nad m25

Could a nadm25 drive b&w801diamonds ?
A mismatch IMO

These speakers are usually mated with kit a lot higher on the $$$$ food chain. By extension the source and cables follow lockstep.
Yes, the M25 could easily drive the B&Ws with very satisfactory results. 801s like to see a lot of current and the NAD provides that in spades.

Despite Akg_ca's protestations, it isn't a matter of $$$, it is a matter of being electrically correct. The NAD is electrically correct...