Acoustic Transmission Line - Commercial and Amateur Loudspeaker Designs

Commercial and Amateur Loudspeaker Designs

Commercially successful folded transmission lines have been produced, although some have suffered from reflections at the bends.

One example of a transmission line enclosure design was by Vivan Capel called the "Kapellmeister" published in Electronics Today International, circa 1975. This was a double-folded line which placed the first, third, and fifth harmonics of the line's resonant frequency at the bends and the exit, where they would cause least movement. The Kapellmeister suffered from poor deep bass, and was designed around a low power driver. Capel, like Bailey, believed that the pipe's cross-sectional area needed to be equal the driver's cone area.

There are not many companies producing commercial transmission line loudspeakers as the technology is difficult to get right. One company that does successfully manufacture them is UK based PMC or the Professional Monitor Company. Its hi-fi and studio monitor designs use a development of the transmission line that they call the Advanced Transmission Line.