Dave Smith Instruments Sequential PROPHET X, User Manual, Page: 49 / 172

37 Prophet X User’s Guide Filter Envelope
Filter Envelope
The Prophet X filter has a dedicated, 5-stage envelope generator (ADSR
plus delay). The Filter Envelope is used to shape the harmonic charac-
teristics of a synthesized sound by giving you filtering control over its
attack, decay, sustain, and release stages.
This is one of the most important aspects of designing a sound. Without
an envelope, the filters would be completely static. They would stay open
or closed by a fixed amount that wouldn’t change over the duration of
a sound. That’s not very interesting to listen to and not how real-world
instruments behave.
In general, sounds produced by an instrument are brighter at their begin-
ning (the attack stage) and grow mellower as they die out (the decay and
release stages). In other words, their harmonic content changes over time.
This is exactly what the filter envelope is designed to emulate.
Filter Envelope
attack decay sustain release
amplitude
time
note off note on
delay
A typical 5-stage DADSR envelope