Ensemble FireWire doesn’t show up in my audio program or in Audio MIDI Setup.

Verify that the required version of OS X is installed. Verify that Ensemble’s STATUS LED is solid blue. Check to see if the Ensemble shows up in the Apple System Profiler. You can check this by going to the Apple menu, choosing About This Mac and clicking on "More Info...". Click on FireWire under the Contents column on the left to make sure the Ensemble is recognized by the Mac.