Nominal Diameter: 380/15 mm/inch Rated Impedance: 8 ohm Max Power: 1800 watts RMS Power: 900 watts Sensitivity: 97 dB Frequency Range: 36-1500 Hz Effective Piston Diameter: 340/13.4 mm/inch Minimum Impedance: 5 ohm Voice Coil Diameter: 99.2/4 mm/inch Voice Coil Material: Copper Voice Coil Winding Depth: 25/1.0 mm/inch Number of layers: 2 Kind of layer: outside Top Plate Thickness: 15/0.55 mm/inch Cone Material: no pressed pulp Cone Design: straight Surround Material: polycotton Surround Design: triple roll