Is that 1in mdf?
I'm diggin the build. I put up very similar #'s in MECA AS3 Ohio Finals a few weeks ago. I'm on stock elec with a 130a alt and voltage dropping to 11.8 (//content.invisioncic.com/y282845/emoticons/help.gif.cee8f684da1ba626487a8bc51152e1ec.gif) and no sound dampening but I'm pretty sure I can break a 40.
I cant wait to see how the quads end up //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
edit: forgot to ask how much did the spl meter set you back?