IDMAX10 V.4 D4 - Image Dynamics 10" Dual 4-Ohm IDMAX V.4 Series Subwoofer 10" Dual 4 ohm ID MAX V.4 Series Subwoofer | Pressed paper composite cone woofer | Parabolic EPDM rubber surround Over 2" long linear excursion | RaDiaToR cooling system for heat dissipation | Radiant Diametric Torisonal Reinforcement | High compliance suspension design | Flat spider with NOMEX cloth woven tinsel leads | High-temperature flat wire, flat wound voice coil | Inverted dust cap with logo | Powder coated alloy proprietary basket | 3-1/2" peak-to-peak surround excursion Power Handling: Peak: 1800 watts | RMS: 1000 watts | Recommended Power Range: 200-1000 watts Nominal Impedance (IMP): Dual 4  | DC Resistance (Re): 3.15  | Resonance Frequency (Fs): 26.87 Hz | Equivalent Volume (Vas): 48.35 L | Electrical Q Factor (Qes): 0.52 | Mechanical Q Factor (Qms): 2.91 | Total Q Factor (Qts): 0.44 | Peak Excursion (Xmax): 39 mm | Piston Area (Sd): 394.00 cm2 | RMS Power: 1000 W | Sensitivity: 84.50 dB 1w/1m Sealed Enclosure Suggestion: 0.75 cu.ft. | Ported Enclosure Suggestion: 1.5 cu.ft. | Displacement: 0.11 cu.ft. | Mounting Depth: 7.68 in | Outside Diameter: 11.06 in | Cutout: 9.65 in