The Q Power GMC12DF is a custom-fit dual 12-inch down-firing subwoofer enclosure designed specifically for 1999–2006 Chevrolet Silverado and GMC Sierra Extended Cab trucks. Engineered for powerful low-frequency performance while maintaining valuable interior space, this enclosure mounts neatly under the rear seat and features a down-firing design that helps protect subwoofers from cargo damage and daily wear. Built from durable MDF wood and wrapped in premium charcoal automotive carpet, the GMC12DF delivers deep, clean bass with an OEM-style appearance that blends seamlessly into the truck interior. Features & Highlights Custom-fit dual 12-inch subwoofer enclosure Designed for 1999–2006 Chevy Silverado & GMC Sierra Extended Cab trucks Under-seat down-firing enclosure design Protects subwoofers from cargo and impact damage Durable MDF wood construction Premium charcoal automotive carpet finish Space-saving OEM-style fitment Designed for strong low-frequency bass response Compatible with most shallow and standard-mount 12-inch subwoofers Extended Cab only — does NOT fit Crew Cab models Ideal for daily-driver and aftermarket truck audio systems Specifications Specification Details Enclosure Type Dual 12" Sealed Down-Firing Vehicle Fitment 1999–2006 Chevy Silverado / GMC Sierra Extended Cab Subwoofer Size Dual 12-Inch Configuration Under-Seat Down-Fire Material MDF Wood Construction Finish Premium Charcoal Carpet Air Space 0.95 cu. ft. per subwoofer Mounting Depth 5.5" Width 55" Height 12.75" Depth 3.5" Top / 11" Bottom Compatibility Extended Cab Only Crew Cab Compatible No Application Truck Audio Systems
