User Manual

24 Filter Envelope Dave Smith Instruments
Filter Envelope
The Prophet Rev2 lter has a dedicated, ve-stage envelope generator
(DADSR). The Filter Envelope is used to shape the harmonic charac-
teristics of a synthesized sound by giving you ltering control over its
attack, decay, sustain, and release stages (plus a delay parameter to delay
the onset of the envelope).
This is one of the most important aspects of designing a sound. Without
an envelope, the lters would be completely static. They would stay open
or closed by a xed amount that wouldn’t change over the duration of a
sound. That’s not very interesting to listen to and it’s not how instruments
behave in the real world.
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 lter envelope is designed to emulate.
CUTOFF RESONANCE ENV AMOUNT VELOCITY KEY AMOUNT AUDIO MOD
4 POLE DELAY ATTACK DECAY SUSTAIN RELEASE
LOW-PASS FILTER
Filter Envelope
Attack Decay Sustain Release Delay
Amplitude
Time
note on note off
A typical 5-stage DADSR envelope