Do audiophiles hate large subwoofers?

@ivan_nosnibor, the amplifiers in the Rythmik plate amps are not bandwidth limited, they are "normal" Class A/B (the A370 model) or H (the H600 model) full range amplifiers. It is the filter settings chosen by the user that determines at what frequency roll off occurs. All Rythmik plate amps provide controls related to low-pass filtering (the frequency at which the sub's output is rolling off at the upper end of it's operating range), and even a filter for rolling off the low end of the sub (at either 14, 20, or 28Hz), along with a "damping" control, with high, low, and medium settings. One model plate amp (the A370PEQ) also provides high-pass filtered outputs on a pair of RCA jacks (that output signal is sent to the amp powering the main speakers used with the sub). That high-pass filtering is achieved via opamps (as it is in most crossovers), which are in general not "audiophile approved" ;-) . 

Ivan, while the controls on the Rythmik Audio plate amps (Danny sells the Rythmik A370 amp for use with his paper-cone version of the Rythmik 12" aluminum-cone woofer, but the amp was designed and is built by Brian Ding of Rythmik) indicate that low pass filtering is possible up to "only" 120Hz, the amp is also available in a special version which has been modified by Ding for use in the OB/Dipole sub; that is the version of the amp which provides output up to 300Hz. Kind of confusing!

Ivan, there is one sub that is usable up to 300Hz---the Rythmik Audio/GR Research OB/Dipole. You can check it out on the GR and Rythmik websites (though a result of the collaboration between GR’s Danny Richie and Rythmik’s Brian Ding, the sub is more Danny’s than Brian’s baby), as well as the GR AudioCircle Forum. A pair of 12" paper cone woofers mounted in an H-frame, with servo-feedback and dipole-cancellation compensation shelving circuits in the integral plate amp. A very unique sub, the only one of it’s kind!

The Rythmik A370 and H600 plate amps (found in the F12, F15, F18, and F25 models) are available in versions (the PEQ, not the XLR) that provide both line level (on RCA jacks) and high level (on binding posts) inputs. REL subs of course have a great rep with audiophiles, as do Rythmiks.