FEATUTRES: [Â Throat Size 1", 25.4 mm [Â Nominal Impedance 8 Ohm [Â Power Rating 80 W (EIA426B Secification, 1.6 kHz 18 dB) [Â Resonance 550 Hz [Â Usable Frequency Range 1.2 kHz - 20 kHz [Â Recommended Crossover 1.2 kHz / 18 dB or 1.8 kHz / 12 dB [Â Sensitivity (1 W 1 m on axis horn) 105 dB [Â Magnet Weight 34 oz. [Â Voice Coil Diameter 2", 51 mm [Â Re 6.1 [Â Le 1.6 mH [Â Overall Diameter 5.25", 133 mm [Â Mounting Holes Diameter 2X 1/4-20 or 3 x M6 [Â Mounting Holes B.C.D. 3" or 2.25'' [Â Mounting Thread 1 3/8" 18 NEF ext. [Â Depth 2.2", 56 mm [Â Weight 5 lbs, Gross 5.76 lbs [Â Voice Coil Former [Â Diaphragm Material