My current project is to build some subwoofers that will be identical in outward appearance to my Oracles, and contain 2 each JBL K140s. I know that this driver isn't ideal for use as a sub, but I have 4 (although 1 might be a D140, can't remember) of them gathering dust, so it's what I'm going to use. I have tinkered online with several calculators, and still don't have a firm grasp on the particulars.

My basic idea is to take a box of this design,

And orient them port-to-port within the confines of the Oracle cabinet. Can anyone offer some more precise values regarding tuning of the box, port, etc? TBH, I'm not even sure on how to select the basics, i.e. box frequency and so on. Part of the difficulties I ran into way trying to calculate the changes due to the trapezoidal box shape. The picture I linked was as close as I could get with that calculator.

Any help would be appreciated.

I too would be interested in finding someone who could build them, as I have seen several posters turn up goose eggs trying to find custom cabinet builders. I did have my WTB in the marketplace, but that seems like a long shot.