Danny (and anyone else!)---I posted an expanded version of this question on the Rythmik site and received no responses, but one guy suggested I ask it here. Having already decided to get myself a pair of Rythmik subs for use in my music-only hi-fi system in a sealed 10(H)' X 13' X 19' room, and crossed over to my old Quad ESL's at 80-100hz, what are the differences in sound between the GR driver and the Rythmik when used in an F12? I do like to crank AC/DC every so often, but I listen mostly to Baroque and Bluegrass (in other words, acoustic instruments and vocals) at room-filling volume. I'm looking for subs that provide the same transparency, immediacy, and open quality as the Quads, and while I'm sure both drivers will give me that, how do they differ? Anybody heard both versions?