Sundown Audio Z-12 V.5 D1 12" 2000W RMS Dual 1-Ohm Z-V.5 Series Subwoofer Dual 1-Ohm 2000W RMS Z-V.5 Series Subwoofer Specifications: DC Resistance (Re): 2.0  | Resonance Frequency (Fs): 33 Hz | Equivalent Volume (Vas): 21.1 L | Electrical Q Factor (Qes): 0.52 | Mechanical Q Factor (Qms): 3.63 | Total Q Factor (Qts): 0.46 | Voice Coil Inductance (Le): 0.73 mH | Force Factor (BL): 15.2 NA | Moving Mass (incl. Air Load) (Mms): 291.5 g | Suspension Compliance (Cms): 0.08 mm/N | Sensitivity: 83.4 dB 1w / 1m Box Recommendations: Sealed Enclosure Suggestion: Not Recommended | Ported Enclosure Suggestion: 25 cu. ft. | Displacement: 0.23 cu. ft. | Depth: 11.27 in | Outside Diameter: 12.67 in | Cutout: 11.09 in | Recommended Tuning: 32 Hz | Recommended Port Area: 40 sq. in.