SVS SB16-Ultra 16" 1500W Subwoofer SB16-ULTRA-BLACK OAK B&H
Amazon.com: Seismic Audio - 15" Raw Speaker Woofer Replacement PRO AUDIO PA/DJ 16 Ohms : Musical Instruments
BOSS Audio Systems B12ES 12 Inch Powered Car Subwoofer Package - 600 Watts Max, Built-In Amplifier, Low Profile, Remote Subwoofer Control (16 ft Cable) - Walmart.com
DIY 16hz sub bass horn - The Paper Horn by Inlow Sound