The FBT Verve 18sa Powered Speaker features a 13 ply birch plywood cabinet with Scratch & Scuff resistant black paint nish. The FBT Verve 18sa features a custom designed B&C® 18” woofer with a 3" voice coil, a neodymium magnet structure and an aluminum die cast frame. The active internal stereo crossover is at a xed frequency of 100Hz. The Verve 18sa offers a frequency range of 33Hz -100Hz, providing oor shaking low frequency extension with a SPL of 126.5 dB. The Verve 18sa powered subwoofer features a 600w RMS Class D, Digital PWM (Pulse Width Modulation) passively cooled (no fan) low frequency amp, that offers 90% efciency. The FBT Verve 18sa amplier design, prevents annoying Thermal shutdowns that plague many other powered speakers and powered subwoofers.