Two Alpine R2-W12D4 12″ R-Series “R2” Subwoofer, Dual 4-Ohm, 750 Watt RMS Features – 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