I just had a great conversation with the guy at Stereo Integrity, and he only laughed at first. But he said that he thought that the idea of a six-foot tube with opposing HS-24 at each end was a fabulous idea. He confirmed that the 16-20 cubic feet is the recommended internal air space for each driver, but he said that the HS-24 is so flexible that it works in tighter spaces. He said that he has never had anyone actually set up a pair of HS-24 in a container with the recommended space and would really like to know the results.
So now I seem to have an unusual but not so crazy idea. Unless anyone knows of other subwoofers that were made with 40 cubic feet of internal space. And $1,279 times 2 plus $250 for the laminate tube is less than I expected for the starting costs. I know there will be more, just have to itemize and figure it out. This now seems doable, but am I going to need a second when it is done?