Amazon.com: KRK S8.4 8 inches Powered Studio Subwoofer Class D Power amplifiers 4-Position Crossover Frequency and 109 watts of Power with Pair of EMB 1/4 in Cables and Magnet Phone Holder Bundle :
Used KRK S8.4 Subwoofer | Guitar Center
KRK S8.4 8" Powered Studio Subwoofer Generation 4 S8 Sub Class D - Walmart.com