I can offer no better advice than what has already been given.
But I will point out that M80's are 4-ohm speakers. You probably knew that. Are you sure that your 94TXH can handle 4-ohm speakers? Being that's it's Pioneer's flagship AVR, I'd bet money that it *can*, but it's possible that it can't.
I am currently still using a Pioneer Elite 43TX as a prepro. It is at least 2 (3?) generations older than your 94, so it's nowhere near as modern and nice as what you have. But it was a $1,500 AVR in its heyday too, and it has been my experience that my 43 cannot effectively power my M80's at loud (>90db) volume levels, especially when running in full-range mode. An amp that was rated to handle 4-ohm speakers was required.
