Pioneer TS-A30S4 12" 1400W (400W RMS) Single 4 ohm Voice Coil Car Subwoofer Features: Size 12" Continuous Power Handling (RMS) 400W Maximum Peak Power Handling 1400W Impedance 4Ω Woofer Composition Glass fiber and mica reinforced Injection Molded Polypropylene (IMPP) Woofer Surround Butyl Rubber Woofer Magnet Composition Ferrite Magnet Weight Mounting Depth 136mm Sensitivity (1W/1 m) 87dB Frequency Range 22 Hz to 1.6 kHz