Quote Originally Posted by dave_bullet
PS: - don't forget to allow for feet in your tower design - these can be 1"+ if you use spikes

I like the idea of a shelf on an angle. Help break up panel resonances.

I notice with the Madisound kit they give you foam for the walls. Should you still stuff with batting / acousta-stuff? If it helps absorb unwanted midrange from escaping from the port - fine, but if it is just to make the box appear bigger for the woofer (which stuffing does by roughly10%) , I can do that by moving my partition down the cabinet.
I'm not sure I'm qualified enough to answer you question. It would seem to me that you could get some undesireable effects from standing waves, etc if you increase the interior volume of the "top part" of the cabinet by dropping that partition. I know some people have made larger cabinets for these with poly-fill, acousta-stuff, etc, and reported good results. I think you would want to keep the 13 inch height the same, at the very least, and maybe use bracing every 8" or thereabouts to limit resonance problems. I wouldn't want to go much more than 13" without a brace.

After a few discussions with some other people last night I think I'm going to abandon the sand filling idea and just use 3 or 4 "donut" and "H"-braces in the lower cabinet to cut down on resonance. Might stuff it with pink insulation, poly-fill, or something cheap so there's no "hollow" sound.