setVolume
Sets the volume, from silence at 0 to unity at 1, and up to AudioConfig.volumeCeiling when that has been raised to allow a boost.
Applied as one multiply per sample as frames leave the ring, over a short ramp, so a change never clicks and is audible within one device period. Above unity each sample is folded through a saturator rather than allowed to clip, so a boosted loud passage compresses instead of squaring off; at or below unity nothing is folded.
The ceiling is 1 by default, which refuses every boost: amplifying without being asked is not a player's decision. Raise AudioConfig.volumeCeiling to offer one.
Throws
when value is not finite or is outside 0 to the ceiling.