SIGMA PRO-18A 18" Professional Series Speaker- v.2

Recommended for professional audio as a woofer in vented enclosures. Applications  Subwoofer | Woofer | Pro Audio Box Type: Vented SpecificationsDownload Spec Sheet Download Cab Design SPECIFICATION Nominal Basket Diameter 18", 457 mm Nominal Impedance* 8 Ω Power Rating* Program Power 1300 W Watts 650 W Resonance 28 Hz Usable Frequency Range 41 Hz - 2.4 kHz Sensitivity* 99 dB Magnet Weight 120 oz. Gap Height 0.375", 9.5 mm Voice Coil Diameter 3", 76 mm THIELE & SMALL PARAMETERS Resonant Frequency (fs) 28 Hz DC Resistance (Re) 6.29 Ω Coil Inductance (Le) 1.9m H Mechanical Q (Qms) 8.28 Electromagnetic Q (Qes) 0.3 Total Q (Qts) 0.29 Compliance Equivalent Volume (Vas) 441.2 liters / 15.58 cu.ft. Peak Diaphragm Displacement Volume (Vd) 695 cc Mechanical Compliance of Suspension (Cms) 0.24 mm/N BL Product (BL) 22.1 T-M Diaphragm Mass Inc. Airload (MMs) 130 grams Efficiency Bandwidth Product (EBP) 93 Maximum Linear Excursion (Xmax) 6.1 mm Surface Area of Cone (Sd) 1140 cm2 Maximum Mechanical Limit (Xlim) 18 mm MOUNTING INFORMATION Recommended Enclosure Volume Sealed N/a Vented 93-212 liters / 3.3-7.5 cu.ft. Driver Volume Displaced 0.234 cu.ft. / 6.62 liters Overall Diameter 18", 457.2 mm Baffle Hole Diameter 16.56", 420.6 mm Front Sealing Gasket Yes Rear Sealing Gasket Yes Mounting Holes Diameter 0.28", 7.1mm Mounting Holes B.C.D. 17.25", 438.2mm Depth 8.15", 207 mm Net Weight 24.5 lbs, 11.11 kg Shipping Weight 28.1 lbs, 12.75 kgs MATERIALS OF CONSTRUCTION Coil Construction Copper voice coil Coil Former Polyimide former Magnet Composition Ferrite magnet Core Details Vented and extended core     Basket Materials Die-cast aluminum basket Cone Composition Paper cone Cone Edge Composition Cloth cone edge Dust Cap Composition Solid composition paper dust cap Frequency Response