SPECIFICATION:MODEL:TRF LSW158D1 Size: 15 Cone: Competition  Grade Paper Surround material: Foam Voice coil: 3.0inch Voice coil layer: 4layer Nominal impedance:dual 1ohm Voice coil wire:Coper RMS Power: 800wrms MAX Watt:1600wmax Sensitivity: 89.2dB Resonance frequency(f0): 33.1Hz Mechanical Q factor(Qms): 5.98 Electrical Q factor:(Qes):0.63 Total Q factor:(Qts): 0.57 Xmax: 15mm Force factor: 15.8N/A Magnet Weight: 110 Oz   1=Outer Dimension:  393mm - 15.47" 2=Mounting Depth: 185mm - 7.28" 3=Magnet Dimension: 176mm - 6.90" 4=Mounting Hole Dimension: 350mm - 13.78"