I have never built this type of sub, but I just recently acquired a heavy duty mailing tube, 12 " internal diameter, with 3/8" walls. If my math is right, I will have 3 cu ft to work with. I know it's not ideal for LLT, but what drivers do you guys think would be a candidate. I would assume with the 12" diameter, I will be looking at 10" subs. Thanks for any ideas.