General Specifications Nominal diameter 381mm / 15in Power rating 700watt-1500watt Nominal impedance 8 Sensitivity 96dB Frequency range 35-3500HZ Chassis type Cast aluminum Magnets type Ferrite Magnet size 220x110x20mm Magnet weight 2.8kg / 98.5oz Voice coil diameter 99.5mm / 4in Coil material CCA -W Number of layers 2 (Outside) Former material Glass Fiber Cone Material Paper Surround material Spider Single X-max 7mm / 0.27in Gap depth of 10 mm / 0.39in Voice coil winding width 22 mm / 0.86in