I recently had to move my system to a smaller room and, in order to have enough space behind my M60s, was somewhat forced to place them/me such that I sit at the apex of a 7ft equilateral triangle. I honestly prefer this setup to my previous one (sitting about 10ft out, in an isosceles triangle), but I think you're fine at 9.5ft. Experiment, if not with seating position then with distance to the rear of the M60s.

Yeah, a bit late.

Jon

Axiom M60ti Hsu VTF-2 Mk2 NAD C320BEE NAD C542 Systemdek IIX Cables by Unity Audio