4 Inch Subwoofer

Simple 4 Inch subwoofer using a Dayton Audio 4" long-excursion driver in a ported box. The box is braced and printed at 50% fill, although the brace is printed with 80% fill. I used cotton stuffing on the back and top wall near the driver. The box is tuned to 50Hz and with room reinforcement, it provides nice bass down to 40Hz or perhaps a bit lower. I created passive and active versions. The active has a 30/30/60w or 50/50/100w plate amplifier and the passive has holes on the rear side for a pair of spring loaded binding posts.

4 Inch Dayton Audio Speaker Driver
https://www.parts-express.com/Dayton-Audio-TCP115-8-4-Treated-Paper-Cone-Midbass-Woofer-8-Ohm-295-416

Bluetooth 5.1 Plate Amplifier
https://www.aliexpress.us/item/2255799823670271.html

Speaker Terminals (Passive Version)
https://www.aliexpress.us/item/2255801103439930.html

Subwoofer Crossover (Passive Version)
https://www.aliexpress.us/item/2255800533711868.html

Cotton Fiber Insulation
https://www.amazon.co