Amazon offers the Sony Performance Line 10" 100-watt Powered Subwoofer in Black, model no. SA-W2500, for $58.79 $59.99 with free shipping. That's a buck under our mention from four days ago and the lowest total price we could find by $69. It features a 28Hz to 200Hz frequency response, 100-watt amplifier, and 10" mica-reinforced cone woofer.