Info in the imgur link above, but wanted to test Hornresp to see if it worked, I was pleasantly surprised that it did along withe the horn folding workbook from Brian Steele.
Enclosure fits on a 4x8 sheet of ply. Used an old car subwoofer I had laying around, CVR8 from 2005ish.
Biggest issue I has was an air leak where the baffle butted up to the front panel, couldn't get in there to adequately seal after it was assembled.
Building this cabinet gave me the confidence to build an 18" tapped horn and then many other ported fullrange and subwoofer designs for large venue applications.