My roomate is a builder, this was in the carport...

 

The cylindrical shape is the key to withstanding the pressure. I've seen prefab tube enclosures made of cardboard. It's a very dense, heavy-duty cardboard...not like a packing box.

 

do you guys really think that concrete round thing will work? i may try that. i would love to try somthing differant

 

They will definitely work. Go search sonotube on google...you'll find several audio forums that discuss their use. They are especially big with home audio guys.

Toby

 

And home audio is waaay ahead of car audio.

 

how about a wedge shape? where the subs would actually be on the smaller side and the box would flare out kind of and the bottom would be bigger.

 

You mean a cone shape?

 

well there are 2 subs...

ok sketch didnt come out lol

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/_\
obv this is a very BAD
scetch but it gives you the idea.... that would be a side view, all of the "walls" would be strait (as in not round) and the subs would be at the top.

 

It's hard to say. You start straying too far from the norm and it ends up really just becoming a guessing game. I'm assuming you'd like to stick with something tried and true rather than trial and error.