Magnepan 20.7 and Subs

I've been reading about supplementing my Magnepan 20.7s with a sub, the general preference being REL.  However in room I'm getting fairly deep bass with the 20.7's, so my sense is that I would put the crossover on the REL pretty low, probably at 30Hz, leaving only sub 30Hz material porting "also" to the sub to augment the natural deep bass of the Magnepans.  I'm just wondering since there's precious little info in the 15hz to 25hz range, do I really need a PAIR of RELs, or could I get by with just one?  And shouldn't that one be capable of going REALLY low, like the G1, or what's the point?  Any advice would be appreciated.  Thanks.


Thank You for the update. I am interested in the new Aesthetix Mimas Integrated amp and would not mind an audition to compare against the Ayre.  Good to read that those Maggies are settling into your room/system nicely. 

Happy Listening!

@pwhinson, if cost is no object, and your 20.7’s give you enough output in the bottom octave (20-40Hz), look into the Eminent Technology TRW-17 Rotary Woofer. IAR’s Peter Moncrieff has characterized the TRW-17 as the world’s only true "subwoofer", as it is designed to reproduce only 20Hz DOWN! It provides substantial output all the way down to 1Hz, possible because it is not a woofer (whether cone, planar, horn, or any other traditional driver) pushing air, but a rotary fan. It’s a fascinating design (and it’s creator Bruce Thigpen a very clever and creative fellow), so head over to the ET website to read all about it.
I'm a newbie Maggie 20.7 owner as I just received a pre-owned pair in excellent condition. The SQ and feeling that the artists are in the room with you is unbelievable.  I would like to trial the use of a sub to allow the sub to handle frequencies at about 50Hz and below.  With all the positive remarks about Rel subs, is there a way to connect the Rel so that it limits the frequencies to the Maggies to 50Hz and above or is a crossover needed for this? 

I apologize if this is a common question answered in several places.