ok, so your new riser is a bass trap. but it looks like its covered with plywood all round except the bottom, if you were to fill it up with stuff, would the bass frequencies pass through the wood? Yeah. Its a ply wood top, with 2 by 8 sides and braces. It will still work, but I need to stuff it FULL. Insulation is for 2 by 4s, not 2 by 8s, so it gunna take alot. SheepStar