Ok, I'm going to attempt to build a box. I was just wondering about the bracing. Basically I have two 3/4" panels I can use for bracing. Should I glue both together, to have one solid 1.5" brace. I was thinking I would mount the sub off-center, so I could put the brace more toward the center (if I do it this way). Or, should I keep the sub in the center and use a panel on both sides?

Thanks for your help

P.S. If you need to know specs, it will be a 15" w/ 500w in a 2 cu. ft. box

It will all depend on the enclosure and how it's built to determine how/where/what bracing you will need.

I'm going to do a sealed box. 15.25"H x 22.5"W x 10"D (internal dimensions)

You might not even need any bracing. I ALWAYS use it, but it's not always necessary. I myself, would brace that enclosure, but as far as how, it would all depend on driver mounting and how much I felt it needed.

Now, if you build 4 sides of it and post some photos, we could better tell you how to approach it properly.

Ok, I'll see what I can do.