Lightweight yet powerful active subwoofer units with inbuilt class D amplifiers. Each cabinet is constructed from 15mm MDF with integral side handles for easy portability and 35mm socket to accommodate a mounting pole. The high flex sub driver is front-loaded with a protective steel grille to deliver powerful transients and add warmth to any sound system. The class D amplifier section has stereo line inputs and outputs to allow use either as a mono sub with stereo tops or a matching sub for each top speaker. Line inputs have a parallel Link output to pass the signal onto further active speakers and a pair of line outputs with switchable high pass filter to connect to active top cabinets. A phase switch is included to help avoid sound cancellation and time-align multiple speaker setups. Designed as a perfect match for the CASA series speakers and equally at home with other active full range cabinets.