Sound Parameters – Envelopes107 Waldorf Q User’s ManualADSR EnvelopeMost traditional synthesizers feature ADSR envelopes. These envelopes are made up of fourparameters that determine their response: Attack, Decay, Sustain and Release. The followingpicture illustrates the structure of an ADSR envelope:Attack DecaySustainReleaseKey pressed Key releasedTimeLevel100%Picture 39: ADSR EnvelopeThe envelope is started by pressing a key. It ascends to its maximum value at the rate determined bythe Attack parameter. It then descends at the rate determined by the Decay value until it reaches thepredetermined Sustain value. It remains at this value until the key is released. The envelope thendescends to zero at the rate determined by the Release parameter.Attack0…127Determines the attack rate or amount of time it takes for a signal to go from zero to maximum level.Decay0…127Determines the decay rate or amount of time it takes for a signal to reach the Sustain level.Sustain0…127Determines the sustain level which is held until a note ends.Release0…127Once the note has ended, the release phase begins. During this phase, the envelope fades to zero atthe rate determined by the Release value.
