Hello Dharmatone
I used a pair of M22s and M22 like Michaura M55s in my stereo system. I had an 8" Velodyne (CHT80) which was quick and musical but didn't go much below 35Hz. I just picked up a subwoofer kit from partsexpress.com, the Vance Dickason 10" Titanic, put it together (a no brainer - the cabinet is already constructed, you just have to put in the damping material, screw in the driver and the amp. This amp is very, very impressive. Tight, fast and musical. Goes way down. No chuffing, no rumbling, just sounds like the M22 like speakers go all the way down to about 20-25Hz. Cost was $350 delivered.
I have a bunch of other subs around the house and office in various systems, including a 1640 watt Klipsch LF10, a Dahlquist PDQ1500 15" sub, a 10" Velodyne CHT100. The Vance Dickason kit sub may be the best of the bunch.
BTW, on my stereo system, I listen mostly to jazz, female vocals, Celtic crooning (Loreena McKennett) and Clapton like blues/rock. Sounds terrific. You'll love the M22s they are great speakers, but do need a bit of help down low.
