If you have a processor and outboard amp(s) you could use an Outlaw ICBM bass management unit, set all your speakers to "large," and set the cross over point for each channel independently using the ICBM. I'd try 80Hz for the M60s/M80s/ 100-120 Hz for the QS8s and M2is. Sounds very good!

Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.