Like the SuperSub XXL, the ultra-compact SuperSub X (just a little bigger than a 12-1/2" cube) utilizes the same dual-plane, patented* inertially-balanced driver array, but instead employs two horizontally-opposed 8˝ ultra-long-throw active drivers and two vertically-opposed 10-1/2˝ x 9-1/2˝ planar infrasonic radiators, driven by a 1400 watt Class D Digital amplifier. "Simply unbelievable"raved the press about its stunning output after their first audition.