just a sub for music and I'm not really into having the music punch me in the chest so just something to pick up the lows that the stand speakers don't do at low to moderate volume levels
the prices at speakerhardware.com are really good.
Have you considered some stand subwoofers? Like this Babgy design... https://meniscusaudio.com/product/kairos-woofer-module-full-kit-pair/
If the premise works, I have a couple of comparable designs that are less expensive. It does give the advantage of 2 subwoofers without taking much additional space.