10.6

591Logic Pro Instruments
Logic Pro Ultrabeat envelope overview
Ultrabeat features four identically specified envelope generators per voice. They are
abbreviated as Env1 to Env4. In addition to potential use as a modulation source (in the
mod pop-up menus of various sound parameters), Env4 is permanently connected to the
Voice Volume parameter. In other words, each Ultrabeat drum sound has a hard-wired
volume envelope generator—Env4.
See Attack, decay, sustain, and release for information on the roots of the term envelope
generator and its basic function.
The default behavior of the envelope generators is known as the one-shot envelope mode:
after a key is pressed (note-on message), the envelopes run their course, regardless of
how long the note is held. This setting is ideal for percussive signals, because it emulates
the natural behavior of acoustic percussion instruments.
For special cases, such as sustained pad or cymbal sounds, you can activate a sustain
mode where the envelopes take the lengths of the played notes into account.
The envelope display provides a unique envelope design, consisting of Bezier curves in
which two segments—attack and decay—constitute the entire envelope.
In the envelope graphic, you can see various handles (junction points) of two different
sizes. Drag these handles to adjust the envelope shape.
Both of the larger handles on the x-axis (the horizontal, or time axis, at the bottom) control
the attack and decay times, respectively. A vertical line extends up from the first of the two
handles (attack), and divides the envelope into an attack and decay phase.
Both segments have two small curve handles. You can drag these in any direction to
deform the contour of the envelope and shape its amplitude.
You can also directly drag anywhere on the curve itself to reshape the envelope.