WA118SA USES 18 "imported neodymium magnetic bass unit (4" voice coil);Built-in 2 channel active power amplifier module (1500w/8Ω×1;600w/8Ω×2), with DSP (1 in 3 out) digital audio processing function, built-in presets can be preserve or load; It is a universal active ultra-low frequency speaker, which can be flexibly combined with any full-frequency speaker, and is convenient and fast to install. It is designed to provide high definition solutions for fixed installation and small mobile sound amplification system.