A few years ago, with much help from a mathematical friend, I wrote up theory and construction plans for several RPG-style diffusors, which are based on the work of a mathematician named Manfred Schroeder. I have it as an emailable 8 page MS Word document, and could email pics as well. So if anyone's interested, email me at
[email protected] and I'll send it on. The most theoretically interesting to me is the two-dimensional Primitive Root Diffusor (PRD), RPG's Skyline is one. The theory turns on a bit of exotica known as the Chinese Remainder Theorem, which I'd heard of years ago as being used in some proofs of Godel's Theorem in mathematical logic. This is whole number mathematics, and how it connects with acoustic theory is completely opaque to me--but it evidently does. My PRD's are at least as good as RPG's Skylines,if I say so myself. (I have both in a Quad ESL 63 system.) They do require a table saw or the like to build.
