Take a look at the JTR Captivator. I commissioned that design to keep up with our very high output main speakers. The Epik is a heck of a sub...does 104 db at 16 hz which is pretty exceptional for a small sub.
The Captivator was designed by Mark Seaton. It does 112 db at 16 hz. Both are roughly the same price, Captivator comes in a bit higher since it is passive. Captivator is fairly large at 40" x 31" x 24"...but to fit that much gear, your room must be huge.
Yes I am JTR's Home Theater dealer...add grains of NaCl as appropriate.
Authorized Dealer for Klipsch, Klipsch THX Ultra2, Klipsch Heritage, Klipsch Reference, JTR LoudSpeakers, Face Audio, Bryston, Earthquake, Velodyne, Danley Sound Labs, Crown, , a really kick ass infrasound sub, ...and a lot of other good stuff.
Remember...two out of the four letters in the word
Bose are BS.