One of my bookmarks for sure, good description and well written imo.
Hey, Mfusick. Just wait till you hear a set of SEOS designs, they're awesome. Build a pair and then you can decide how far you want to take it. I love mine!
Anyway, linwitz's definition of diffraction is simple: "diffraction is about the transition between an acoustic wave propagating from one space first into another space of different volume."http://www.linkwitzlab.com/faq.htm#Q8
A simulation will show a full 6db loss at the given frequency when it travels across the edge and sides, but it'll change when we're in 4pi space. Most of these SEOS designs' xo's are between 1200Hz-1500Hz and would occur at a shorter wavelength hence the 14.5-17.25" baffles. If there was any compensation added, a wall might cause an unwanted rise in response right around crossover frequency. Check out Bagby's Diffraction and Boundary simulator to see this happen in 2pi. If had to develop a bsc circuit, though, I would start at 2db and work up in values (parallel resistor and inductor in series). Measure-repeat. There are many variables depending on the crossover order, but ultimately this has to be attained through driver's frequency response in the final system.
So, ya, you'd probably need to redesign if doing a baffle wall.
Build a pair and stick them behind an acoustic transparent screen...