Beautiful! thanks for sharing! Inspiring! I wish one day I could build stuff like this!
Thanks! I'm sure you could build your own things--the sub wasn't "actually" rocket science

and I made up some of the parts as I went. Mostly it's about being willing to just start and learn as you go. It's amazing what you can achieve even with just a few handheld power tools and a positive attitude!
The other aspect is not choosing to learn with project implementations that require too much perfection. An example here is that I wanted an ugly cardboard tube to look modern and elegant, and I didn't want to spend my life filling and sanding and fighting painting drips. While it had its own challenges in handling (see the build thread), the laminate ironed out almost the entire tube in one feel swoop, likely adding additional damping and stiffness via the rubbery contact cement and stiff laminate material at the same time.
I knew it would be hopeless to get the edges of the laminate to line up almost perfectly where they joined, so I deliberately designed my stand to allow tons of slop and clean it all up with essentially no further effort.
Here you can see what I mean... lots of gap that massively reduced the need for precision. This aspect of planning ahead can save massive headaches later.

The laminate and tube were also cut a bit long, then (carefully) trimmed back to the desired length at the last possible moment, which also helps avoid damage to the ends in handling. It's super easy to bash the ends of a 6' tube into anything and everything.

The spine covered up the laminate gap just by attaching its 4 bolts, and poof, gone. Then the power and signal cables got routed up the interior of the spine to keep things clean externally while avoiding the addition effort/hassle/limitation of routing them inside the sub chamber (which I did consider).

Plan to make your life easier on yourself and just go for it!