ADSR envelopes
An envelope describes how a parameter changes over time. In a common amplitude-envelope model, attack is the rise after a note starts, decay is the move from the initial peak toward a held sustain level, and release is the fade after the note ends. Sustain is a level, not a duration. Instruments may label or implement these controls differently, and envelopes can control other parameters such as filter cutoff when routed that way.
Optional visual experiment: the envelope shape
Change one control at a time and watch which segment moves. Attack, Decay and Release are shown with illustrative time ranges; Sustain is a relative level. The chart uses a fixed note-held interval of 800 ms to show the sustain level before note-off. That interval is only part of this drawing: Sustain does not set its duration.
Optional visual experiment
Shape a simplified envelope
Change one control and follow the line. The note-held interval stays fixed so Sustain is shown as a level, not a duration.
Amplitude level over time — envelope shape, not an audio waveform
- 01Attacktime to peak
- 02Decaypeak to sustain
- 03Sustainlevel while note held
- 04Releasetime after note-off
Current model
The envelope rises to its peak over 100 milliseconds, then decays to 60% over 300 milliseconds. It stays at that level during a fixed 800 millisecond displayed note hold, then releases to zero over 500 milliseconds after note-off.
The chart holds the note for a fixed 800 ms. That display interval is not controlled by Sustain.
Model boundary: This visual uses straight-line segments in one simplified amplitude-envelope model. Synthesizers may use different ranges and curves, and envelopes can control parameters such as filter cutoff instead of amplitude.
Before changing a control in your DAW, predict what the matching envelope setting will change. Then try it on a held note if your instrument exposes that control, listen to the result, and compare it with the prediction. This visual is a simplified model; use listening to explore how your instrument behaves.
LISTEN
Compare a short, plucky sound with a slower, pad-like sound on the same held note. Notice how quickly each begins and how it ends. The sounds may differ for reasons beyond their envelopes; focus on the audible start and tail.
TRY
If your instrument exposes an amplitude envelope, make one version with a quick attack and short release, then another with a slower attack and longer release. Change one control at a time. If those controls are unavailable, compare built-in sounds with different obvious starts or tails and describe the same behavior without editing a synth.
Optional BandLab reference: BandLab’s instrument guide describes attack and release controls on customizable Membership instruments; fixed-parameter instruments may not expose them. Use a built-in contrasting sound or another DAW’s instrument without requiring Membership. Using BandLab Virtual Instruments.
APPLY
Choose an envelope behavior that fits one part’s musical role—for example, a defined onset or a gradual entrance. Compare the original and changed version in context. If the instrument does not expose ADSR, selecting a suitable sound is a valid application.
Technical reference: Ableton Live Manual: Live Instrument Reference gives an example of ADSR amplitude and modulation envelopes; other instruments differ.