Power Rating Watts 1250W Music Program 2500W Resonance 41Hz Usable Frequency Range 44Hz-800Hz Sensitivity 95.5 Magnet Weight 109 ounce Gap Height 0.375", 9.53mm Voice Coil Diameter 4", 101.6mm THIELE and SMALL PARAMETERS Resonant Frequency (FS) 41Hz DC Resistance (Re) 4.97 Coil Inductance (Le) 1.78mH Mechanical Q (QMS) 8.80 Electromagnetic Q (QES) 0.40 Total Q (QTS) 0.39 Compliance Equivalent Volume (Vas) 154.5 liters / 5.5 cu.ft. Peak Diaphragm Displacement Volume (VD) 677cc Mechanical Compliance of Suspension (CMS) 0.15mm/N BL Product (BL) 17.7 T-M Diaphragm Mass Inc. Air load (Mms) 98 grams Efficiency Bandwidth Product (EBP) 103 Maximum Linear Excursion (XMAX) 7.9mm Surface Area of Cone (SD) 856.3 cm2 Maximum Mechanical Limit (XLIM) 13.5mm MOUNTING INFORMATION Recommended Enclosure Sealed Vented 82-176 liters/2.9-6.2 cu.ft. Overall Diameter 15.21", 386.3mm Baffle Hole Diameter 14.0", 355.6mm Front Sealing Gasket fitted as standard Rear Sealing Gasket fitted as standard Mounting Holes Diameter 0.28", 7mm Mounting Holes B.C. D. 14.56", 369.8mm Depth 6.42", 163mm Net Weight 24.7 lbs., 11.2 kg Shipping Weight 27.1 lbs., 12.3 kg MATERIALS OF CONSTRUCTION Coil Construction Copper voice coil Former Polyimide former Magnet Composition Ferrite magnet Core Details Extended core with Core Periphery Ventilation Basket Materials Die-cast aluminum basket Cone Composition Paper Cone Edge Composition Cloth cone edge Dust cap Composition Porous cloth top spider/ heat sink