I think we can describe mute groups in terms of two simple scenarios:
- The classic usage case, in which a drumkit has an open and a closed hihat. The open hihat can be triggered, and will play - with a release that determines for how long. Once the closed hihat is triggered, the open hihat will immediately stop playing, as it is essentially the same sound source, and can only be in one state at a time (open OR closed).
- Having a bunch of loops which are grouped logically in pairs - e.g. loop 1 & 2 and loop 3 & 4. Triggering any of these loops would make the sample play indefinitely - not being released, ever. But triggering another loop in the same group will cause the new loop to play instead (also indefinitely).
For (1), there seem to be some bug that causes the samples to be cut of when the open hihat is released before triggering the closed one. Other than that, I believe it’s working as it’s supposed to.
For (2), the sample’s NNA setting could be put to good use (“continue”), this could be used for triggering samples that never reach the release stage. Right now, we can do something similar for an instrument by enabling both “mono” and “hold”, but it’s too simplistic as it doesn’t involve mute groups.
For both cases, I think it’s good to have the NNA value affect the behavior - you can define a normal ADHSR for the open hihat, to make it sound realistic when played on it’s own, but the NNA can be set so that the instrument is immediately cut off when the closed version is triggered. And for the looped beats, the NNA = continue will enable endless playback without resorting to workarounds using modulation envelopes (and the mute group itself will preventing multiple loops from playing on top of each other).
As for the polyphonic limit of an instrument - this is also being discussed over here:
http://forum.renoise…g-release-times