Sundown Audio X-8 V.2 D2 8" Dual 2-Ohm XV2 Series Car Subwoofer Sundown Audio 8" Dual 4-ohm XV2 Series Car Subwoofer | Power Handling: RMS: 750 watts Solid Pole piece with machined air channels for increased voice coil cooling | High velocity under-spider frame vents | Black Aluminum 2.5" voice coil former for superior heat dissipation High Temperature copper voice coil wire | Large aluminum shorting (faraday) ring | Spring Loaded Terminals Stitched-On Double High-Power Tinsel Lead Wires | High strength and patented cast aluminum frame | Optimized for small ported enclosures X max = 19mm one-way by 70% BL | Ported Enclosure Size Recommendations: .75-1.0 ft^3 | Mounting Depth: 7.00" | Outside Diameter: 8.70" Cut-Out: 7.36" | Recommended Tuning: 32hz | Recommended Port Area: 12-16 in^2