W3v3 8-inch Subwoofer (250 W, 4 ?) If you need an 8-inch subwoofer that can create outstanding bass in extremely small enclosures, the 8W3v3 will do the job and surprise you with its power and accuracy. It employs the same technologies as its larger diameter brethren to deliver a whopping 0.375 in. (10 mm) of controlled, one-way, linear excursion. The 8W3v3-4 is best used with amplifier power in the 75W - 250W range and is optimized to operate in a tiny 0.30 cu. ft. (8.5 l) sealed enclosure, or a 0.35 cu. ft. (9.9 l) ported enclosure.