These are the plans for a pair of Voigt pipes built by Herbert Jeschke, taken from the single driver website athttp://www.melhuish.org/audio/DIYTQ4.html The Voigt Pipe is a Tapered Quarter Wave Pipe enclosure, which is a very old design and not very popular today becasue of its size (if built full length like this one) or the complexity of the cabinet if built as a folded horn. But it's one of the easiest speakers to build if built full length like this.

These are the plans for a pair of Voigt pipes built by Herbert Jeschke, taken from the single driver website athttp://www.melhuish.org/audio/DIYTQ4.html The Voigt Pipe is a Tapered Quarter Wave Pipe enclosure, which is a very old design and not very popular today becasue of its size (if built full length like this one) or the complexity of the cabinet if built as a folded horn. But it's one of the easiest speakers to build if built full length like this.