Owner`s manual

Attack and Release Times

The attack time of a compressor is how long it takes for the compressor to

react once the input level has met or exceeded the threshold level. With a

fast attack time, the signal is brought under control almost immediately,

whereas a slower attack time will allow the start of a transient or a

percussive sound to pass through uncompressed before the processor

begins to react.

For sounds without percussive attacks (voices, synth pads, etc.), a fairly

short attack time is usually used to ensure even compression. For instru-

ments with percussive attacks (drums and guitars, for example), a slower

attack time is typically used to preserve the attack transients and, hence,

the characteristic nature of the instruments.

The illustration below shows the effect of various the attack times.

The release time of a compressor is the time it takes for the gain to return

to normal after the input level drops below the threshold. A fast release

time is used on rapidly varying signals to avoid affecting subsequent

transients. However, setting too quick a release time can cause undesirable

artifacts with some signals. On the other hand, while slower release times

can give a smoother effect, if the release time is too long, the compressor

will not accurately track level changes in the input. Slow release times may

also result in audible level changes known as “pumping.”

UNCOMPRESSED INPUT COMPRESSED

1 mSEC ATTACK

COMPRESSED

10 mSEC ATTACK