The FBT HiMaxX100SA powered subwoofer features a 0.7-inch birch plywood cabinet with scratch & scuff resistant black paint finish. The FBT HiMaxX 100SA features a custom designed B&C 18-inch woofer with a 3-inch voice coil, neodymium magnet structure and an aluminium die cast frame. The special band pass acoustic loading increases efficiency and maximum SPL. With frequency range of 38Hz to 120Hz, the HiMaxX 100SA providing floor shaking low frequency extension with a SPL of 139dB. The HiMaxX 100SA powered subwoofer features a 1200WRMS PWM (Pulse Width Modulation) passively cooled (no fan) low frequency amp that offers 90% efficiency.