Polk Audio PSW110 10-Inch Powered Subwoofer (Single, Black) Floor Coupled Downward Firing Port Dynamic Balance Composite Woofer Clipped Optimized Woofer A single 10-inch subwoofer with compression circuitry to limit distortion at earth-shaking volume levels Equipped with one 10-inch dynamic balance composite woofer driver Features laser-based Klippel measurement technology for improved linearity and deep, precise sound Frequency Response: 35Hz - 250Hz Peak power handling: 150 watts (60 watts continuous)