Loudspeakers convert electrical signals into air vibrations which the human ear perceives as sound. The classic loudspeaker design is one or more radiating heads in an acoustic enclosure. The sound source is the head itself. The design or enclosure provides only the quality and expressiveness of the sound at the desired frequency range.
The closest technical analogue to loudspeakers is headphones or microphone speakers. But there is one major difference between headphones and loudspeakers: headphones are not designed to transmit sound waves into an open space, while this is the main purpose of loudspeakers.
How Loudspeakers Work
Technically speaking, a loudspeaker is an electro-acoustic transducer. What does that mean? Its operating principle is based on the interaction of a conductor with a magnetic field. When current is applied, the poles of the magnet form a field. In it there is a conductor (most often a coil), on which the electrodynamics force acts.
It tends to push the conductor out of the magnetic field, creating oscillations. The coil is rigidly connected to the cone, which also begins to oscillate, resulting in sound waves.
The coil is a frame wrapped with aluminum or copper wire. The number of layers of wire is even, because the coil leads must be on one side, and this requires 2 or 4 layers of winding. The frame with the winding is bonded with varnish. The leads are glued securely to the cone and to the frame.
Another important element of a loudspeaker is the centering washer. It sets the correct position of the voice coil in the magnetic field. It is stiffer than a conductor, so it maintains the fundamental resonance of the moving system of the loudspeaker.
Finally, the design implies the presence of a cone.
This is the radiating element that determines the electro-acoustic performance of the device. It is tapered because it causes parts of the diaphragm to oscillate at different pitches and frequencies. But round and oval cones are also used.
These elements are molded from paper pulp and are between 0.1 mm and 0.4 mm thick. The lower the weight of the cone and the stiffer the material, the better the loudspeaker reproduces high frequencies.
Types of Loudspeakers
This type of acoustic equipment can also be called another way: loudspeaker. Loudspeakers are an indispensable part of acoustic systems, public address and sound. They are used by musicians and sound directors during concerts, theatrical performances, and film screenings. The main task of a loudspeaker is to convert electrical signals into acoustic vibrations.
There are different kinds of loudspeakers available for sale. The most common classification is based on the way they sound. But other characteristics are also important:
- Operating principle: electrostatic, plasma, piezoceramic, electrodynamics.
- Frequency: broadband, low-, medium- and high-frequency.
- Applicability: for receivers, loudspeakers, recording studios, etc.
However, when buying, the first criterion of choice is the sound. The most popular option is an electrodynamics loudspeaker. Its design is similar to a microphone: a magnet creates a field, in it there is a coil, which oscillates from electrical impulses, forming sound waves.
They are formed by the pressure on the diaphragm of the cone. Such a speaker is easy to use, inexpensive and maintains high sound quality.
An electrostatic loudspeaker works on a similar principle, but it is based on the oscillation of two membranes, with high voltage electrical energy acting between them. Electromagnetic models use a magnetized cone and a powerful electromagnet, which create acoustic waves using voltage pulses.
Piezoelectric models are arranged differently. They generate acoustic waves of the desired frequency by oscillating a diaphragm, which is produced by an electric field. Loudspeakers-ionophones do not need any diaphragms at all because they use electrical discharges for sound vibrations.
This is the main classification of loudspeakers, but they can also be divided into types according to other characteristics:
- The method of connection to the broadcast network: low impedance, which are connected directly to the output terminal of the amplifier, and transformer, which are connected to the broadcast output with a transformer.
- Signal conversion principle: coil (electrodynamics), electret (electrostatic), fixed-coil (electromagnetic), tape models (piezoelectric principle of operation).
- Typical applications: indoor, all-weather models for outdoor use and loudspeakers in explosion-proof housings.
- By design: flush-mounted, surface-mounted, case-mounted.
Indoor units are not very sturdy. All-weather models, on the contrary, are protected not only from mechanical damage, but also from the penetration of moisture. Explosion-proof housing is designed for rooms where aggressive and explosive substances are stored. You may find this information useful if you want to buy a PA Speaker https://www.walkermcguire.com.
History of The Speaker
The first electronic device that we today call a loudspeaker was mounted to his telephone by Johann Philipp Reis. The device, strangely enough, failed to gain fame and recognition among mankind for the next 37 years.
In 1898, the idea was developed by Horace Short, who created the Auxetophone. It was first used in public in 1900 atop the Eiffel Tower. A phonographic recording of an opera aria resounded over all of Paris and the joyously flowing Seine, stealing the hearts of mankind forever. Work began on further technological developments.
Electricity
In 1906, the first electric speaker is created, invented by Miller Reese Hutchinson and Kelly Turner. In 1912, the Olympic Theatre in Chicago had the first two water-cooled speaker transmitters, an inductor and ten speakers.
The watershed moment
It is 1924 and C.W. Rice and E.W. Kellog of General Electric have developed the magneto-electric loudspeaker. It consisted of a magnet, a moving coil and a diaphragm. It is the “great-grandfather” of our current loudspeakers. In 1958 the first loudspeakers were created, enclosed in a neat casing.
Present
And here they are: JBL loudspeakers. As you can read, generations have worked for their existence. Exceptional, clever, handy and unique. You’ll be amazed by their appearance and the quality of their music. Available in a wide range of colors. Dedicated to women, men and young people, therefore produced in various shapes and colors.
Back in 1958, when the first speaker in a cabinet was created, did anyone expect such an explosion of technology? JBL has created little masterpieces that fit in pants pockets, work wirelessly, and can be taken literally anywhere.
Technical Specifications
Speakers are available in a very wide price range. We can safely say that their purchase is affordable for every pocket. The equipment impresses with the quality of sound. It connects with devices via Bluetooth, has a rechargeable battery and charging time is about 2.5 hours. It works about 10-12 hours on a full battery. Weight depends individually on the model, but more or less devices weigh about 500g. The most advanced models weigh about 2400 g.
It would be difficult to function in today’s world without speakers. We would not be able to listen to the radio or television. Talk on the phone. Watch movies in the cinema or on a smartphone. Organizing concerts would be much more difficult. The loudspeaker is an invention that gave birth to a new technological era. Without it many of today’s electronic devices would not exist.
PA Systems
PA systems make it possible to distribute a diverse audio signal to all loudspeaker zones or simply to switch signals (e.g. between background music and microphone announcements) easily over the entire area. You can find more here.
PA systems are used for all types of spoken word broadcasts, for speakers, for DJs playing pre-recorded music, as well as for music and background announcements in stores, shopping malls, supermarkets, schools, offices, sports facilities, restaurants, office buildings, factories, hospitals, airports and stations, backyards, and many more.
We hope this article was helpful to you!