Link to Voigt pipe archives, a digest of valuable resources, the original web pages already unavailable:

https://sites.google.com/site/radioandelectronics/voight-speaker-archive

Within this archive, look for "THE VOIGT PIPE The Joke!" article. It was written by Derek Walton (credits missing in the digest). His report and cabinet dimensions, ratios, materials choices, amplifier matching was the inspiration to build my Fostex FE204 Voigt pipe. I have heard a very wide array of pipes, transmission lines, and designed & built a bucket load of them, yet this cabinet has proved to be far, far superior to any else. More on this later, will share my cabinet plans. (Have to re-measure, my original plans lost in hard-drive crashes.) -- 7/28/2022