Product Details: 15" Dual 2-ohm X Series SPL Subwoofer Power Handling: Peak: 4000 watts RMS: 2000 watts Designed for Extremely Low Bass 30 mm Xmax (One Way) Enhanced Woven Fiber Paper Composite Cone Custom High-Roll Foam Surround with Black Nylon Stitching Precision-Engineered Custom Tooled Die-Cast Aluminum Basket with Reinforced X Bracing for Structural Strength Vent Cooling Spacer to Maintain Optimal Airflow and Keep the Voice Coil Cool 3.0" High Temperature Flat Wire CCAW Aluminum Voice coil with Black Aluminum Former 4-Layer Linear Roll Spider with Integrated Tinsel Leads for Enhanced Linearity and Durability Optimized High-Velocity Pole Vent One-piece T-yoke with Vented Magnet Gap for Efficient Heat Dissipation 409 oz. Triple Stacked Ferrite Magnet with Protective Rubber Boot Heavy-Duty 4-Gauge Hex Key Speaker Terminals Frequency Response: 20 - 200 Hz Resonance Frequency (Fs): 34.0 Hz Sensitivity: 87.3 dB Recommended ported box volume: 4.25 cubic feet Top-mount depth: 11.41" Cutout diameter: 13.81" CTA-2031 Compliant 1-year Warranty from the Original Purchase Date T/S Parameters: Fs: 35.7 Hz QES: 0.608 QMS: 3.500 QTS: 0.518 Vas: 42.24 L Xmax: 30 mm SPL (1W/1M): 85 dB Sd: 754 cm² Re: 1.8 Ω + 1.8 Ω BL: 16.72 MMS (Grams): 433.70 Cms (uM/N): 97.40 Displacement: 0.22 cu ft Net Weight: 58.42 lbs XCW owner’s manual