Thanks, Wayne. I have put in the braces on all four sides...I haven't stuffed it with fiberglass yet though, and I haven't mounted the back panels. I'll do as you suggest. It looks from your picture as though you stuff the angled areas around the horn pretty thoroughly?Also, do you use some kind of strip to seal the back panel to make the entire cabinet airtight? I couldn't see anything on the picture with the ball braces.
tim