Playback audio routing with Audiofire 12

Not a Hauptwerk-dedicated question, but I'm hoping someone will be able to help with some advice.

I have an Audiofire 12 connected by firewire to a MacPro. This gives great multichannel routing when playing Hauptwerk live. But I also want to use more than one pair of speakers when playing back audio (like a Hauptwerk recording, but also CDs and eventually phono). I can't work out how to do this on the Mac, despite investigating the Audio setup screens, AU Lab, Soundflower, even tried via Reaper. So far, the best I've managed is to play a single audio track back through multiple speakers using AU Lab and its built in AUAudioFilePlayer, but that means entering each file separately into the Player, when I just want to set the thing up permanently to playback through more than one pair of speakers.

Any tips?

Best wishes,

Geoff

After a bit more experimenting, I see there is an option in Reaper (admittedly marked 'not recommended', but seems to work OK) to specify different input and output sound devices, and this allows you to use Reaper to route audio out through multiple channels of the Audiofire 12 while specifying different input devices for eg CDs or phono.

Best wishes,

Geoff