ADSR is an absolute essential. It allows you to change the shape of a sound, effectively changing how the sound develops. If you don’t know what ADSR stands for, don't worry! The Soundpaint Part ADSR Rack can help you out:
ADSR (Attack, Decay, Sustain, Release) affects the envelope of a sound. With the exception of Sustain, these controls all control the time it takes for the sound to do something.
Attack is the time it takes for a sound to reach its maximum level after being triggered. A higher attack time will make the sound fade in slower. A higher attack can be great for slower pads, and a low attack can make synth stabs and staccatos really precise and sharp. An attack of 0 can sound a bit unnatural or abrasive at times, so low values that aren’t quite 0 might be more effective, depending on the instrument.
Decay is the time it takes for the sound to decrease from its maximum level to the sustain level. This can be a bit confusing without explaining what Sustain does, so…
Sustain is the level at which the sound holds after decaying. A value of 1 (the maximum) means that the sound will sustain at its full volume until the key is released; this also means that the decay time effectively does nothing (if a sound is decaying from 100% to 100%, the time it takes to do so is meaningless). This can still be a bit confusing, so we’ll take a closer look after we explain…
Release is the time it takes for the sound to fade out to zero after the keys have been released - essentially the opposite of attack. A high release time will sound like a long fade out, which again could be useful for pads. Also like attack, a release of 0 will sound sharp, but also pretty unnatural (especially if there is no reverb anywhere). An immediate-release sound can still be useful, but at least a short release may sound more natural in general.
So that’s the basics of the sound envelope. Remember, the Rack module can change ADSR for each part individually, or you can link them all together.
Before we finish today's ADSR discussion, let’s try to visualize the envelope
This chart shows an envelope where the Sustain is set to about 0.5, with a moderately long attack, decay, and release.
First, the sound attacks to the peak, then decays to the sustain level. It holds at this level until the keys are released, and then fades back to 0 with a moderately long release.
By contrast, the following chart shows an envelope where the Sustain is set to 1, so there is no change between the initial attack and the sustain level
This represents a more “default” kind of sound. If you wanted a similar effect where the initial attack is a little louder, you could control the levels manually with dynamic sustains, too. If you wanted to create a kind of marcato sound, you could set the attack and decay to be pretty short, with the sustain a bit lower.
Of course, there’s only so much explaining it will do. If you’ve never experimented with ADSR, give it a shot yourself and see what kinds of sounds you can make!
This was a lot of information, but our ADSR discussion isn’t completely over…
But we’ll save that for next time.