Well, I'd ALSO advise some personal listening in your room.

Since I rarely listen very loud, I found that running M60's full-range (or with a 60Hz crossover), IN MY ROOM was very helpful in eliminating room-related bass nulls in the 60-80Hz region. Having the extra transducers in different locations was of more value to me than the extra headroom. YMMV.

Try it a few different ways and do whatever sounds best to your ears in your room.

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