Beyerdynamic DT48, 1937 German audio equipment manufacturer Beyerdynamic, which started out creating loudspeakers for cinemas, developed the first pair of dynamic headphones the DT48. They used a coil of wire attached to the back of a speaker cone through which the current of the audio signal was carried, causing it to move in a fixed magnetic field to move the air and create sound.Dynamic drivers are still the most popular type used in headphones and speakers today, and the DT48 were still in production in one form or another until 2012.

Photograph: BeyerDynanic