Electronics-Expo.com offers the Polk Audio DSW PRO 500-watt 10" Powered Subwoofer
, model no. AM6075-A, for $499. Coupon code "BIGBEN" drops it to $318.24
. With $29.99
for shipping, that's $29 under our October mention and the lowest total price we could find by $131. It features a 23Hz to 160Hz frequency response, 500 watts of peak power, downward firing slot port, and more.