I stuffed the M5s and the 160 with foam in my main room and cut all speakers to 80Hz. I'm even more close now to not needing Audyssey. I have a very narrow band somewhere down low I need to knock down.

Incidentally, even with the sphincters plugged, the Onk found all my speakers at 40Hz which I find very surprising.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated