Brand NEW! 6-1/2" Poly Cone Midbass Woofer 4 Ohm This durable 6-1/2" poly cone woofer with rubber surround is designed to work best in small, sealed bookshelf-style cabinets. The damped poly cone creates smooth sound from 45 Hz all the way up to 3,000 Hz and is easy to integrate with many different tweeters, and the 4 ohm impedance extracts more current from an amplifier for twice the output (3 dB increase), when compared to a similar 8 ohm speaker. A 1" voice coil is combined with an aluminum former for a power handling rating of 30 watts RMS and 60 watts max, and the "Q" of the motor is such that solid bass performance can be achieved in cabinets as small as 0.25 cubic feet, with an f3 of 63 Hz (with a 1/4 pound of acoustic fill). Product Specifications Nominal Diameter- 6-1/2" Power Handling (RMS)30 Watts Power Handling (max)- 60 Watts Impedance - 4 ohms Frequency Response - 50 to 6,000 Hz Sensitivity - 88.3 dB 2.83V/1m Voice Coil Diameter - 1" Thiele-Small Parameters Resonant Frequency (Fs) - 52 Hz DC Resistance (Re) - 3.37 ohms Voice Coil Inductance (Le) - 0.48 mH Mechanical Q (Qms) - 2.99 Electromagnetic Q (Qes) - 1.4 Total Q (Qts) - 0.95 Compliance Equivalent Volume (Vas) - 0.65 ft. Maximum Linear Excursion (Xmax) - 3.5 mm Materials of Construction Cone Material - Poly Surround Material - Rubber Voice Coil Wire Material - Copper Voice Coil Former - Aluminum Basket / Frame Material - Steel Magnet Material - Ferrite Mounting Information Overall Outside Diameter - 6.5" Baffle Cutout Diameter - 5.625" Depth - 2.875" Bolt Circle Diameter - 6.125" # Mounting Holes - 4 Optimum Cabinet Size (determined using BassBox 6 Pro High Fidelity suggestion) Sealed Volume1.53 ft.Sealed F349 Hz Vented Volume3.64 ft.Vented F330 Hz - All international buyers are responsible for all tax, duties and/or customs fees.