Dave, there's no question that the M80s can take many hundreds of watts, but that your hearing can't(that may be what's "killer" about what you propose). 200 watts make a bit less than 3dB of difference in maximum loudness compared to 110. You should consider not less than 500 watts to accomplish your purpose.

Incidentally, if the sound levels between subs and speakers are properly calibrated by your receiver, they can't get "unbalanced", and it doesn't depend on the number of drivers.

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Enjoy the music, not the equipment.