21-in 4000 Watt High Power Low Distortion Neodymium Woofer 4 ohms

Nominal Diameter: 530 mm 21.0 in. Nominal Impedance: 4 Ohms. Minimum Impedance: 4.2 Ohms. Nominal Power Handling: 2000 W. Continuous power handling: 4000 W. Sensitivity 1W/1m: 96.0 dB. Frequency Range: 30 - 1000 Hz. Voice Coil Diameter: 153 mm 6.0 in. Winding Material: Copper. Former Material: Glass Fibre. Winding Depth: 30.0 mm 1.18 in. Magnetic Gap Depth: 12.0 mm 0.5 in. Flux Density: 1.2. 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: 190.0 dm3 6.71 ft3. Recommended Tuning: 33 HzParameters4. Resonance Frequency: 32 Hz. Overall Diameter: 547 mm 21.5 in. Bolt Circle Diameter: 527 mm 20.7 in. Baffle Cutout Diameter: 508.0 mm 20.0 in. Depth: 261 mm 10.3 in. Flange and Gasket Thickness: 16 mm 0.63 in. Air Volume Occupied by Driver: 16.0 dm3 0.56 ft3. Net Weight: 18.5 kg 40.7 lb. Shipping Units: 1. Shipping Weight: 20.8 kg 45.86 lb. Shipping Box: 570x570x320 mm 22.44x22.44x12.60 inService Kit. Recone kit: RCK21SW1524D