Alpine R2-W12D4 12" R-Series "R2" Subwoofer, Dual 4-Ohm, 750 Watt RMS PRODUCT OVERVIEW 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. 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. General Specs: • Size: 12” • Dimensions: 11.61” x 11.61” x 6.43” • Frequency Response: 24Hz - 200Hz • Power Range: 300W - 750W RMS • Power Handling: 750W RMS / 2250W Peak • Magnet Weight: 144 oz • Voice Coil Diameter: 65.5 mm (2.6”) T/S Parameters: • Sensitivity (1W/1m): 84.6 dB • DC Resistance (Re): 3.5Δ + 3.5Δ • Free Air Resonance (Fs): 30 Hz • Equivalent Stiffness: 32.8 L • Mechanical Q (Qms): 6.51 • Electrical Q (Qes): 0.55 • Total Q (Qts): 0.51 • Cone Area (Sd): 479 cm2 • Linear Excursion (Xmax): 20 mm • Mechanical Travel (Xmech): 72 mm BOX SPECS - SEALED BOX RANGE: Net Internal Volume: 0.55 - 1.0 ft3 RECOMMENDED SEALED BOX: External Dimensions: 14” x 14” x 11” Gross Internal Volume: 0.85 ft3 Net Internal Volume: 0.75 ft3 VENTED BOX RANGE: Net Internal Volume: 1.0 - 1.5 ft3 Fb, Tuning: 33-37 Hz RECOMMENDED VENTED BOX: External Dimensions: 12.5” x 14” x 25.5” Gross Internal Volume: 1.91 ft3 Vent Area (W x H): 18.75 in2 (12.5” x 1.5”) Vent Length: 22” Vent Displacement: 0.36 ft3 Net Internal Volume (Vb): 1.45 ft3