Brand NEW! The Tang Band W6-1139SIF 6-1/2" driver will surprise and impress when installed in subwoofer systems for compact home theater systems, multimedia setups, and mobile audio installations. Key Features ? 11.5 mm xmax, amazing low frequency capability for a driver this small! ? Wide half-roll surround, raised flat spider, and large 1-1/2" 4-layer voice coil ensure exceptional output ? Vented pole piece and vented spider promote voice coil cooling ? Features a rugged stamped steel basket and bumped back plate The Tang Band W6-1139SIF 6-1/2" subwoofer's wide half-roll surround, raised flat spider, and large 1-1/2" 4-layer voice coil ensure exceptional output and high power handling. Boasting 11.5 mm of Xmax, the W6-1139SIF is capable of producing prodigious amounts of deep, low-distortion, punchy bass. A vented pole piece and vented spider promote voice coil cooling by improving heat dissipation and reducing efficiency-robbing power compression. This 4 ohm driver also features a rugged stamped steel basket and bumped back plate. Product Specifications Nominal Diameter 6-1/2" Power Handling (RMS) 50 Watts Power Handling (MAX) 100 Watts Impedance 4? Frequency Response 35 to 800Hz Sensitivity 83dB 2.83V/1m Voice Coil Diameter 1.52" Thiele-Small Parameters Resonant Frequency (Fs) 35Hz DC Resistance (Re) 3.6? Voice Coil Inductance (Le) 0.47mH Mechanical Q (Qms) 2.65 Electromagnetic Q (Qes) 0.47 Total Q (Qts) 0.4 Compliance Equivalent Volume (Vas) 0.42ft Mechanical Compliance of Suspension (Cms) 0.6mm/N BL Product (BL) 8.47T·m Diaphragm Mass Inc. Airload (Mms) 39.91g Maximum Linear Excursion (Xmax) 11.5mm Surface Area of Cone (Sd) 140cm Materials of Construction Cone Material Paper Surround Material Rubber Basket / Frame Material Steel Magnet Material Ferrite Mounting Information Overall Outside Diameter 6.95" Baffle Cutout Diameter 5.57" Depth 4.33" # Mounting Holes 4 Optimum Cabinet Size (determined using BassBox 6 Pro High Fidelity suggestion) Sealed Volume 0.13ft Sealed F3 70Hz Vented Volume 0.33ft Vented F3 38Hz - All international buyers are responsible for all tax, duties and/or customs fees.