The "G" version (paper cone woofer, courtesy of GR Research’s Danny Richie) of the Rythmik F12---man, you are hip! Excellent sub for music. The paper cone is slightly lower in moving mass than the aluminum cone (good for music), the aluminum a little stiffer (good for high excursion movie sound effects). Danny feels the paper cone woofer provides a little more resolution than the aluminum, and a more natural sound quality. All I know is the woofer reproduces the sound of a well-recorded upright bass like no other I’ve heard. As the player descends down the neck of his bass, I hear no change in the timing of the playing, or in the timbre and transparency of my Quad ESL’s & Eminent Technology Magnetic-Planars. The lowest note on a standard 4-string bass (the open E string) is at 42Hz, and has a lot of overtones. The (acoustic) upright bass is an excellent test of the capabilities of a sub and the woofer of a speaker, highly revealing of any coloration or excess weight/fat, and driver "overshoot" and slow "settling" time---returning to rest after excursion (which causes smearing---a lack of transparency and resolution of fine detail). Rythmik Subs are characterized as "stopping on a dime".
The Rythmik sub features Brian Ding’s patented "Direct" (no accelerometer) Servo-Feedback circuit, the Vandersteen Richard’s unique feed-forward circuit, both good approaches to creating higher performance and lower distortion. Two of the best music subs available, either will satisfy. I myself have four of the paper cone G woofers, but in a version optimized for Open Baffle applications, installed in pairs in OB/Dipole H-frames. The only subs I’ve ever heard good enough for use with planar speakers---ESL’s, magnetic-planars, and ribbons.
