Thanks guys!
Nate - the tube is very simple to make. The cylinder part is Quik Tube, which is for pouring concrete footings, so I bought that at Lowe's. They had 2 choices, 8 inch and 12 inch, but the 12 wouldn't have fit where I wanted it. Also, I liked how the sub was a perfect, flush fit to the tube. I think the original brand is called Sonotobe, but they didn't have that. Anyway, I just cut the tube to make the desired volume. Then the top and bottom is 3/4" particle board. I was going to use MDF, but they only had huge pieces and they saw was broken. They are attached only by Liquid Nails. Weird, huh? That's what the book I had suggested, and it works really well! I was surprised. And then I carpeted it and installed the speaker terminal. And the sub is just screwed on.
I'm not sure what you mean by 'supports.' You referring to the metal braces? I just screwed those into the top particle board and the cardboard, which a dab of Elmers Glue-All for insurance.
Oh, and I beleive that they smaller hole on the right is a leftover from the Mondeo. Seems that they have an option for a small woofer.