As one of its daily deals, Newegg offers the Polk Audio 300-watt 12" Powered Subwoofer in Black for $179.99. Coupon code "EMCSRFCH5" cuts it to $159.99. With free shipping, that's the lowest price we could find by $20, although we saw this for $10 less in December after a rebate. It features a frequency response of 23Hz to 160Hz, magnetic shielding, phase switch, and adjustable crossover. Deal ends today.