Five loudspeakers, 1920s.
© Science Museum / Science & Society Picture Library
Before modern moving-coil loudspeakers, most people listened to the radio on headphones. A speaker, if you had one, would probably have fixed coils driving an iron reed attached to a small diaphragm. The exception here is the Frenophone (left), which incorporates a unique clockwork amplifier. The others (left to right) are: the Serling Primax, with pleated diaphragm; the Crystavox, which drove its reed through an amplifier formed by coupling a telephone receiver to a microphone; a straight horn typespeakers by S G Brown and a speaker made by Amplion.