Nominal Diameter: 380/15 mm/inch Rated Impedance: 8 ohm Max Power: 1000 watts RMS Power: 500 watts Sensitivity: 99 dB Frequency Range: 40-2000 Hz Effective Piston Diameter: 330/13 mm/inch Minimum Impedance: 5 ohm Voice Coil Diameter: 75.5/3 mm/inch Voice Coil Material: Copper Voice Coil Winding Depth: 20/0.8 mm/inch Number of layers: 2 Kind of layer: outside Top Plate Thickness: 14/0.4 mm/inch Cone Material: no pressed pulp Cone Design: curved Surround Material: polycotton Surround Design: M-roll