User Manual

31
Gain Reduction Meter
This is a 10-segment LED bargraph meter indicating the amount
of gain reduction. Due to the scale of the meter, sometimes you
willonlywanttherstfewLEDsickeringtokeepcompression
to musical levels on the mix bus.
The scale on the gain reduction meter ranges from 2dB to 20dB
of compression.
Compression Ratio
Speciedasaratioof input vs output (in:out), the ratio control
sets how much compression takes place once a signal has
crossed the threshold point set in the sidechain circuitry.
A ratio of 2:1 indicates that when an input signal crosses the
threshold by 2dB, an increase of only 1dB would be present
at the output, thus 1dB of gain reduction would be produced.
Generally, low ratios such as 1.5:1 and 2:1 are used over the
main mix bus, but feel free to experiment. As the ratio increases,
the compressor acts more like a limiter (10:1 and 20:1) and can
be very useful or powerful on dynamics sources such as drums
or vocals. The soft knee design provides a gradual entrance to
compression from below the threshold, and is very smooth.
Ratios can be set to:
•
1.2:1 (very gentle)
•
1.5:1
•
2:1
•
4:1
•
10:1
•
20:1
Attack Time
Speciedinmilliseconds(ms),thisisthetimetakenforthe
compressor sidechain to react to the input signal above the
threshold and trigger gain reduction (compression).
Attack times can be set to:
•
0.1ms
•
0.3ms
•
1ms
•
3ms
•
10ms
•
30ms
Typically on program material and mix bus use, slower attack
times (try 10 or 30ms for a punchy starting point) are preferred
astheywillnotmangletransientmaterialordistortlowfrequency
content as much as faster times.
If the attack or the release time is faster than one cycle of the
lowestfrequencytobereproduced,distortionwilloccurasthe
compressor will alter the waveshape during one cycle.
Remember that the period of one cycle, T(sec) = 1/f (Hz).
The following diagram illustrates typical waveshaping at 60Hz
(approximately 17ms period) as created by relatively fast attack
and release times (10ms attack, 0.1 sec release at 4:1). Note
that aside from some attack waveshaping, the Control 2802
compressor is very clean!
Release Time
Speciedinseconds(s)–thisisthetimetakenforthe
compressor sidechain to release from gain reduction once
the input signal has passed below the threshold.
Release times can be set to:
•
0.1 sec (100ms)
•
0.3 sec (300ms)
•
0.6 sec (600ms)
•
1.2 sec
•
2.4 sec
•
Auto Release
Typicallyfasterreleasetimesarerequiredwhenyouwantthe
compressortogetoutoftheway“quickly”whichcanleadto
pumping and very obvious compression.