A best bet is the Klipsch Reference 10" Powered Subwoofer in Satin Black, model no. SW-311, for $1,099. Coupon code "CLEARANCE" drops it to $699.99. With free shipping, that's tied with our mention from two weeks ago and the lowest total price we could find by $700. It features 500 watts continuous power, dual 10" woven fiberglass drivers, frequency response of 22Hz to 120Hz, digital controls, five system presets, and Klipsch's Adaptive Room Correction II with 12 active filters.