manual

The MONO Input Channel
+48V
microphones which require phantom power.
+48V
Plug the microphone in before switching +48V on or off. Use +48V only
with balanced microphones and cables. No damage will occur when +48V
POLARITY
is switched to balanced non-phantom powered transformer coupled dynamic
MIC
microphones. However, always switch +48V off when connecting line or
LINE
unbalanced sources.
0dB
PAD
20
30 10
-10 40
GAIN
10
50
LINE
MIC
POLARITY - Reverses XLR input pins 2 and 3 to correct for reverse wired
6
-14 40dB
60
cables or reversed phase signals.
50Hz
HPF
30 100
acoustic feedback between the microphone and loudspeakers in live sound
20 200
mixing.
OFF 400Hz
MIC/LINE (PAD) - Selects line input sensitivity when pressed, microphone
7kHz
when released. Note that with the line jack unplugged the switch acts as a
3k 10k
20dB pad for high output microphones or line input on XLR.
GAIN - Use this control with the MIC/LINE switch to adjust the channel input
2kHz 20kHz
HF
sensitivity to match the connected source (-60 to +14dBu) to the console
operating level (0dBu). The gain should be set so that the channel meter
reads an average '0'.
-15
+15
LO-CUT FILTER
Q
microphone proximity popping, stage noise and transport rumble. Can be
3k
1k
5k
used to clean up sounds that do not have much bass content such as vocals
700 7k
(around 150Hz), separate out the top end of a drum kit (400Hz), reduce the
500Hz 15k
handling noise of acoustic instruments, and so on. Select the required cut off
HM
frequency by sweeping from fully anticlockwise (filter off) to the maximum
400Hz. Setting the cutoff to 50Hz will have little effect on most program
material but will protect the low frequency speaker drivers. The response
-15
+15
drops by 12dB per octave below the cut off frequency.
Q
180Hz
EQUALISER - This provides separate, simultaneous control of 4 frequency
60 300
bands. Each band may be boosted or cut by up to +/- 15dB centred on the
45 450
selected frequency which may be swept across a wide range.
35Hz 1kHz
LM
equaliser to correct for tonal deficiencies in the source such as acoustic
resonances or poor microphone response (corrective EQ), or to change the
tonal balance, for example to brighten up a guitar so it cuts through the mix
(effective EQ). You may need to adjust the input GAIN control when using
-15 +15
100Hz
excessive amounts of EQ to compensate for the change in overall signal
50 150
level.
20Hz 200Hz
HF and LF affect the high (treble) and low (bass) frequencies respectively.
LF
These have a shelving response which means that all frequencies beyond the
selected frequency are affected.
-15 +15
MF1 and MF2 affect the upper and lower mid frequencies respectively.
EQ IN
These have a peak/dip (bell shaped) response which means that the
maximum boost or cut occurs at the selected (center) frequency. The MF1
and MF2 bands overlap for additional cut or boost when required or to
provide a tailored frequency response to suit any application. The sharpness
of the curve is selected using the Q switch to a Q of either 1 (wide band) or
2.4 (narrow band).
warmth to the sound. Use narrow band to control problem frequencies for
example when notching out acoustic resonances.
20
- Feeds +48V to pins 2 and 3 of the input XLR for condenser
- Reduces low frequency source noise such as
Use wide band when you want to add presence or
Can also be effective in minimising

Use the
GL4800
User Guide