Wondering why your synth note sounds like a click instead of a pluck or a pad? An ADSR envelope shapes loudness over time with attack, decay, sustain and release; tweak those four controls and the sound changes character.
This guide is part of our sound design series.
| Stage | What it controls |
|---|---|
| Attack | Time from silence to peak, set in milliseconds |
| Decay | Time to settle from the peak to the sustain level |
| Sustain | A level, not a time: the volume held while the key is down |
| Release | Time to return to silence after the key is released |
| Example pluck | Attack 17ms, decay around 600ms, minimum sustain |
Figures come from Native Instruments’ ADSR guide and the Max Cookbook. Check those sources before you rely on them, as they can change.
What an ADSR envelope does
An envelope is a shape that plays out each time you press a key. According to Native Instruments, an ADSR envelope is “the most common kind of envelope found in synths and other tools such as samplers.”
Compared with oscillators and filters, envelopes don’t affect the sound directly; they control another parameter over time. That is why a single idea explains so many different sounds.
Most often the controlled parameter is volume. The same shape can also drive pitch or filter cutoff, so one set of four knobs can move loudness, brightness and tuning.
Think of it as a recipe for what happens between pressing and releasing a key. The oscillator supplies the raw tone, and the envelope decides how that tone arrives, lingers and leaves.
The four stages, one by one
Attack
Attack is a time value: how long the sound takes to climb from silence to its peak. Drum sounds tend to have a very short attack, while smoother, more atmospheric sounds such as synth pads have a longer one.
A very short attack gives a hard, percussive onset. Lengthening it slightly can tame sharp transients, and lengthening it a lot gives a swell, like a bowed string fading in.
Decay
Per Native Instruments, “Decay controls how quickly a sound dissipates after its initial impact.” It is the slope between the peak and the level you hold while the key is down.
Short decay times make a note feel tight and punchy. Longer ones let the note relax gently into its held level.
Sustain
Sustain is the odd one out. It is the only stage stated in volume instead of time, so it is a level you hold, not a duration.
The Max Cookbook describes the same model: a sustain level is “an amplitude factor, not a ms time”. Set sustain to zero and the note fades to silence during decay even while you keep holding the key.
Release
Release controls how long a sound takes to fade to silence after the key is released. A short release stops the note abruptly, which suits staccato bass lines.
A long release lets notes overlap and blur together, which is the washy tail you hear on ambient pads.
How the stages affect each other
The stages are linked, so adjusting one changes how the others behave. If sustain is at maximum, decay has no effect, since the volume has nowhere to go.
If sustain is at minimum, decay determines how quickly the envelope falls from its peak to silence while the key remains held. Release is also tied to the stages before it, since it starts from wherever the envelope is when you let go.
A practical way to work: set sustain first, because it decides whether decay matters at all. Then set attack for how the note starts, decay for how it settles, and release for how it ends.
Starting settings for common sounds
Native Instruments demonstrates a pluck with a short attack (17ms), a medium decay (around 600ms) and minimum sustain. Change only the envelope, and the same patch becomes a keys-style sound and then a smooth pad.
- Pluck: very short attack, medium decay, sustain at minimum.
- Keys-style tone: a quick attack with a moderate sustain so the note holds while pressed.
- Pad: slow attack, high sustain, longer release.
- Drums: very short attack; a slightly longer attack can tame sharp transients.
Treat these as starting points and adjust by ear, since every synth and every patch responds a little differently. Your oscillator, filter and playing style all change what sounds right.
When a sound feels wrong, name the problem in terms of stages. For a click at the start, check attack; for a note that dies too soon, check decay and sustain; for a tail that cuts off, check release.
Common mistakes and quick fixes
Most envelope problems come from one stage being set without thinking about its neighbours. These are the patterns worth checking first when a patch feels off.
- Raising decay while sustain is at maximum: nothing changes, so you may think the knob is broken. Lower the sustain first.
- Zero sustain on a pad: the sound fades while you still hold the chord. Raise the sustain level.
- Release too long on a fast bass line: notes smear together and the low end gets muddy. Shorten the release.
- Attack too slow on a rhythmic part: the notes arrive late and lose their groove. Shorten the attack until the beat feels locked.
Another habit that helps is changing one stage at a time and replaying the same short phrase. You hear the effect of each control in isolation, which builds a feel for the shape faster than random tweaking.
Also test with both short and long notes. A setting that works for a held chord may sound clipped on a quick run, because the envelope is released before the decay stage has finished.
Going further with envelopes
Route an envelope to filter cutoff and brightness will move with each note. In the Native Instruments example, the ADSR envelope is assigned to both amplitude and filter cutoff, so loudness and tone change together.
Try a fast filter decay on a bass for a snappy pluck, or a slow filter attack on a pad so the tone opens gradually. Using separate amplitude and filter envelopes gives you even more control, since each can have its own timing.
Envelopes also pair well with other techniques. Try shaping individual grains in granular synthesis, or give each part different shapes when layering sounds so every layer has its own movement.
Frequently asked questions
Is sustain a time value?
Show answer
No. Sustain is a level, while attack, decay and release are times. That is why it is the one knob measured in volume rather than milliseconds.
Why does my sound click at the start?
Show answer
A very short attack can create a sharp transient. Lengthening the attack slightly is one way to soften it.
What does decay do if sustain is at maximum?
Show answer
Nothing audible, because the volume doesn’t need to fall.
Can an envelope control more than volume?
Show answer
Yes. It can control many parameters in a synth or sampler, including pitch and filter cutoff.
