Ok so its a bit of a cheat, but it does work! Try the webplayer. Ive tried what seems like a million ways to get realtime audio sequencing in unity. Unity isnt very good for small MS callbacks, it wont give access to fmods callbacks and all manner of timers (threads, coroutines,system timers) have lag and variable results when down to audio MS range. Probably only hardware bound callbacks (ie buffer requests from audio cards) are accurate enough. However, with some sneaky tricks Ive managed to get triggers to work down to a acceptable range. Heres the trick ,just in case anyone else has struggled with this. Run one sample on loop as a metronome. Run a fixedupdate (or any fast thread) and use this to find the current PCM sample pos of the metronome. Use this position to detect if the current loop of the metronome sample is nearing its end (the margin you can detect depends on the frequency of your fixedupdate etc). If its close enough to the next loop then trigger a new sound to play (and stop checking ).. BUT offset it by the remaining samples in the current loop (loop sample length- current sample position). This means it will play on the exact loop point that is coming up. This solution might not work for super slow machines and it less accurate as your tempo increases (but you can adjust the margin for that) but its the best, rather only solution ive found so far. enjoy!