Kurzweil FORTE SE Musician's Manual page 124

Note: For each note triggered, you can only set the controller value that will scale the
Depth parameter of an envelope section before that section of the envelope is triggered.
For controllers assigned for Attack, the controller value used will be the last received
before the note is triggered. For controllers assigned for Decay, the controller value
used will be the last received before the final section of the attack envelope reaches its
maximum amplitude. For controllers assigned for Release, the controller value used will
be the last received before the note is released. To put it another way, for each envelope
section, you cannot change the rate of a note's envelope once that section of the envelope
has been triggered.
Impact
Impact can boost or cut note volume by up to 24 dB during the first 20 milliseconds of the
attack of an envelope. This feature is an easy way to get more "thump" from your bass and
drum sounds.
Program Edit Mode
The Envelope Control (ENVCTL) Page
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