After lots of crashes and frailties, I got today the solution for an audio-cycle-buffer (2047 samples). That means, it is possible to synthesize custom sounds and effects nearly in runtime (delay about 47ms). I have no *BIG* example here right now. Just the first running engine. It has a simple SWF embedded, where an empty wavfile is exported. This SWF will be parsed, modified and reloaded to create the sync- and the permanently changing cycle-buffer-sound. The class Cycle provides switching mono/stereo and 8bit/16bit, yet.
Sidenote to Frank: It’s on you to bring the Roland TB-303 to Flash :-) And I have to mention e-phonic and david. They also tried to find a solution on dynamic sound synthesis in flash with pretty cool results.
To have a stable sync in the browser I had to double the cycle-buffer. So the latency is now about 92ms.
Update 1.5 years later the Hobnox AudioTool with lots of plugins is available.