Ultrabeat envelope overview in MainStage

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.