The LA12-B is NOT a subwoofer, it is a sensor controlled bass extension system operating in the range 28 - 200 Hz which overlaps both the low range of AIRLINE LA12 and the SC8 subwoofer providing essential more energy and control in the lower range of the system. Incorporating dual 15” drivers in a compact, vented enclosure it provides a distinctive 15” signature punch to the system. The LA12-B is equipped with two extremely long excursion 15” neodymium ultra low distortion drivers with integrated velocity sensor that measures, compares and controls cone movements. The neodymium motor delivers extreme high magnetic flux for increased efficiency. The 4” voice coil is 36 mm high, ensuring ultra linear excursion of 26 mm / pp at consistent magnetic force. State of the art carbon-fiber cones ensure maximum stiffness and low moving mass. Three aluminum shorting rings reduce inter-modulation distortion; minimize induction variation while reducing thermal compression. This design reduces dramatically the distortion of a typical subwoofer at longer excursion levels, and improves the overall sound quality and performance characteristics of the cabinet. The sensor is in fact an additional voice coil connected to the loudspeakers voice coil in a high precision, magnetically shielded system.