Crazy idea, any thoughts?

[Tachyon]

Hell yea! I made a tube for my old single cab Toyota out of the cardboard tube used to form concrete pillars. Used plywood on the rear and mdf for the speaker side and fiberglassed it. Ran a 8" Fosgate on ~450w. Sounded great.

I would think you might want more than glue holding the pipe to the wood?

Definitely. I was planning to drill and tap the pipe and put in screws as well. I'm also tempted to cut out the wood to fit the ends of the pipe snugly and glue it in then screw it in from the sides.

 

[Firewalker]

Lot's of people have used sanded pine with no issues.

 

[Tachyon]

Post picts when you're don't I'd like to see how it turns out. I like fun stuff like this audio experiments! My fave

Yeah, me too. In fact I've been really tempted to put a "snorkel" on this tube with a screw on cap so I can choose between a sealed or ported enclosure. Basically a hole in the side near the back, a short piece of 2 or 3" ABS, a 90° elbow, and another length of pipe that reaches to the front panel. From the front (speaker end) it would look like an 8 or a snowman. I decided to keep it simple with a sealed enclosure, but I'm definitely putting that idea on the back burner for a future project.

 

[Bobbytwonames 5,000+ posts]

A good 6-½" would work. The VFL 6-½".

 

[Tachyon]

A good 6-½" would work. The VFL 6-½".

Already got the 8" in hand, but yeah 6.5's can be made to work. I once did a system in a Porsche 944 with 6.5's. The guy wanted to upgrade the system without modifying the car or making it obvious it had a custom stereo. Did a pair of Kicker 6.5's in a sealed cabinet that was the shape of the rear cargo space floor and just an inch taller than the depth of the kickers. Put flush grills over them and covered them with matching carpet. You couldn't tell they were there. It only raised the floor a few inches. That speaker box had a cubby hole in it hiding a Linear Power amp driving them.
Replaced the stock door/dash speakers with Polk Audio's and Boston Acoustics equivalents. Drove them with a Concord amp hidden under the dash, and of course replaced the factory deck with a higher end Blaupunkt model. Those little 6.5's really pumped out nice tight bass. Perfect for what he wanted.

 

[Tachyon]

I got the wood and had them cut it....

OK so now I'm debating how to build this as far as the layout.
My original thought was to put wood end caps on it. Square ones. That way it can't roll around. I was going to make them large enough to mount the amp I already have for it on the back end, opposite the speaker. But lately I've been questioning that idea. I'm thinking of making the end caps much smaller, and mounting the amp separately. Or even making the end caps more bell shaped. With one flat side to sit on the floor.

Any other ideas?