Phase Tech Subs Are Wireless but No Longer Ambulatory

The Power WL subwoofers from Phase Technology can run wired or wireless using an uncompressed signal in the 2.4GHz band. They're available in eight-, ten-, or twelve-inch versions at prices from $900-1300, backed with a 900-watt amp, allowing linear peak-to-peak excursion of 2.5 inches. Why are the active drivers on the bottom and the passive radiators on the front? The designers found the subs were "walking themselves across the floor," and therefore swapped the drivers to keep them in one place.