In this video, we'll be building the PSS555 21" subwoofer. We'll be powering it with a class D desktop amplifier.
Dayton Audio PSS555 21"
https://www.parts-express.com/Dayton-Audio-PSS555-8-21-Pro-Subwoofer-with-4.5-Voice-Coil-8-Ohm-295-050?quantity=1
Fosi Amp
https://fosiaudio.com/products/bt30d-bluetooth-5-0-2-1-channel-power-amplifier-with-bass-and-treble-control