Once upon a long while ago, I bought a pair of Speaker Lab 2 way raw kits for my first 'outside the box' diy cabinets.
Based on a top half of the curved back of the capital R with same proportion face width of the box designed for those drivers, just taller to keep the cubic volume the same. Out of oak strips for the curve....Clear oil finish...
Sounded better than they deserved to.
Have pics, but the speakers ended up with a my landlady when she bought an AR table at my suggestion and I bought the 901's....to her later dismay...
"Jerry....do you realize I can hear your stereo over mine....indoors...?"
oh.... *L*