Harman Audio offers the factory-refurbished Infinity Primus PS38 8" 150-watt Powered Subwoofer in Black for $99.99 with free shipping. That's $100 off list and the lowest total price we could find. This 8" woofer features a 35Hz to 150Hz frequency response and 150-watt RMS amplifier (300 watts peak). A 1-year Harman Audio warranty applies. Deal ends September 18.