Low Cut Switch
To remove excessive bass from an individual channel, press the Low Cut Switch (1) for that channel.
15
The
Compressor/Limiter
(1) is a dynamic range controller that can be used to compensate for signals
that may sound unnatural or cause audible distortion. This is indicated by the LED Bar Graph Output
Meter (3) occasionally exc12 VU (red).
Note:
The Compressor/Limiter only affects the main channel.
A Compressor is used to slightly reduce the dynamic range of a signal. This effect is perceived to quiet
loud sounds and boost quiet sounds. A compressor smooths transients.
A Limiter is used to prevent a signal from exceeding a certain level. This function guards against amplifier
or recording level overloads. The Compressor/Limiter is activated by pressing the Main Output Compre
-ssor/Limiter Switch.
This dynamic controller allows for compression and limiting functions by controlling threshold and ratio.
The
Threshold Control
(2) is a screw potentiometer that sets what signal level will activate the
Compressor/Limiter. It has a range of -20 to +20 dB.
The
Ratio Control
(4) is a screw potentiometer that sets the compression ratio that will be applied when
the signal exceeds the threshold. It has a range from 0% to 100%. A Compressor becomes a Limiter
when the compression ratio is 10:1 or greater.
The factory setting for the threshold is 0 VU (+4 dB), but this is variable (from -20 dB to +20 dB) and can
be changed by adjusting the Threshold Control. Likewise, the factory setting for the compression ratio
is 100% (at this maximum setting, the circuit performs the limiter function), but can be set to between 0
and 100% by adjusting the Ratio Control.
Note
: The LED Bar Graph Output Meter can be used to view the effects of adjusting the Compressor/
Limiter controls. Turn off power amplifiers while performing these adjustments.
Warning
: If the amplifier/speaker combination being used is such that the speaker(s) can be overdriven
to failure, always operate the mixer with the Output Limit Switch in the
"
on
"
position and the ratio should
be set at 100%.
MAIN
LIMIT
THRESHOLD
RATIO
ON
OFF
-18 -12 -6
-3
0
+3 +6 +12
-20
+20
100
0
2
4
1
3
5.4 Compressor/Limiter
OPERATION
