Package Includes: (2) Rockville Destroyer 15D1 15" Competition Car Audio Subwoofers w/USA Voice Coils! Video of DESTROYER SUBS: Features: Rockville DESTROYER 15D1 15" Dual 1-Ohm Car Subwoofer Peak Power Handling: 8000 Watts Program Power Handling: 4000 Watts CEA Rated RMS Power Handling: 2000 Watts Voice Coils are made in the USA! 3” 4-Layer Black Aluminum Voice Coils Wound with Aluminum Wire USA Voice Coils are hands down The Best in the world The voice coils are rated to withstand high temperatures of 300-350C, Triple-Stacked 300 Oz Y35 Magnets. (Y35 is the best grade and they will perform better than most 400 oz magnets) 1-Piece Chrome T-Yoke with Stamped Logo (1 piece t-yokes magnetize better and makes excursion (xmax) better as well as increases the BL rating. BL is basically how much power you get out of the motor and is one of the most important ratings We use the highest grade black glue that handles extremely high temperatures which allows our woofer to handle even more power than they are rated Cast Aluminum Basket With Black Sanded Finish Makes This Sub Very Efficient And Lighter Weight Large 8 Gauge Chrome-Plated Binding Post Terminals (These are the best terminals on the market and they won't oxidize) Black Non-Pressed Paper Cone Our cones are ultra-stiff. They are thicker and stronger than other subs on the market making our subs able to handle more power than the competition Extra Thick Foam Surround Provides Incredible Sound Quality With Minimal Distortion Silver Stitching Cone Reinforces the Cone and Ensures Long Life Shiny Paper Dustcap (Paper is the best material and can withstand even higher temperatures than polypropylene dustcaps Impedance: Dual 1-Ohm Voice Coils Special Custom Rubber Boot Magnet Covers Make the Woofer Look Nice and Protects the Magnet Rubber Mounting Gasket Makes it Easy To Mount the Subwoofer Air-Tight High BL Magnetic Motor Gap Nomex Spider is resistant to tearing and has the best long-term reliability over regular cotton and poly cotton spiders Cutout Diameter: 14.76” inches Mounting Depth: 9.76” inches Frequency Response: 33 Hz -1.5 K kHz 25mm T-Yoke + 15mm Washer Recone kits available at reasonable prices Sensitivity: 88.4 dB Sealed Enclosure Volume: 2.02-2.47 Cubic FeetVented/Ported Enclosure Volume: 3.16 - 4.41 Cubic Feet Weight: 52.92 Lbs. Shipping Weight: 56.23 Lbs. Shipping Box Dimensions: 18.9" x 18.9" x 15.35" Inches XMAX: 35 MM TS Parameters: Parameter Wired in Series Description of Measurement Electrical Parameters Re 1.7 Ohm Electrical voice coil resistance at DC Fo 35.896 Hz Drive resonance frequency Mechanical Parameters (Using Laser) Mms 318.205 g Mechanical mass of drive diaphragm assembly including air load and voice coil Mmd (Sd) 305.695g Mechanical mass of voice coil and diaphragm without air load Cms 61.781 mm/N Mechanical compliance of drive suspension Bl 14.898 N/A Force factor (Bl product) Loss Factors Qms 3.916 Mechanical Q-factor of of drive in free air considering Rms only Qes 0.550 Electrical Q-factor of drive in free air considering Re only Qts 0.482 Total Q-factor considering Re and Rms only Other Parameters Vas 53.280 Equivalent air volume of suspension n0 0.433% Reference efficiency (2 pi-radiation using Re) Sd 77.931cm² Diaphragm area SPL 88.4dB sensitivity Detailed Info: Body: Non-Pressed Paper Cone Gap Plate Inside Diameter: 85.5mm (3.37 inches) Gap Plate Outside Diameter: 210mm (8.27 inches) Gap Plate Thickness: 15mm (0.59 inch) Yoke Outside Diameter:210mm (8.27 inches) Yoke Thickness: 25mm (0.98 inches) Yoke Pole Diameter: 73.9mm (2.91 inches)