interesting idea: marble box ...

[Pokey]

Very true, but I'm not talking about 3/4" metal plate here....maybe 3/8" at the most. Yeah it would still be heavy, but I'm thinking just the box, w/o sub, would prolly weigh about as much as my current box w/ sub installed. And that's about 50-60 lbs.

[Guest MegaloManiac]

with a metal box, for some reason i can see you getting a metal sounding bass

Concrete?

doesnt concrete crack?

[Ernesto]

people already use concrete in some of the comps here in california for boxes, ive seen at least three in person

Did you get to hear it?

[AI James]

yea loud as hell but weighed itn at about 10k lbs

[Pokey]

It will crack if you don't let it set long enough before stressing it. Concrete only cracks at spots that are thin/weak or an area that has air bubbles around it.  But I ain't tryin to work with concrete. 

[Amalan]

yea steel wont be that much heavier than mdf

[Pokey]

So you think maybe 3/8" steel plate would work good for a trial box???

[AI James]

lol 3/4 steel and 3/4 mdf not even close to same weight

[Amalan]

yea but 3/8 steel vs 3/4mdf will be somewhat close in weight

So you think maybe 3/8" steel plate would work good for a trial box???

probably not sure tho

[Pokey]

Maybe 1/2" steel would be closer to 3/4" MDF. But then I risk having too much flex from not enough thickness. I think 3/8 would be the best bet. It's only for one 12. 3.06 cubic ft is what's recommended for this sub.