Finally an example of an OB that gives some consideration to edge diffraction. Even though I believe it takes Olsen's work at little too literally, it has to be worlds better than 90 degree edges or small roundovers. If you tweak the design a little with bracing in the lower section and smooth rear area around the main driver, then you have a very effective simple design that would work with many drivers. For those who want more bass output, that general layout leaves plenty of room for more bass drivers.
