This next evolution subwoofer uses a new, longer, four layer aluminum voice coil. The result is more energy in the gap, less heat, higher sensitivity, higher power handling, lower distortion and better overall performance. Features a 40mm long, 4.5 inch diameter (116mm) Copper Clad Aluminum Wire voice coil. With a 1700watt AES power rating, 98 dB sensitivity, and over 14.0mm of Xvar, this high energy subwoofer is a significant step forward from similar models in the B And C range. * 18.0 inches Diameter. * Continuous power handling: 3400 W. * Voice coil diameter: 4.5 in (116 mm). * Magnet material: Neodymium Inside Slug. * Nominal Diameter: 460 mm (18.0 in). * Nominal Impedance: 8 Oms. * Minimum Impedance: 7.0 Ohms. * Nominal Power Handling: 1700 W. * Continuous power handling: 3400 W. * Sensitivity (1W/1m): 98.0 dB. * Frequency Range: 30 - 500 Hz. * Voice Coil Diameter: 116 mm (4.5 in). * Winding Material: Aluminium. * Former Material: Glass Fibre. * Winding Depth: 40.0 mm (1.57 in). * Magnetic Gap Depth: 14.0 mm (0.55 in). * Flux Density: 0.8 TDesign. * Surround Shape: Triple Roll. * Cone Shape: Radial. * Magnet Material: Neodymium Inside Slug. * Spider: Double Silicone. * Pole Design: T-Pole. * Woofer Cone Treatment: TWP Waterproof Both Sides. * Recommended Enclosure: 100.0 dm3 (3.53 ft3). * Recommended Tuning: 40 HzParameters4. * Resonance Frequency: 30 Hz. * Overall Diameter: 460 mm (18.11 in). * Bolt Circle Diameter: 442 mm (17.4 in). * Baffle Cutout Diameter: 422.0 mm (16.61 in). * Depth: 248 mm (9.76 in). * Flange and Gasket Thickness: 16 mm (0.63 in). * Air Volume Occupied by Driver: 10.0 dm3 (0.35 ft3). * Net Weight: 12.0 kg (26.46 lb). * Shipping Units: 1. * Shipping Weight: 13.6 kg (29.98 lb). * Shipping Box: 500x495x275 mm (19.69x19.49x10.83 in)Service Kit. * Recone kit: RCK18DS1158