Brand NEW! Including 90 Days USA Factory Warranty. Dayton Audio PA Series Pro Woofers are a great upgrade for musical instrument or sound reinforcement cabinets, and also excel in custom-built speaker systems. Key Features Strong, low-mass carbon fiber impregnated paper cone I-beam rolled edge 1.5 mm steel frame Low distortion motor system w/copper cap Powerful 80 oz. ceramic ferrite magnet Vented pole piece/vented voice coil gap improve thermal management Black motor parts and black polyimide voice coil former dissipate heat Bumped back plate for unrestricted excursion Dayton Audio PA Series Pro Woofers are a great upgrade for musical instrument or sound reinforcement cabinets, and also excel in custom-built speaker systems. High power handling, smooth response, low distortion, deep punchy bass, and rugged reliability are the features that set PA Series woofers apart from other drivers ? premium performance, but value priced. Product Specifications Nominal Diameter 18" Moving Mass Of Diaphragm (Mmd) 171 Power Handling (RMS) 500 Watts Power Handling (MAX) 1000 Watts Impedance 8? Frequency Response 26 to 2,000Hz Sensitivity 97.8dB 2.83V/1m Voice Coil Diameter 3" Thiele-Small Parameters Resonant Frequency (Fs) 28.3Hz DC Resistance (Re) 5.6? Voice Coil Inductance (Le) 3.9mH Mechanical Q (Qms) 11.2 Electromagnetic Q (Qes) 0.34 Total Q (Qts) 0.33 Compliance Equivalent Volume (Vas) 14.19ft Mechanical Compliance of Suspension (Cms) 0.19mm/N BL Product (BL) 22.3T·m Maximum Linear Excursion (Xmax) 6mm Surface Area of Cone (Sd) 1241.1cm Materials of Construction Cone Material Paper / Carbon Fiber Surround Material Cloth Voice Coil Wire Material Copper Voice Coil Former Kapton / Polyimide Basket / Frame Material Steel Magnet Material Ferrite Mounting Information Overall Outside Diameter 18.11" Baffle Cutout Diameter 16.73" Depth 7.8" # Mounting Holes 8 Optimum Cabinet Size (determined using BassBox 6 Pro High Fidelity suggestion) Sealed Volume 2.73ft Sealed F3 72Hz Vented Volume 5.68ft Vented F3 47Hz - All international buyers are responsible for all tax, duties and/or customs fees.