Straight horn loudspeaker, 1921.
© Science Museum / Science & Society Picture Library
This type of loudspeaker would have been used in the home, to amplify radio transmisions. 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. Made by S G Brown.