User Manual

22 Filter Envelope Dave Smith Instruments
Filter Envelope
The OB-6 lter has a dedicated, four-stage envelope generator. The Filter
Envelope is used to shape the harmonic characteristics of a synthesized
sound by giving you ltering control over its attack, decay, sustain, and
release stages.
This is one of the most important factors in 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 instru-
ments 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.
FILTER ENVELOPE
ATTACK DEC AY SUSTAIN RELEASE AMOUNT
VELOCITY
ENVELOPES
Filter Envelope
Attack Decay Sustain Release
Amplitude
Time
A typical 4-stage envelope