Subwoofer - thoughts on Rythmic F12

No @dabel, I’m just saying I hadn’t heard a word about a problem between TC Sounds and Rythmik. In fact, your mention of it is news to me. That doesn’t mean it’s not true, of course.

But it does make me glad I got my woofers (four of the paper-cone 12’s optimized for open baffle use, two of the Rythmik aluminum-cone 15’s) when I did. I put the 12’s in a pair of open baffle W-frames built to Danny’s specs (viewable on the GR Research website), the 15’s in 4cu.ft. sealed enclosures of my own design (double-walled using 3/4" MDF, triple-layer baffle). I copied Jim Salk’s bracing (he builds his subs using the Rythmik kits, both 12" and 15"), the best I’ve ever seen. I put in braces every 6", front-to-back, side-to-side, and top-to-bottom.

I find most hi-fi’s woefully lacking in the ability to make music visceral (too much head, not enough body). Good subs help a lot.

@dabel: I hadn’t heard about recent problems at TC Sounds, though I seem to remember hearing something awhile back about their amazing LMS Ultra 15" (or was it an 18"?) woofer being no longer available. That woofer was for years considered state-of-the-art for DIY home theater sub builders. I’m sure a call or email to Brian Ding at Rythmik would bring an answer. Warning: Mr. Ding is rather hard to understand, his accent pretty pronounced (no pun intended ;-) .

@gladmo makes a great point about the lower moving mass of the paper cone version of the F12, and the resulting reproduction of low frequency fine detail.

I have a pair of the Rythmik Audio/GR Research OB/Dipole Subs, each of which employs a pair of the paper cone woofer that has been optimized for open baffle use. Imagine the "speed" (settling time) of the F12 servo-feedback woofer, with no enclosure! It's the only woofer/sub I've ever heard that blends well with dipole planar loudspeakers (including a pair of KEF B139 woofers in transmissionline enclosures I own). If you've heard the Magnepan bass panels of the big Tympani and MG30.7 models you have an idea of the sound of the OB/Dipole Sub, but with reproduction of even the bottom octave (20-40Hz). But an OB/Dipole sub is not for everyone, or every application. For those there is the Rythmik Audio F12. I have no doubt a lot of REL and JL Audio owners would be very surprised if they ever heard a Rythmik sub.

One thing to be aware of is that the F12 is available with your choice of an aluminum coned-woofer (the F12), and with a paper coned one (the F12G, the "G" to signify GR Research, whose Danny Richie collaborates with Rythmik Audio’s Brian Ding).

Choosing between the aluminum and paper cone may be dependent upon whether you want to prioritize music, or movies. Rythmik Audio’s Brian Ding prefers aluminum cones for their greater stiffness (compared with paper)---less cone "flexing", Danny Richie the paper cone for it’s more "natural" (he feels) sound when reproducing music, especially that played on acoustic instruments.

Either one will be a worthwhile upgrade from the SVS SB-12.