Ok...last night I sat the directions for Adire's CAD and read for literally 4 hours last night. For my 15" Tempest Adire recomends 8 cubic feet of space. That equals 226.56 leters. So when I'm building it I'm planning on mounting my amp flush like Warrick so I must and make the tub a bit taller, to compensate for the space it takes up in the tube, right? Anyway Adire also recomends using 2 4" ports. So I pluggged that all in (two 4" ports, 12" long). I would prefer to use one bigger port but I can't find any flared ports bigger than 4" Would I be able to get say a 15" grill and cover them both? My favor (Tom begs mercifully) is if you guys would let me e-mail you my .box file so you can check out all the graphs to make sure things look ok. I checked out http://www.quux.net/roo/diy/sonosub/ and read his info and my pics look pretty much like his but I just want to make ausre before I embark on my journey. Once again...PLEASE..this is too important for me to mess up!