Thanks smokarz. There are many online calculators for both round and square/slot ports, the formula for doing it on paper, and WinISD. I used all three to triple check my work to make it as exact as I could. Since my TD12M is only in 1ft^3, the port volume and driver volume would make a significant impact on final volume and response curve. Wayne Parham mentioned this, that in larger cabinets "less precision" is needed. You can see this evendenced by the minute changes in simulated response with larger volumes, though I've never measured this, I'll take Wayne's word for it.
The enclosure is 14.5"W 16"H 13.5"D with double baffle, 50Hz tune, 2-chamber cabinet (waveguide and woofer separate), 1ft^3 with slot port 12"W 1"H 10"D (~120in^3) plus driver volume 0.1in^3. With the double baffle the inner port length is reduced which gives me enough room for the 1" donded Dacron lining to not interfere with port mouth. There are no braces since the box bottom, port structure, and box top (bottom of compression driver chamber) are in such close proximity, it's very solid. I finally finshed the second one and have been listening in stereo for a week.
Here's a couple shots of the port and baffle before the sides were installed. The first time I assembled everything at once, port, sides, bottom, top. everything. On the second speaker installing the port first was way easier.
Anyway, you're close though, man. You may as well order the xo components and build the crossover while you decide on the enclosure. Once you've got the particulars sorted out, you'll be making sound soon!Edited by robotbunny - 11/1/12 at 10:21am