If we imagine a life without speakers, it would sound so odd (pun intended). Speakers have helped us in numerous ways by aiding in creating mega sounds, large volume output, and assisting in listening. Modern speakers are one of the most sophisticated ones but this hasn’t been the case always. The different types of speakers in history have been quite complicated to use and operate.
About a Loudspeaker
By definition, loudspeakers can be referred to as electroacoustic transducers which help in converting the different types of audio signals into the relevant and corresponding sound. Loudspeakers are found in almost everything today. Radios, cellphones, amplifiers, car systems, music systems, theaters, cinemas, and many other applications of loudspeakers are present today.
Dynamic speakers are mostly used for providing the most accurate sound quality as the sound source has been amplified with an audio power amplifier before the signal is sent to a speaker. This leads to a reduced level of distortion as well as improves the rhythmic flow of the sound.
The First Speakers
The first speakers date back to 1861 when Johann Reis installed an electric loudspeaker in his telephone. This was the first speaker which could produce clear tones. Prior to that, there was some work on speakers but was unsuccessful because there was a high distortion that made it very difficult to understand the message. Despite the fact that Johann Reis developed the first loudspeaker, history remembers Graham Bell, the inventor of the telephone who patented the first electric loudspeaker.
There were some tweaks compared to the design by Reis as this speaker was capable of reproducing intelligible speech with minimal distortion. Around 1877, Thomas Edison also made some effort towards the development of speakers as he used a system that consisted of compressed air and had an amplifying mechanism allowing for cylinder phonographs. However, Edison realized that the metal horn by the membrane was a much better option.
Compressed Air Loudspeakers
As time passed, there were other developments in speakers and Horace Short finally patented a design in 1898 for a loudspeaker. The unique thing was that it was driven by compressed air which allowed the sound to be more clear. The patent was later on sold to Charles Parsons. This was one of the major developments towards the speakers as many companies started taking an active part in producing record players using compressed-air loudspeakers.
Although these speakers were clearer than the ones that were made in the past, they were still not entirely perfect which is why the industry continued on further development. Compressed-air speakers were also lacking in the way that they could not produce low volume sounds and only the large volume sounds were possible. For example, train horns, public addressing, and space equipment were important applications of the compressed-air speakers.
The Era of Dynamic Speakers
Speakers that we use today are mostly dynamic speakers. These were first invented by Edward Kellogg and Chester Rice in 1925. The two applied for the patents of the design and got it in 1929. The mechanism of a dynamic speaker was different as there was an alternating electrical audio signal applied to a voice coil. A coil of wire is suspended between the gaps in a permanent magnet while this coil is then forced to move back and forth due to the law of induction. As a result, it caused a diaphragm to move back and forth creating sound waves.
This was a major milestone that was achieved during the 1930s. However, the first commercial fixed-magnet loudspeakers were very large and consisted of heavy iron magnets which were impractical for day to day use of a common person. The application of these speakers for individual requirements was very limited and they were mostly used for large processions or political leader movements.
Find out more about the history of earphones here – The Evolution of Headphones.
Shearer Horn System for Theatres
During the 1930s, many companies had been involved in the production and sales of loudspeakers. Manufacturers began to test the loudspeakers by bringing different tweaks to the design and mechanism. Two and three bandpasses were combined so that the frequency response and the sound pressure could be adjusted. In 1937, the loudspeakers were first made available for the theaters. This was known as the Shearer Horn System for Theatres.
This system specifically used 15’ low-frequency drivers with a crossover network set of 375 Hz. The single horn with two compression drivers aided it in providing high-frequency sounds. Many of the top actors and theatre artists including Douglas Shearer and John Kenneth played their roles with this system. The system was slightly improved and in 1939, the New York World Fair featured a bigger speaker with 27’ low-frequency drivers.
In 1943, the 604 was developed by Altec Lansing. This offered better clarity at high output levels such as theatres and cinemas making them more useful. The Academy of Motion Picture and Arts then started to use these kinds of speakers and were made as a standard in 1955. Moreover, Edgar Villchur had the acoustic suspension principle design made for the loudspeakers in 1955.
With his improvements, the design offered better control over the bass response of the speakers. It was important because stereo recordings could not control a lot of bass and make high definition songs while with this design, the process got easier. Edgar later created an Acoustic Research company to market speaker systems. It was soon evident that the speaker systems could be used for small-scale individual customers as well.
The earlier speakers were not entirely power controlled while the ones designed in 1964 were the first powered loudspeakers. This meant that any pair of monitor speakers could be converted into self-power with a second speaker that will be generating power from the first one. Studio monitors with an active crossover that had a specific three-way hybrid design along with two amplifier channels were introduced in 1967 by Klein Hummel.
Later developments followed in 1980 when Meyer Sound Laboratories invented the active 2-way system which had active electronics mounted outside along with Meyer’s active crossover. The benefit was that this could be connected to third-party customer-specified amplifiers as well. In 1990, Meyer also produced the first powered speaker.
Although nobody wanted Meyer speakers back then, today they are one of the most used ones. Coming with built-in amplifiers, they can be used in a bigger environment such as concerts, large processions, events, and even DJ Parties. Home cinema audio systems also use powered speakers.
Speakers which are highly powered also use a driver called Tweeter. The tweeter produces the highest frequencies in a speaker from 2KHz to 20KHz. The word Tweeter has come from bird sounds that are quite high pitched. Tweeters are found in home stereo systems and compression drivers to have professional sound reinforcement. Ribbon Tweeters have become increasingly popular over the past many years.
On the other hand, woofers are also used which produce low-frequency sounds. They are the exact opposite of a tweeter. The woofers can produce sounds between 50 Hz up to 1000 Hz and are an important part of many modern-day speakers. They have gotten their name from the low-pitched sound of a dog barking (woof).
The first wireless bluetooth speakers were introduced in 1994 which worked on the mechanism of radio signals rather than the Bluetooth ones which we find nowadays. The operation of this speaker was an easy one with a transmitter sending radio signals to a receiver that was in a loudspeaker. The board amplifier powers up the woofer. The broadcast of radio signals allowed the speaker to emit sound.
The concept of the first wireless speakers was not much successful since the radio signals delivered the sound at a slower speed. Possible issues with this speaker included a lower signal strength or blocked antennae. However, with Bluetooth wireless speakers coming in, this problem was resolved. The Bluetooth wireless speakers are one of the most used items today. They have been the invention of the 21st century making the concept of sounds and speakers more active and realistic.
These wireless speakers do not work entirely without power. Either they use cells and batteries for operations or they have to be charged for a certain while prior to their usage. Only the wire that has been connected to the amplifier is eliminated for the case of a wireless speaker. A key advantage of the wireless speakers is that they are designed in a way that they are quite lightweight.
Suggested Reading – A Quick Guide to MP3 – What it Is and How it Changed the Music Industry.
Over the years, there has been some serious advancement to speaker technology. From the ones that had extraordinary distortion and very big size, we have come across and the speakers today can be easily held in hand. Mostly, powered speakers and wireless speakers are used today for individual needs. If you are planning to buy a speaker, it would be our recommendation to go for the wireless ones since they are the latest ones and can be used anywhere.