Eighteen Sound 18NLW9601-8 Extended LF Neodymium Driver 18-inch with Carbon Fiber Reinforced Cellulose Cone 8 Ohms 1800 Watts RMS 3600 Watts Peak || HIGHLIGHTS || 96 dB SPL 1W / 1m average sensitivity || * 135 mm (5.3 in) split winding four layers ISV aluminum voice coil || * 3600 W program power handling || * Carbon fiber reinforced cellulose cone || * Double Silicon Spider (DSS) for improved excursion control || * Aluminum demodulating ring (SDR) for lower distortion || * High force neodymium magnet assembly || * Weather protected cone and plates for outdoor usage || Suitable for reflex, bandpass or horn loaded high SPL subwoofer systems || || "SPECIFICATIONS || Nominal Diameter : 462 mm ( in) Nominal Impedance : 8 Ω Minimum Impedance : 6.1 Ω Nominal Power Handling1 : 1800 W Continuous Power Handling2 : 3600 W Sensitivity3 : 96.0 dB Frequency Range : 30 - 2300 Hz Voice Coil Diameter : 135 mm (5.3 in) Winding Material : aluminum" || THIELE SMALL PARAMETERS || Fs 39 Hz || Re 4.7 Ohm || Sd 0.113 sq.mt.(175.15 sq.in.) || Qms 5.70 || Qes 0.30 || Qts 0.28 || Vas 120 It.(5.79 cuft) || Mms 255 gr.(0.6 Ib) || BI 31 Tm || Linear Mathematical Xmas +/-14 mm (+/-0.55 in) || Le (1kHz) I 2.19 mH || Ref.Efficiency 1W@1m (half space) 95.6 dB || Suitable for reflex. bandpass or horn loaded high SPL subwoofer systems || AES Power 1800W || Peak Power 10000W || Frequency Range 30 - 2300 Hz || Power Compression @-10dB 0.7 dB || Power Compression @-3dB 1.3 dB || Power Compression @@Full Power 2.2 dB || Max Recomm.Frequency 300 Hz || * Recomm.Enclosure Volume 110 - 350 It.(3.89 - 12.36 cuft) || Minimum Impedance 6.1 Ohm at 25 DegreesC || Max Peak To Peak Excursion 70 mm (2.75 in) || Voice Coil Diameter 135 mm (5.3 in) || Voice Coil winding material Auminum || Suspension Triple Roll.Heavy Polycotton || Cone Straight ribbed carbon fiber loaded cellulose || MOUNTING INFORMATION || * Overall diameter : 18.18 in || * N.of mounting holes and bolt 8 || * Mounting holes diameter : 0.33 in || * Bolt circle diameter : 1732 in * Front mount baffle cutout diameter : 16.38 in || * Rear mount baffle cutout diameter : 16.61 in || * Total depth : 9.29 in || * Flange and gasket thickness : 1.02 in || * Net weight 12.8 kg (27.6 Ib) || * Shipping weight 14.3 kg (31.50 Ib) || * CardBoard Packaging dimensions : 18.98 x18.98 x10.12 inch ||