Phoenix Gold RSD10 Dual 10-Inch 4-Ohm Voice Coil Subwoofer Power Handling (RMS/Peak): 350W/700W Sensitivity: 91dB @ 2.83/1M Frequency Response: 25Hz - 200Hz Impedance: 4/4 Ohms Butyl Rubber Surround with Injection Molded Aluminum Plated Polypropylene Cone