The Eminence Lab 12 Is A 12-" Subwoofer Speaker That Handles 400 Watts Rms. Features A Die Cast Aluminum Basket For Strength. Double Stacked 80 Oz. Ferrite Magnets. In A Horn Loaded Cabinet The Lab12 Can Produce Bass Output Comparable To 6 To 8 Conventional 18-" Woofers. Nominal Basket Diameter: 12-"/304.8mm. Impedance: 4 or 6 ohms. RMS Power Rating: 400 Watts. Program Power Rating: 800 Watts. Sensitivity (1W/1m): 89.2dB SPL. Voice Coil Diameter: 2.5-"/63.5mm. Rec. Enclosure Vol. (Sealed): 22.7-28.3 Liters/0.8-1 cu. ft. Rec. Enclosure Vol. (Vented): 45.3-101.9 Liters/1.6-3.6 cu. ft. Mounting Information:. Overall Diameter: 12.32-"/312.8mm. Bolt Circle Diameter: 11.77-"/298.9mm. Baffle Cutout Diameter: 10.89-"/278.9mm. No. Of Mounting Holes: 8. Mounting Hole Diameter: 0.26-"/6.6mm. Thiele-Small Parameters. Resonant Frequency (fs): 22 Hz. Impedance (Re): 4.29 ohms. Coil Inductance (Le): 1.48mH. Electromagnetic Q (Qes):.39. Mechanical Q (Qms): 13.32. Total Q (Qts):.38. Compliance Equivalent Vol. (Vas): 125.22 Liters/4.42cu. ft. Voice Coil Overhang (Xmax): 13.0mm. BL Factor (BL): 15.0T-M. Surface Area of Cone (Sd):.05067m2.