“Tefag” is a marketing abbreviation of the name of the Telephon-Fabrik Berliner AG group, founded in Hanover in 1898 by Joseph Berliner – an entrepreneur of Jewish origin, brother of Emil Berliner (inventor of the gramophone and gramophone record). From 1927, the headquarters of the company was in Berlin. Due to the Great Depression and the economic, social, and political disturbances in Germany at the break of the 1920s and 1930s, the ownership structure of the company underwent several transformations. Tefag primarily manufactured telephones, cables, and other telecommunication devices, while the production of loudspeakers was a side branch of their operations.
The 1920s are the period in which the first radio receivers appeared in shops, and radio itself, as a new means of communication, gained popularity. The first devices were, however, designed in a way that listening to the radio involved the necessity of earphones. Solutions were sought that would ensure broader reception of the broadcast programmes. To that end, attachable horn speakers were designed. The first models appeared in Europe around 1922 when (for lack of other sockets) they were connected to earphone outputs.
Horn speakers consisted of two components. The sound source was an induction/magnetic converter system, as used in telephone receivers. The device’s system allowed sound volume to be adjusted using a screw with a permanent connection to the coils and magnet. Turning the knob allowed the magnet to be brought closer to the membrane, and thus for its vibration to be adjusted. An acoustic horn, made of aluminium or, less often, wood, was installed on the housing of the transducer. The horn had a shape similar to that of a cone or pyramid with a fan-like lip on the edges at the wider end, which was supposed to increase voice amplification. An expressive description of the strengths and weaknesses can be found on pages of Katalog Działu Radjotechnicznego, which reads: “essentially, horn speakers are larger earphones with a horn making the voice fuller and more expressive. The speakers provide a so-called objective reception, which means that the reception is available for the majority of listeners. Unfortunately, their disadvantage is that they produce a voice similar to that of a gramophone, with a trace of metallic undertones”.
The Cornet 1278 horn speaker (Trichterlautsprecher, or “funnel speaker”) was included in the Tefag product range in the 1928/1929 season, and it cost 28 reichsmarks. The range also included horn speakers with different profiles, such as the Goliath 1275 and the Fanfare 1279, as well as conical speakers in which the aluminium horn was replaced with a paper membrane – the Conus 1257, Ultra-Conus 1254, and Secundus 1253.

Author: Filip Wróblewski