Lowther Voigt TPA Corner Horn
The TPA is one of my favorite speakers yet I have never listened to one. This preference is entirely based on asthetics. It could sound like a bose wave radio for all I know. Ok I doubt it. I know little of its history but it seems to have been produced from 1951-1960's. There is some info available at the Lowther Voigt museum web site. http://www.lowthervoigtmuseum.org.uk/index.html
Courtesy of Hi-Fi Lit
The legendary Lowther driver in a back loaded horn.
Here are some pics from of the TPA at the Klipch Audio History Museum in Hope, AR. This is one of the best examples I've seen.
The tag on the back of the TPA.
If you have additional information on the Lowther TPA please post comment.