I recently purchased a FireStudio Project and an HP60 to live record a band. I have had no issues with recording into the FireStudio or with basic monitoring with the HP60. However, I cannot seem to use the 'more me' (Ext/Aux in) function. Whether it be playing back audio tracks or live monitoring, the Ext. In knob does nothing other than feed the exact same master signal as the 'output A' knob from the stereo main outputs on my FireStudio. I have seen the wiring diagram provided with the manual and tried my best to replicate it, although that doesn't help much. I am using Logic Pro X as my DAW.
for reference, I have my hardware wired like this with TRS patch cables:
FireWire cable from Mac>FireStudio>FireStudio Main outs Left and Right>HP60 Input A Left and Right
FireStudio general output 1>HP60 Stereo Ext. In 1
FireStudio general output 2>HP60 Stereo Ext. In 2
I have also messed about with the Universal Control, but this may have only confused me more.