The first form of loudspeaker came about when telephone systems were developed in the late 19th century. But it was in 1912 that the loudspeakers really became practical – in part due to the electronic amplification by a vacuum tube. In the 1920s, they were used in radio, phonographs, public address systems and theater sound systems for spoken films.
What is a speaker?
By definition, a loudspeaker is an electro-acoustic transducer that converts an electrical audio signal into a corresponding sound. The most common type of speaker today is the dynamic speaker. It was invented in 1925 by Edward W. Kellogg and Chester W. Rice. The dynamic speaker operates on the same basic principle as a dynamic microphone, except in the reverse direction of producing sound from an electrical signal.
Smaller speakers are found in everything from radios and televisions to portable audio players, computers and electronic musical instruments. Larger speaker systems are used for music, sound reinforcement in theaters and concerts and in public address systems.
First Loudspeakers Installed on Phones
Johann Philipp Reis installed an electric speaker on his phone in 1861 and was able to reproduce light tones and reproduce muffled speech. Alexander Graham Bell patented his first electric speaker capable of reproducing intelligible speech in 1876 as part of his phone. Ernst Siemens improved the following year.
In 1898, Horace Short won a patent for a loudspeaker powered by compressed air. Some companies have produced recorders using compressed air speakers, but these projects had poor sound quality and could not reproduce sound at a low volume.
Dynamic speakers become the standard
The first moving coil (dynamic) speakers were made by Peter L. Jensen and Edwin Pridham in 1915 in Napa, California. Like previous speakers, they used horns to amplify the sound produced by a small diaphragm. The problem, however, was that Jensen was unable to obtain a patent. Then, they switched their target market to radio and public address systems and named their product Magnavox. The mobile coil technology commonly used today in loudspeakers was patented in 1924 by Chester W. Rice and Edward W. Kellogg.
In the 1930s, speaker manufacturers were able to increase the frequency response and the sound pressure level. In 1937, the first standard loudspeaker system in the film industry was introduced by Metro-Goldwyn-Mayer. A large two-way public address system was mounted on a tower at Flushing Meadows at the 1939 New York World’s Fair.
Altec Lansing introduced the 604 speaker in 1943 and its “Voice of the Theater” speaker system was sold from 1945 onwards. It offered better consistency and clarity at the high output levels needed for use in cinemas. Film Arts and Sciences Immediately began testing its sound characteristics and they made it the standard of the film industry in 1955.
In 1954, Edgar Villchur created the principle of acoustic suspension for the speaker design in Cambridge, Massachusetts. This design provided a better bass response and was important during the transition to stereo recording and playback. He and his partner, Henry Kloss, formed the company Acoustic Research to manufacture and market speaker systems using this principle.