I finally fixed the audio in the dome this evening. Tracking the issues down was hard enough. Three different 5.1/7.1 sources, a handful of stereo sources. Switched through an Extron 12:8 matrix (with an evil manual). Feeding two RME Firefaces, which via a physical modelling simulation, feed the 10 actual speakers.
Once I'd found a way to get a signal to a know channel in the Extron, is was pretty easy really - they're amazing devices, can even program in A/V delays. The rear has more BNC sockets than you've ever seen, so densly packed that they give you a special tool (that looks like a tool for taking test cores from cheese) to fit them...
