Description Package Includes: (2) Alpine R2-W8D2 8” R-Series 350W RMS Subwoofer Dual 2 Ohm Car Audio Sub R2W8D2 (1) Rockville RQB8 Dual 8″ Vented Subwoofer Sub Box Enclosure Finished w/Bed Liner (1) Dual Sub Box Enclosure Installation Kit: Speaker Wire, Screws, Spade Terminals Description of R2-W8D2: The next generation of sound performance is here with the new R-Series subwoofers featuring a larger motor structure for more accurate and authoritative bass. Features of R2-W8D2: New Motor Structure The new R-Series subwoofers now feature larger, double-stacked magnets that contribute more motor force for deeper bass and tighter bass control compared to the previous generation. Oversized Dust Cap The new hybrid poly ceramic composite dust cap ensures rigidity while also providing incredible internal damping (vibration absorption) to smooth out the bass response and reproduce tight bass. Increased Accuracy Alpine’s High Amplitude Multi-Roll (HAMR) Surround Technology allows the cone to efficiently move air while staying cool resulting in incredible accuracy from the subwoofer. Specifications: Size: 8″ Dimensions: 7.64″ x 7.64″ x 4.56″ Frequency Response: 30Hz – 200Hz Power Range: 150W – 350W RMS Power Handling: 350W RMS / 1000W Peak Magnet Weight: 56 oz Voice Coil Diameter: 40 mm (2.6″) THIELE-SMALL PARAMETERS Sensitivity (1W/1m): 83.6 dB DC Resistance (Re): 1.8? 1.8? Free Air Resonance (Fs): 42 Hz Equivalent Stiffness: 10.1 L Mechanical Q (Qms): 7.69 Electrical Q (Qes): 0.52 Total Q (Qts): 0.48 Cone Area (Sd): 201 cm2 Linear Excursion (Xmax): 12 mm Mechanical Travel (Xmech): 52 mm SEALED BOX RANGE Net Internal Volume: 0.15 – 0.45 ft3 RECOMMENDED SEALED BOX External Dimensions: 13″ x 13″ x 5.5″ Gross Internal Volume: 0.30 ft3 Net Internal Volume: 0.25 ft3 D2 – F3, Qtc: 59Hz, 0.73 D4 – F3, Qtc: 59Hz, 0.72 VENTED BOX RANGE Net Internal Volume: 0.25 – 0.7 ft3 Fb, Tuning: 36-40Hz RECOMMENDED VENTED BOX External Dimensions: 11″ x 9.5″ x 21″ Gross Internal Volume: 0.86 ft3 Vent Area (W x H): 8 in2 (8″ x 1″) Vent Length: 17.5″ Vent Displacement: 0.13 ft3 Net Internal Volume (Vb): 0.68 ft3 Features of RQB8: Finished with Durable Bed Liner 3/4″ MDF High Qua Brand: ALPINE Manufacturer Part Number: (2) R2-W8D2 RQB8 K2 Manufacturer: Alpine