Powered subwoofer for MSP speakers, 180 watts, 10 Inch woofer
Single 18 Inch subwoofer
Powered subwoofer, 800 watts, 15 Inch woofer
10" BASH sub from the now-defunct TSC.
This is a high quality Koss Subwoofer. It features 6 Ohm Impedance, 100 Watt Power, a 7" woofer, Super Bass Woofer, and a Passive Design.