Amazon.com: Monolith 16in THX Certified Ultra 2000 Watt Powered Subwoofer (Matte Black/Painted) Low Distortion, for Studio and Home Theater Systems : Electronics
Monoprice Home Speakers and Subwoofers for sale | eBay
Monoprice Unveils New Monolith THX Ultra-Certified Powered Subwoofers | audioXpress
Amazon.com: Monolith M-IWSUB82 Dual 8in in-Wall Subwoofer| Passive, Magnetic, Paintable Grille, Easy Install, Adds Powerful Bass to Your in Wall or in Ceiling Home Theater System : Electronics
Monolith By Monoprice Audition T5 Tower Speaker (Each)