Opto Compress - Kurzweil K2661 Musician’s Reference Manual

Maximum
Magnitude
L Input
R Input
Figure 102

Opto Compress

The soft-knee compressor is used which has a more gradual transition from compressed to unity gain.
Figure 103 Soft-Knee compression characteristic
For typical compressor behavior, the attack time is considerably shorter than the release time. At very
short attack and release times, the compressor is almost able to keep up with the instantaneous signal
levels and the algorithm will behave more like distortion than compression. In addition to the attack and
release times, there is another time parameter: SmoothTime. The smoothing parameter will increase both
the attack and release times, although the effect is significant only when its time is longer than the attack or
release time. Generally the smoothing time should be kept at or shorter than the attack time.
You have the choice of using the compressors configured as feed-forward or feedback compressors. For
feed-forward, set the FdbkComprs parameter to Out; for feedback compression, set it to In. The feed-
forward configuration uses the input signal as the side-chain source. The feedback compressor on the
other hand uses the compressor output as the side-chain source. Feedback compression tends to be more
subtle, but you cannot get an instant attack.
In the feedback configuration, the signal being compressed may be delayed relative to the side chain
compression processing. The delay allows the signal to start being compressed just before an attack
transient arrives. Since the side chain processing "knows" what the input signal is going to be before the
main signal path does, it can tame down an attack transient by compressing the attack before it actually
happens.
A meter is provided to display the amount of gain reduction that is applied to the signal as a result of
compression.
Compressor
Computations
Delay
Delay
Out
Amp
In Amp
Maximum
Magnitude
Compressor
Compressor
Threshold
KDFX Reference
KDFX Algorithm Specifications
L Output
Out Gain
R Output
10-197