The Loudspeaker: A Brief History

The speaker is the closest to its original form of all the components in an audio system. But they’ve come a long way -- on the inside.

1874: Ernst W. Siemens applies for a U.S. patent for what he describes as a “dynamic,” or moving-coil, transducer. Siemens takes a circular coil of wire and supports it so it moves axially in a magnetic field. His patent is applied for as a “magneto-electric apparatus.” Oddly, his design isn’t used for anything audible.

1876: Alexander Graham Bell patents the telephone. Siemens works on a nonmagnetic parchment diaphragm to act as the audible radiator for his moving-coil transducer and patents his technology one year later. It’s mostly used in phonograph players in the acoustic era. His cone is attached to flaring “morning glory”-shaped horns.

1911: Edwin S. Pridham and Peter L. Jensen invent the Magnavox -- the world’s first PA system. Wilson uses this moving-coil loudspeaker in a time when most speakers are cone designs and their frequency range is limited.

1931: Bell Labs develops the first fidelity speaker. This two-way loudspeaker (called “divided range”) uses a small horn to produce frequencies in the range of 3K to 13K hertz. The 12-inch dynamic cone radiator offers a frequency range from 5K to 10K hertz.

1932: RCA releases its own dual-range speaker for theaters. It incorporates three 6-inch cone diaphragms with aluminum voice coils aimed in multiple directions for a frequency response of 125K to 8K hertz, and 10-foot-long horns capable of reproducing 40 to 125 hertz. Hence, the era of the multi-cell horn commences.

1945: Altec Lansing Corp. puts its two-way “Voice of the Theater” speaker system on the market. It offers improved horns and magnetic drivers.

1974: Universal Pictures releases Sensurround sound for its new picture, Earthquake. It enhances low-frequency enough that during the film, the whole theaters rumble with the earthquake and aftershocks. This is done with four large, low-frequency horns installed behind each screen. Individual horns measure 8 feet long, 4 feet wide and four feet tall. One-thousand-watt amplifiers in the back corners of the theaters power two additional horns.

1982: George Lucas and his THX sound system shoot moviegoers into a new galaxy of sound with the release of Return of the Jedi. Here, a combination of speakers, crossover networks and a high standard of audio equipment and performance standards set the next level of quality.

A Few More Fun Facts

Sound reinforcement was born of a need to train World War I soldiers to use rifles. The existing method was to train one soldier at a time -- a slow process. Because the motion-picture industry was just taking off, it was determined that it would be faster to use a movie as a training tool. Thus, Army training films were born.

In the beginning, loudspeakers were a cottage industry. By evenings, families made the parts (voice coils, cones, etc.) and then assembled them the next day. Most of these companies/families experienced tough times during the Depression.

Amazing improvements have been made over the last few years as inventors apply what they’ve learned about sound-reinforcement technology. Each time I see something new, I can’t help but think of how far we’ve come.

Floyd Paulsen is a full-time sound technician at the Indiana Convention Center in Indianapolis and has toured with numerous Christian artists. Paulsen has produced three mixing console training resources: “Mixing Console ABCs” (video), “Feedback Training” (CD) and The Sunday Soundman Basic Training (manual). E-mail Paulsen at sundaysoundman@netdirect.net. Paulsen is also the author of Behind the Grand Drape: 25 Years of Celebrity Backstage Adventures. For more information, log on to www.behindthegranddrape.com.