Can I use Tritonus to play back on multiple devices simulaneously?
Yes, if you are using Linux. In this case, install ALSA and use the ALSA plugin from Tritonus Plug-ins. (If you are on an x86 architecture. Otherwise you have to compile Tritonus yourself.) If you are using a different UNIX-like system, you may try with running multiple Esound instances. However, this looks quite tricky to me. I’ve never tried it.