Specifications. Brand:FAITAL PRO; Model:18HP1010; Nominal Diameter:18"; Nominal Impedance:4ohm; RMS Power:1000 W; Peak Power (Watts):2000 W; Sensitivity (dB):98 dB; Max Excursion(Xdam)(Xlim):21.9 mm; Max Linear Excursion (Xmax):9.75 mm; Usable Frequency Range (Hz):35-2k Hz; Surround Shape:Triple Roll; Basket / Frame Material:Aluminum; Spider Detail/Material:2x non-adjacent symmetrical constant height waves; Voice Coil Diameter:4"; Voice Coil Former:Glass Fiber; Voice Coil Wire Material:Copper; Voice Coil Winding Depth:23 mm ; Voice Coil Gap Height:10.5 mm ; Demodulating Ring:No; Magnet Material:Ferrite . Parameters. Compliance Equivalent Volume (Vas):7.16 Ft3; Total Q (Qts):0.31; Mechanical Q (Qms):7.8; Electromagnetic Q (Qes):0.32; Minimum Impedance (Zmin):3.5ohm; DC Resistance (Re):2.7 ohm; Mechanical Resistance (Rms):11.55 lbs/sec; Surface Area of Cone (Sd):175.77 in2; Voice Coil Inductance (Le):1.26 mH; Flux Density:1.05 T; BL Product(Bl):18.4 T-m; Moving Mass Of Diaphragm (Mmd):163.5 g; Moving Mass(MMs):186.2 g; Reference Efficiency (No):0.0259; Mechanical Compliance (Cms):0.11 mm/N; EBP:109 Hz; Driver Displacement:434 in3. Mounting and Shipping Information. Overall Diameter:18.11"; Baffle Hole Diameter:16.57"; Bolt Circle Diameter:17.32"; Flange and Gasket Thickness:0.54"; Depth:8.01"; Net Weight(lb):22.3