User Manual

CHAPTER 21. LIVE AUDIO EFFECT REFERENCE 285
maximizing tool in the master channel. Less is often more here.
Because compression reduces the volume of loud signals and opens up headroom, you can
use the Output slider so that the peaks once again hit the maximum available headroom.
The Output meter shows the output signal's level. Enabling the Makeup button below the
Output slider automatically compensates the output level if the threshold and ratio settings
change.
The Attack and Release controls are essential parameters for controlling the response time
of Compressor by dening how fast it reacts to input-level changes.
Attack denes how long it takes to reach maximum compression once a signal exceeds
the threshold, while Release sets how long it takes for the compressor to return to normal
operation after the signal falls below the threshold.
A slight amount of attack time (1050 ms) allows peaks to come through unprocessed,
which helps preserve dynamics by accentuating the initial portion of the signal. If these
peaks cause overloads, you can try shortening the attack time, but extremely short times
take the life out of the signal, and may lead to a slight buzziness caused by distortion.
Short release times can cause pumping as the compressor tries to gure out whether to
compress or not; while generally considered an undesirable effect, some engineers use it
on full drum kits to give unusual sucking effects. Careful adjustment of attack and release
times is essential when it comes to compression of rhythmical sources. If you are not used
to working with compressors, play a drum loop and spend some time adjusting Attack,
Release, Threshold and Gain. It can be very exciting!
A compressor can only react to an input signal once it occurs. Since it also needs to apply
an attack/release envelope, the compression is always a bit too late. A digital compressor
can solve this problem by simply delaying the input signal a little bit. Compressor offers
three different Lookahead times: zero ms, one ms and ten ms. The results may sound pretty
different depending on this setting.
Compressor can be used in three different EF (envelope follower) modes. With Peak se-
lected, Compressor reacts to short peaks within a signal. RMS mode causes Compressor
to be less sensitive to very short peaks and compress only when the incoming level has
exceeded the threshold for a slightly longer time. Opto mode results in a non-linear release
curve. Specically, the release behavior is faster initially, and slows down as the gain reduc-
tion approaches zero. So which type should you use? There's no right answer, of course,
but there are some common uses for each mode. Peak mode is more aggressive and pre-