Warp,
I wish I had a CAD program so I could show you some of my designs. I do them all free hand right now
but they work wonderfully. I think you would really like my W7 build plan I have about ready to go. My 12W7 (5.25 cu.ft. net, tuned to about 19hz with over 45 sq. inches of port area, External dimensions of 18.5" W x 26.5" H x 32" D) is going to replace my PB-12 Ultra. It is going to stomp it in terms of linear output. I will probably do a second one, if things go as planned. I will be using a Behringer EP2500 in 3 ohm two channel mode (700-900 watts rms each) with the Behringer DCX 2496 for tuning/x-over purposes.
The part that stinks is that it will probably weigh approximately 150 lbs. with the driver. Oh well, that is what casters and plastics sliding feet are for
.
To the OP:
Doing a simple box-within-a-box is not going to do your new sub system any justice without adequate bracing. Yes, some of the designs look complicated, but without adequate bracing and the like, it does not get you the full result.
Essentially, if you're going to put the time into a DIY build, try to do it right (to the best of your ability) the first time. DIY is a hobby that takes time and experience to perfect. When I look back at my first enclosure (which someone is still using
) I laught at how poorly constructed it was compared to the ones I have done somewhat recently. With the help you can get from those of us here on the design and such, your first enclosure will be 100x better than my first.
Keep your head up and don't be intimidated by complex looking plans, it's just wood, glue, & screws