Sean, welcome. If you happen to already have a MX-2000 and just want to give it something to do, that might not be a bad idea. However, the Z-9 is a very powerful receiver(note the results, including 4 ohm, in the Audioholics test ) and should handle the M80s and other speakers with ease in most setups. If you don't have the Z-9 now, there are of course other receivers that also can do the job.

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Enjoy the music, not the equipment.