elf, if and when you want to spend more to get more, keep in mind that above a certain level, room integration will have more of an effect than the sub(s) it(them)selves. If you go to the Rythmik section in the AVS Forum, there are quite a few comments by Magneplanar speaker owners telling others about the pairing of Rythmik subs and those speakers. The F12 is a common choice with Maggies, F15 for bigger rooms. But the really interesting discussions take place on the GR Research Audio Circle Forum, in the threads relating to the unique OB/Dipole Sub created in a collaboration between Brian Ding of Rythmik and Danny Richie of GR Research. Any questions regarding the OB sub should be directed toward Danny rather than Brian.
A pair of the OB/Dipole Sub kits (each kit consists of two 12" woofers made expressly for OB use, and a plate amp with which to drive them. The amp also contains the Rythmik servo-feedback circuitry that controls the woofers, and an OB cancellation-compensating shelving circuit.) runs about $1500, and a pair of flat-pack H-frames in which to install the woofers and plate amp around $500. Assembling the H-frames is not much harder than an Ikea dresser, after you have painted or veneered (or have it done for you, as did Audiogon member kennythekey---see his Virtual System to see pics of the subs) them. THE sub for planars, as well as other high-performance loudspeakers.
