Phonogen specifications

Category : Manufacturer

Already during his physics studies at the University of Stuttgart, Norbert Schäfer, born in 1942, had begun to build loudspeaker cabinets. From about 1968, the student worked on folded horn constructions, which he initially realized in wood, which, however, tended to resonate in different ways at different points of the horn. In addition, the type of processing, with smooth surfaces and sharp angles, ensured that standing waves could form again and again, which led to sound distortion. The solution seemed to offer the material concrete. On the one hand, its strength should prevent the housing from resonating, on the other hand, it could be cast. This form of processing made it possible to dispense with flat surfaces and said sharp angles as far as possible. Since the professional production of mold and casting by a special company was not financially feasible for a student, Norbert Schäfer developed the mold and the process himself within two years of continuous tests, in addition to his studies. in 1975, the first bass horn made of concrete and plastic, called "Phonogen ", was made possible by the specially founded Expophone KG in Beuron-Hausen / Ts. be presented. The design and production were by Norbert Schäfer, the external design of the box was realized by the designer Holger Scheel. In addition to its production technology, another special feature of this exponential horn was its drive: the membrane was divided into two areas with the help of a glued-on rubber lip, one of which was supposed to reproduce the frequency range between 18 and 250 Hz, and the other the one from 250 to 600 Hz. For the complete full-range box, the horn was supplemented by a conventional midrange driver and a rotatably mounted electrostatic. The Phonogen I boxes now offered by Phonogen Norbert Schäfer KG in Beuron were supplemented in 1978 with an active version Phonogen 1a. On the initiative of the trade journal AUDIO, a collaboration with Friedrich Müller and Wolfgang Backes then took place in 1979, from which the reference was created. For the 1980 model year, Phonogen Schäfer KG, now based in Epfendorf-Talhausen, presented two new loudspeaker cabinets, the Phonogen Live and Concert, which followed a completely different constructive concept than the bass horns with which Phonogen had become known. At the same time, Norbert Schäfer, under Günther Seitz, was employed in the development of Canton . From about 1982, Norbert Schäfer began with large diaphragm tests and thus developed a third design principle for clean bass reproduction, which culminated in the development of the "Trans" series in the second half of the eighties. With the help of an investor, Phonogen Lautsprechersysteme GmbH (Kirchhalde 19, Großbettlingen) was now able to realize the production of Phonogen Transfer. The AUDIO reported, on the occasion of a test report (12/87), a larger model 'Transline' had already been announced. Despite the positive response, Dr. Hans-Joachim Rebmann, owner of Phonogen GmbH, sold his shares in the company to the Munich-based ATL Elektro Akustik GmbH, which also engaged Norbert Schäfer as a freelance developer. In the summer of 1989, a second generation of the Transfer appeared there, and also the smaller Translife and the larger Transart; shortly after, a top-of-the-range model Transmaster was added. The history of ATL and thus also that of Phonogen ended with a comparison in 1994. Parallel to his work for ATL , Norbert Schäfer had launched a new generation of speakers on the market in 1992, with the Designakustik Schäfer in Oberkässach, and, together with the engineer Joachim Zürn, led the Trans series, with Translife GmbH in Schöntal, into a third generation from 1999. In the meantime, Norbert Schäfer has retired from the UN and is currently (as of October 2013) devoting himself to basic research on wave theory.