Watts 400W Music Program 800W Resonance 51Hz Usable Frequency Range 52Hz - 4.5kHz Sensitivity 99.2dB Magnet Weight 80 ounce Gap Height 0.37", 9.53mm Voice Coil Diameter 2.5", 63.5mm THIELE and SMALL PARAMETERS Resonant Frequency (FS) 51Hz DC Resistance (Re) 5.71 Coil Inductance (Le) 0.84mH Mechanical Q (QMS) 7.56 Electromagnetic Q (QES) 0.37 Total Q (QTS) 0.35 Compliance Equivalent Volume (Vas) 81.7 liters / 2.9 cu.ft. Peak Diaphragm Displacement Volume (VD) 242cc Mechanical Compliance of Suspension (CMS) 0.21mm/N BL Product (BL) 15.3 T-M Diaphragm Mass Inc. Air load (MMs) 48 grams Efficiency Bandwidth Product (EBP) 138 Maximum Linear Excursion (XMAX) 4.6mm Surface Area of Cone (SD) 532.4 cm2 Maximum Mechanical Limit (XLIM) 13.7mm MOUNTING INFORMATION Recommended Enclosure Volume Sealed 28-35 liters / 1-1.25 cu.ft. Vented 31-91 liters / 1.1-3.2 cu.ft. Driver Volume Displaced 155.5 cu.in. / 2.55 liters Overall Diameter 12.38", 314.5mm Baffle Hole Diameter 11.07", 281mm Front Sealing Gasket Fitted as standard Rear Sealing Gasket Fitted as standard Mounting Holes Diameter 0.27", 6.9mm Mounting Holes B.C.D. 11.57", 293.8mm Depth 6.22", 158mm Net Weight 16.3 lbs., 7.4 kg Shipping Weight 18 lbs., 8.2 kilos MATERIALS OF CONSTRUCTION Coil Construction Aluminum voice coil Former Polyimide former Magnet Composition Ferrite magnet Core Details Vented and extended core Basket Materials Die-cast aluminum basket Cone Composition Paper Cone Edge Composition Cloth cone edge Dust Cap Composition Solid composition paper dust cap