OSD Black Trevoce 15EQ DSP 1500W Triple 15' Woofers with Native EQ & App Control DSP Room Correction : OSDAudio.com
DIY 16hz sub bass horn - The Paper Horn by Inlow Sound
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
Power 16" T2 Single 2-Ohm Subwoofer | Rockford Fosgate ®