Seems you and I have been doing a lot of conversing out here Donnie. Maybe we just have too much time on our hands or our projects are boring...
My sonotube sub is getting closer to complete. I need to figure out a grill for it and do a final coat with Duratex.
At first I was not impressed, but I let it play a while and then messed around with the amp settings. Those 2.1 chip amps with crossover, bass volume, mid/treble volume, and brightness can make just about any speaker sound OK to pretty good.
I gained some lower bass for sure. Its not overly loud running on just 12V but I imagine I will up that to 24. In order to get danceable bass, I may have to add a separate tube and maybe go to two amps.
I did acheive the goal of a lightweight "box". Its very lightweight so carrying it to the beach will be easy. I'm a little concerned about the tube getting dented but we'll see.