Loudspeakers utilize the fact that if you run a varying electrical current through a coil situated in a magnetic field, the coil will move in response to the current. This idea was introduced in 1874 by Ernst Siemens, a prolific German inventor. (He also built the world’s first electrically powered elevator in 1880.) Today, Siemens AG is one of the largest electronics companies in the world.
When Alexander Graham Bell patented the telephone in 1876, he used Siemen’s concept to create audible frequencies in the earpiece. From that point on, sound-reproduction devices gradually increased in quality and power, until Chester Rice and Edward Kellogg at General Electric published a paper in 1925 establishing basic principles that are still used in loudspeaker design today.
As sound amplifiers became more powerful, speaker efficiency became less important compared with quality reproduction and low manufacturing costs. Today’s loudspeakers convert only about 1% of electrical energy into acoustical energy.
When Alexander Graham Bell patented the telephone in 1876, he used Siemen’s concept to create audible frequencies in the earpiece. From that point on, sound-reproduction devices gradually increased in quality and power, until Chester Rice and Edward Kellogg at General Electric published a paper in 1925 establishing basic principles that are still used in loudspeaker design today.
As sound amplifiers became more powerful, speaker efficiency became less important compared with quality reproduction and low manufacturing costs. Today’s loudspeakers convert only about 1% of electrical energy into acoustical energy.
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