User manual

limiter to the clipper or saturator, which causes more distortion of the initial transient, but less pumping.
In a gate the situation is similar to a compressor - attack time controls how quickly can the level get above the threshold
where the gate opens. In this case you will usually need very low attack times, so that the gate reacts quickly enough.
The inevitable distortion can then be avoided using look-ahead and hold parameters.
In a modulator, the detector is driving other parameters or a filter for example and the situation really depends on the
target. If you want the detector to react quickly on the input level rising, use shorter attack times. if you want it to slowly
follow flow of the input signal, use longer attack and release times.
Release
Release defines the release time, thus how quickly level detector decreases the measured input level. The shorter the
release time, the faster the response is. When the input peak level is higher than current level measured by the detector,
the detector get into the attack mode, in which the level is increasing depending on the input signal. The higher the input
signal is, the faster the level rises. And also the shorter the attack time, the faster the level rises.
There must be a reasonable balance between attack and release times. If the attack is too long compared to release, the
detector would tend to keep the level low, because release would cause the level to fall too quickly. Hence in most cases
you may expect the attack time to be shorter than the release time.
To understand the working of a level detector, it is best to cover the typical cases:
In a compressor the release time controls how quickly can the level fall below the threshold and the compression stops.
As a result a very short release time makes the compressor stop quickly leaving the sustain of a snare drum for example
intact. A very long release other hand keeps the compression working longer, hence it is useful to stabilize the levels.
In a limiter the release time keeps the level above the limiter threshold causing the gain reduction. Having a very long
release time in this case doesn't make sense as the limiter would be working continously and the effect would be more or
less the same as simply decreasing the input gain manually. However too short release time lets the limiter stop too
quickly, which usually causes distortion. Hence release time is used to avoid distortion at the expense of decreasing output
level.
In a gate the situation is similar to a compressor - release time controls how quickly can the level fall below the threshold
where the gate closes. Since ear response better to the attack and sustain is masked by the initial transient, having longer
release time in a gate is a perfectly acceptable option. The release time will basically control how much of the sound's
sustain will pass.
In a modulator, the detector is driving other parameters or a filter for example and the situation really depends on the
target. If you want the detector to react quickly on the input level falling, use shorter release time.
RMS length
RMS length smoothes out the input, so the level detector gets already preprocessed signal without so many fluctuations.
With minimum value this becomes a so-called "peak detector", otherwise it is an "RMS detector".
When you look at a typical waveform in any editor, you can see that the signal changing a lot and contains various
transient bursts and separate peaks. This is especially noticeable for rhythmical signals, such as drums. Trying to think how
a typical attack/release detector works with such a wild signal may be complex, at least. RMS essentially takes surrounding
samples and averages them in a way. The result is much smoother signal with less individual peaks and short noise bursts.
RMS length controls how many samples are averaged. It stabilizes the levels, but it also causes slower response. As such it
is great for mastering, when you want to lower the dynamic range in a very soft way without any instabilities. However it
is not really desired for processing drums for example, where the transient bursts may actually be individual drum hits,
hence it is usually recommended to use peak detectors for percussive instruments.
Note that the RMS detector has 2 modes - a simplified approximation is used by default, and a true RMS is processor can
be enabled from the advanced settings (if provided). Both respond differently, none of them is better than the other, they
are simply different.
Peak hold
Peak hold defines the time that signal level detector holds its maximum. You can imagine that when an attack stage ends,
before the release stage starts, there can be an additional peak hold stage and the level is not falling yet. This is true only
when true peak mode is enabled (check advanced detector settings if available).
It is often used in gates to avoid the level falling below the threshold too quickly, while having short release times. If you
want the gate to close quickly, you need a short release time. But in that case the ending may be too abrupt and even
cause some distortion. So you use the peak hold to delay the release stage.
It is also used along with look-ahead to avoid distortion in limiters and compressors. If you need a very short attack,
the attack stage may be too quick and cause distortions. In limiters this attack is often 0ms, in which case it becomes a
clipper. Setting look-ahead and peak hold to the same value will make the detector move ahead in time, so it can react to
attack stages before they actually occur and yet hold the levels for the actual signal to come.