1st time Subwoofer owner: I need some tips/modding advice please!

Lol what the hell, it’s free so why not!

Not just free but effective. It’s a common thing to do to get rid of boominess (and get better control) on ported woofers. It’s not the same as a properly sealed enclosure but it gets you close.

Good to know! I can already tell I’m going to start going down the very damp, dark, rabbit hole…