Help with sub upgrade


I am looking at upgrading my subs in my HT system. Paradigm Sig4's and C3 up front, Anthem AVM30, Denon 3910 and Mac 207 amp. The room is 13w x 26l and 7.5h, Seating position is 12ft from front. Currentlty i am considering 2 JL F112's vs 2 ML's depths or perhaps a three sub REL system (B2, r305 i have one, and a T1 in the back. The system is 90% movies but i care a lot about how music sounds. I have space issues so the subs i have listed all fit where they need to go. Thanks for any thoughts that you might share. P.S. i would have gone with paradigm subs but they are too deep for the alloted space.
docrobbi
+1 for the Rythmik sub suggestion. The intergration between the servo driver and plate amp make it a very strong contender at a reasonable price. I own one and it replaced a Vandy sub.
I have read a bit about the Rythmik subs but am unclear how low they will go for HT? Two of the rythmiks and and a sub eq together would be a lot less than a single JL. I have looked at the svs as well but their box subs are too deep. I need a sub around 20 in deep to fit in my cabinetry. The cylinder subs don't do it for me.
Docrobbi,

A pair of 12" Rythmiks will produce (near) state of the art performance data down to app 35hz @ 100db - anechoic. In my room, I get flat response to 30hz w/no EQ and 25hz with app 4db boost below 30hz. I filter to eliminate response below 25hz, because it's a music only system and I have (virtually) no music w/info below 25hz.

I can't measure THD, but I certainly don't hear any and there is very little travel from the drivers at my max listening levels so I imagine it's pretty low. In short, I believe that there's plenty of room for more clean output and/or deep bass extension in my set-up, I just don't have the program material/spl needs to ever access it. Your room, listening levels, program material etc may well differ, so YMMV.

Marty

PS HT.shack has the Rythmik test results under DIY subs. The model that they tested was evidently a kit that, according to Brian @ Rythmik, was a WIP predecesor whose performance was similar to, though not quite as good as, the current model.
I vote for the jl audio --but would buy 1 f113 see how you like it --save a few bucks and then buy a second one and don't look back as they are great subs.
I have to agree with the JL Audio subs but instead of 1 F113 like the previous posts suggest just go for the pair of F112's.

If you have any woodworking skills then you can get comparable performance and save some big $$$ in the process. My DIY subs lack some definition and clarity compared to the Fathom F113 I previously had but for movies they blow it out of the water. I have never heard a more articulate sub then the Fathom F113 I owned for music though and that includes most of the top brands.