Klipsch R-12SW Powerful Deep Bass Front Firing 12" Copper-Spun Driver 400W Digital Power Subwoofer 14" X 18.5" X 16"

that's a really, really tight budget, dude. save and double that, then you can do something. -sub -amp -enclosure -wiring/power/ground/etc. -maybe a LOC you need more than $300 to cover all those basics, unless I'm unaware of supplies you already possess. edit: you didn't say home theater. https://a.co/d/0ixkIPrh