Maxx2 and Subwoofer?

[Mark Manner]

I have Maxx2s as my L/R 2 channel speakers (McI C50 pre/McI MC302 amp). I have them set up in a room with a home theater as well, and use them as the front L/R channel in 5.1 setup (rear/surr are Sophia2s, center channel a single Watt-3, sub a B&W). I am thinking of getting a better sub, and wondered if I should use the new sub with the Maxx2s for 2 channel music? I haven't been using the B&W sub for 2 channel, just HT. My question is whether the Maxx2's have any need for a separate sub. I am getting a MEN220, and could use the crossover in it to add the sub in. If I had the new sub, I would just try it an listen, but in part my decision to upgrade subs will be affected by whether I would want to use it for 2 channel as well. THoughts would be appreciated, including any recommendations for a sub. I would like to find a Wilson Watchdog, but I hear good things about the F113 as well.
Thanks,
Mark