Dual ferrite magnet motor assembly weighing nearly 40lbs generates immense magnetic force and excursion of the 13.5 -inch driver to produce massive low frequency output well below the limits of human hearing. | Edge wound voice coil with eight-layer aluminum flat wire minimizes distortion and power compression while providing excellent heat dissipation and linearity ensuring precise control. | Lightweight and rigid composite cone with premium glass fiber dustcap generate massive output with pinpoint accurate frequency response. | Proprietary injection molded gasket and long-throw parabolic surround ensure longevity and allow extreme excursion and SPLs.