Since there are a handful that are making their π Speakers tall and thin, and since we've begin to discuss transmission line and standing wave behavior, I felt that it might be a good time to mention the following link.Acoustic Filters, Waveguides and Transmission Lines, by Daniel Russell of the Science and Mathematics department of GMI Institute.
This paper describes acoustic filter chambers, low-pass, high-pass and band-stop. The characteristics of each type of chamber are discussed, as well as the properties required and the specific methods of solutions for each.
It's a simple discussion about acoustic chambers and ducts, and provides formulas describing their properties. Acoustic chambers that provide high-pass, low-pass and band-stop (notch filter) properties are shown. The paper is written as a laboratory exercise for students of acoustics.
Follow Ups: