Compressor/Limiter; Expander/Gate - Calrec SUMMA User Manual

Threshold
Ratio
Attack
Release
Make Up Gain
Hard, 0.4 dB, 0.8 dB, 1.5 dB, 3.6 dB, 12 dB, 24
Knee
Threshold
Depth
Attack
Release
Knee Variable soft knee or 2:1 hard knee
Threshold
Depth
Attack
Release
Delay

Compressor/Limiter

Compressor/limiters provide controls for reducing and smoothing the dynamic range of an audio signal. Compressors
proportionally reduce the gain of a signal as it exceeds a definable threshold. When the compressor is set to be a limiter
(by selecting a ratio of 50:1), the input signal must increase by a massive 50 dB above the threshold in order for the
output to increase by a negligible 1 dB.

Expander/Gate

An expander acts in the opposite way to a compressor: When a signal exceeds the expander threshold it is passed
through unchanged, and when it falls below the threshold it is reduced, effectively increasing the dynamic range of the
signal and reducing unwanted audio content.
CALREC
Putting Sound in the Picture
Compressor
-48 dBFS – 0 dBFS
1:1 to 4:1 in steps of 0.1
4:1 to 10:1 in steps of 0.2
10:1 to 20:1 in steps of 1
20:1 to 40:1 in steps of 5
50:1 (Limiter)
50 µs – 0.2 s
Auto, 75 ms – 4 s
0 dB – 20 dB
dB
Expander
-60 dBFS – -6 dBFS
40 dB – 0 dB
50 us – 0.2 s
0 ms – 4 s
Gate
-60 dBFS – -6 dBFS
40 dB – 0 dB
50 µs – 0.2 s
0 ms – 4 s
0 ms – 1 s
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