200W Rms 4 Ohm Rubber Surround Woofer Poly Cone 15 Inch General Specifications: Nominal Diameter: 15 inch. Rated Impedance: 4Ohms. Operating Bandwidth: 50 to 3KHz (-3dB). Power Handling Capacity: 200W RMS. Sensitivity (1W/M): 92dB (3dB). Voice Coil Diameter: 2 inch. Thiele-Small Parameters: Resonance Frequency Fs: 32.5Hz. DC Resistance Re: 3.4O. Mechanical Q Factor Qms: 3.203. Electrical Q Factor Qes: 0.5342. Total Q Factor Qts: 0.4578. Equivalent Cas air load Vas: 322.23 L.