Best sub match for Magnepan 3.5's


I am looking for the best sub match for my 3.5's. Size and price are not a concern, but I am looking for something powered and that can go low. I currently have a Conrad Johnson ART 15 preamp, a Conrad Johnson MF2200 amp, and I am going to use a Bryston 10B active crossover. Any suggestions would be helpful. Thanks.
tonythetaxman
Try asking this over at MUG a lot of folks are running subs and they have lots of experience with it, you may be able to search this topic and find a lot of information quickly. I believe a lot of them are using Rel subs and love the results, but check and see if there's a new favorite- I don't keep up to date with subs.
I am running a pair of Vandersteen 2wq's with my 3.6's. The sound is satisfactory. I think the bottom lacks a touch of definition that one can hear on large full range speakers such as the Soundlab electrostatics but, this could be true with other subs as well when mated to the Maggie 3.6's. I have not tried others so can not make comparative comments. But I am thinking about an REL......
I'm using a Rel Strata III with Magnepan 1.6QR's.
Excellent match, easy to configure.