The speaker, or loudspeaker, have been a staple when it comes to sound systems. Speakers are found in home entertainment systems, computers, and even integrated into gadgets like phones. They are used in many applications, like sporting events, parties, gatherings, seminars and the like. But have you ever wondered how the idea of a loudspeaker came to life
The first loudspeakers
Modern electric loudspeakers had their origins in radio and telephone technology. The first simple type of electronic loudspeaker was developed by Johann Philipp Reis in 1861. Reis was a teacher at Friedrichsdorf, Germany and he was a self-taught inventor. He installed it on his telephone. It was crudely able to reproduce clear tones, but it can also reproduce muffled speech after a few revisions.
In 1876, Alexander Graham Bell, the inventor of the telephone, tried to produce a speaker based on Reis’ work. This time, there wasn’t enough knowledge yet about physics and material engineering to successfully invent an electrodynamic loudspeaker. The need to amplify sounds did help spur the development of amplifiers.
The idea of an electromagnetic coil-driven speaker was introduced in 1877 by Werner Von Siemens, the founder of the electrical and telecommunications company Siemens. Siemens used to input signals of DC transients and telegraphic signals. This wasn’t a successful speaker, but due to his experiments, he theorized that amplification could be eventually done.
At the same time, Thomas Edison and Nikola Tesla were experimenting with similar devices. Edison has issued a British patent for a system using compressed air for an amplifying mechanism for his phonographs. However, he settled for the familiar metal horn driven by a membrane attached to a stylus.
Inventors relied on horns for amplifications back then. Thomas Edison, Magnavox and the Victor Talking Machine Company (maker of the Victrola wind-up phonographs) all developed advanced and well-performing horns. The problem is, their horns don’t amplify the sound very much.
In 1898, Horace Short gained a patent for a loudspeaker that is driven by compressed air. He sold the rights to Charles Parsons.
Various inventors and companies played with the idea of the electrodynamic loudspeaker. Companies like Pathé and the Victor Talking Machine Company produced record players using compressed air speakers, but those are significantly limited by poor, distorted sounds.
Moving coil loudspeakers
The first experimental moving coil loudspeaker was developed by Oliver Lodge in 1898. Later, Peter L. Jensen and Edwin Pridham manufactured practical moving coil loudspeakers in 1915. Like the previous loudspeakers, they used horns to amplify the sound produced by a small diaphragm. Jensen and Pridham were denied patents, so they changed their target market to radios and public address systems. They developed their own company called Magnavox, and it became a success.
The moving coil principle was patented in 1924 by Chester W. Rice of General Electric and Edward W. Kellog of AT&T. The two were able to adjust the properties of coils until they lowered the frequency at which the cone’s radiation impedance became uniform, thus replicating noise. Previous attempts to make the loudspeaker produced unacceptable muffled sounds, but Rice and Kellogg solved the problems that led to nice, crisp audio. Their prototype had a more diverse dynamic range in frequencies, making it better than the horn. It can also increase in loudness. After several years, they perfected the product and called it the Radiola Loudspeaker #104. It was sold in 1926 for $250 and was produced under the Radio Corporation of America (RCA).
The first real loudspeakers
The electric devices used to create sound in telephone and in radio earphones were called receivers or reproducers. During the 1880s to 1890s, inventors would occasionally think up of ways to use the telephone for a larger audience. Some simply attached a large horn to a telephone receiver to make a “loudspeaking telephone.” This was where the term loudspeaker originated.
When Bell Labs introduced the first electronic vacuum tube amplifier in 1916, the true loudspeaker became possible. This kind of speaker was fine for public address systems offered in 1921, but the sound quality wasn’t good enough for motion pictures just yet.
In 1924, the first commercial electric loudspeaker was introduced. It used an electromagnet to drive a large paper cone that reproduced the original sound, as it vibrated under the influence of the amplified signal. This was based on some versions of the early telephones from the Siemens Company during the 1880s.
Meanwhile, radio created another branch of loudspeaker technology. In 1924, Brunswick Balke Collender Company introduced the first all-electric home phonograph, in cooperation with RCA, Westinghouse, and General Electric. This was the first home phonograph that was called a “dynamic” loudspeaker, which was similar to the kind still used today.
Around 1924, Walter H. Schottky invented the first ribbon loudspeaker together with Dr. Erwin Gerlach. These loudspeakers used diodes.
Later on in the 1930s, ribbon loudspeakers began to combine drivers in order to make amplification better. In 1937, James Bullough Lansing, Douglas Shearer, and John Kenneth Hilliard invented the “Shearer Horn System for Theaters.” This system was introduced to the film industry by Metro-Goldwyn Mayer. It used 15” low-frequency drivers, a crossover network and a single multi-cellular horn with two compression drivers that provide high frequency.
In 1939, a very large public address system was mounted on a tower at Flushing Meadows during the New York World’s Fair. It was designed by Rudy Bozak, who worked as a chief engineer for Cinaudagraph.
In 1943, Altec Lansing introduced the 604, which was the famous Duplex driver that dramatically improved sound quality and performance. Altec’s “Voice of the Theatre” loudspeaker system hit the market in 1945, and it offered better clarity and coherence at high volumes, which was important in movie theaters. It was immediately tested by the Academy of Motion Picture Arts and Sciences and made it film house industry standard in 1955. Until now, this loudspeaker design is still used.
The principle of acoustic suspension for loudspeakers was first developed by Edgar Villchur in 1954. This allowed better bass response than previous drivers mounted in smaller cabinets. This technology was important during the transition to stereo recording and production. Villchur and Henry Kloss formed the Acoustic Research Company to manufacture and sell speaker systems with acoustic suspension. Today you have many choices of the best center channel speakers for home theater available that can provide you great sound quality and bass.
Subsequently, this led to continuous developments in speaker enclosure design for audio quality improvements. The most notable developments in modern dynamic drivers are the improved cone materials, improved permanent magnet materials, the addition of higher-temperature adhesives, improved measurement techniques, and computer-generated designs.
Related Post: History of the iRobot Robot Vacuum Family