Those multi driver headsets are vastly inferior to PRIR HRTF binaural convolution. and no more externalized than things like dolby headphone, atmos for headphones, dts headphone x, sennheiser gsx, creative cmss or sbx, and honestly those hrtf renderers work better than the 5 discrete drivers in one earcup. Think about all the reflections from all those drivers in the ear cup. Perhaps with significant dsp to the individual drivers it could work better, but they act as discrete channels and thats counter to how are ears work, 2 ears to locate sound sources. Take stereo headphones and move them forward on your head a bit, there's your front/left right drivers, move them back and there's your surround drivers, does it actually sound like speakers out in front of or behind you? nope. Angling the drivers and moving them forward does improve the waveform, however, which improves soundstaging and imaging(i.e. Sennheiser HD800), but it still doesn't do what binaural rendering does.What about using/hacking the Razer Tiamat 7.1 headset? Real surround instead of virtual. Theoretically, its inputs could be connected to a receiver's speaker outputs, true? If course, the speaker output for the subwoofer is going to be line-level, so add one extra channel of amplification.
This tosses out the concept of wireless, but I would rather have good surround through a cable than lame surround wirelessly.
As far as hooking it up to an AVRs speaker outputs? I'm gonna go with no do not hook up 32ohm 20-40mm headphone drivers to speaker amplifiers. Maybe if your AVR has preouts for all channels this could work.
Its an interesting idea though ;]