PYLE-PRO PDW21250 - 21'' Performance Optimized  High Power Subwoofer 21'' High Power Subwoofer - 1000 Watts RMS / 2000 Watts Peak Power Handling 22Hz Resonance - Frequency Response: 22Hz ~ 4kHz - Sensitivity (1W/1M): 107dB Magnet Weight: 350oz. - 4'' Aluminum Voice Coil Diameter: 21.8'' - Mounting Depth: 10.2'' Die-Cast Aluminum Frame - 8 Ohm Impedance