Let's Design A 2x12 Cabinet.

[GoldenVulture]

Air tight boxes create a damping on the speaker cone movement so it's excursions aren't too big.
Pretty usefull with high volume/wattage amplification.

:old:

[Dr. Vegetable]

GV is correct. A ported cabinet can "crash" the speaker driver because it won't limit the excursion as much. A sealed cab will push back against the speaker as it moves further.

Porting is kind of like having an open back in that it helps to reduce the sharp lobe you can get off the front of the speakers to distribute the sound a little more evenly.

I'm not sure if I would port a guitar cab or not. But I thought the pics showed some pretty good construction techniques no matter what other design choices you make.

To be clear, those pics I linked were the results of a google search, not something I built or own. I have trouble cutting out nice round holes for the speakers, and it's all downhill from there.

[lreese]

Would THD cab dimensions help? I've got one on my shelf.

[Big Flannel]

I can give you measurements from my cab but it is a monster. It's bigger than the oversized Orange 2x12 cabs so you may not find it useful unless you have room for a fridge in your jamspace lol

[karpathion]

Yes it would if you care to measure.

Looks like I'm SOL on the pine. Not one lumber store in town has anything over 12" wide. I need at least 14" minimum. To special order 16" void free is about 3 times the price as 12". I can buy an unloaded 2x12 on fleabay for what the lumber alone would cost. 

I need a new material. The only birch I can find in town is 7 ply. It would work, but that stuff will have little voids all in the inner plys. The 11 ply has much less.

I did find some nice Aspen wood, multi piece planks that are 15".  They are pieced and glued together like a hard wood floor. Each smaller piece is about 2"x5". Very uniform and Void free. I can even get pieces wide enough for the baffle and rear panel. I'll have to do some research, but that might work.

I did get the speakers today. The temptation to mix one with a Swamp Thang, in one of my 1x12 cabs is brutal. I may just have to try that out until I get this 2x12 done.

[karpathion]

I can give you measurements from my cab but it is a monster. It's bigger than the oversized Orange 2x12 cabs so you may not find it useful unless you have room for a fridge in your jamspace lol

Yeah, that would be awesome! I don't mind big. My  1x12s side by side are bigger than any 2x12 I've ever seen.

[GoldenVulture]

Back in the 70's Marine Ply was very popular for speaker boxes.

[lreese]

I had a conversation with my repair guy about sourcing wood - He said you can order the good plywood through Lowes if you want to go that way. That was a couple of years back, so things might have changed.

[karpathion]

Change of plan. I'm going to use the 12" VF pine. I just have to change the specs closer to a 1936. It'll be 30" x11.75" x 22". Almost exactly the shape and size of a 1936. I'll be picking up materials in the morning. I'm ready to get this thing rolling.

[Oinkus]

Not a bad plan to use 1936 is a good cab. Marine ply is a good alternative as GV already said.