Newegg offers the Klipsch Synergy 12" 105-watt Powered Subwoofer
, model no. KSW-12, for $159.99
for shipping. That's tied with our September mention, although that was with rebate hassles, and the lowest total no-rebate price we've seen. (It's also a current low by $29.) It features a 12" down-firing driver, variable crossover, two line level/LFE inputs, switchable phase, and a continuous power rating of 105 watts.