TW5v2 13.5-inch Subwoofer (600 W, 4 ?) We couldn’t leave the ultimate thin woofer alone... we had to make it even better. Our patented thin-line woofer technology compresses the architecture of the 13TW5v2 using a “concentric tube” structure that supports the 7-inch diameter voice coil and the suspension attachments. This permits placement of the large motor structure much further forward in the speaker than with conventional designs, while allowing excellent linear excursion capability and mechanical stability. To unleash even more performance from this technology, the v2 improves upon the original 13TW5 with 13% greater linear excursion capability. The cast alloy chassis has also been modified for greater strength and the redesigned motor now features an annular vent. The v2 is also available in single 2 ohm and single 4 ohm voice coil versions to fit a wide range of applications. In keeping with its “tight-spaces” mission, the 13TW5v2 is optimized for enclosures that are far smaller than most 12-inch woofers require and only a bit larger than the air space needs of a typical, small-box 10-inch woofer. The mounting system is designed to fit in about the same footprint as a typical 12-inch woofer. The 13TW5v2 is best used with amplifier power in the 250W - 600W range and is optimized to operate in a 0.80 cu. ft. (22.7 l) sealed enclosure. Never has such high-quality sub-bass been possible in the most challenging installation applications.