World Wide Stereo offers the Klipsch SW-311 Reference Series 500-Watt Subwoofer System in Satin Black, model no. 1011473 for $599. Coupon code "TECHB311" cuts it to $489. With free shipping, that's $11 under our mention from three weeks ago and the lowest total price we've seen for this subwoofer. (It's a current price low by $161.) It measures 13" x 13" x 14" and features ARC II technology, BASH digital hybrid amplifier, frequency response of 22Hz to 120Hz, and 10" drivers.