Loudspeakers: device, principle of operation and scope

Loudspeakers have been around for a very long time. The name of these devices speaks for itself - they are capable of transmitting sounds loudly... In today's article, we will learn about such equipment, as well as in what areas it is used.

The loudspeaker is a special device that is used to play loud sounds. The amplification of the signal emanating from the source in modern units occurs mechanically or using an electroacoustic method. In security and fire-fighting devices of a combined subspecies, loudspeakers are usually used for the purpose of warning equipment and do an excellent job with their duties. Due to the use of these technical devices in combination with powerful light indicators, the risks during the evacuation of personnel or visitors to institutions are significantly reduced.

High-quality loudspeaker models produced by modern manufacturers have ceased to be used only as warning devices in case of fire.

Alexander Graham Bell patented the first electrodynamic head as one of the constituent parts of the phone. This happened in 1876-1877. And already in 1878 the design was improved Werner von Siemens. In 1881 Nikola Tesla also made a statement about the invention of a device of a similar type, but did not start patenting it. At the same time Thomas Edison obtained a British patent for a system that could use compressed air as the sonic amplification mechanism in early roller phonographs, but ended up installing an ordinary horn made of metal.

In 1898 H. Short patented a loudspeaker device, which was controlled using compressed air... After that, he sold the rights to his development. Charles Parsons.

Some companies, among which were both the Victor Talking Machine Company and Pathe, specialized in the production of turntables, in the design of which there were heads controlled by compressed air. But devices of this type were used to a limited extent, because they could not produce good sound quality. It was impossible to achieve persistent sound at low volume. Variations of these systems have been used in sound reinforcement installations and, in rare cases, on an industrial (test equipment) scale.

The current moving coil head design was developed by Oliver Lodge in 1898. The principle of this part was patented in 1924 by Chester W. Rice and Edward W. Kellogg.

The first gas engines with electromagnets were bulky in size.... High power permanent magnets were difficult to obtain because they were expensive. The winding of the electromagnet, which is called the field winding, is magnetized due to the current that goes along a different winding of the head.

The quality level of acoustic recording systems before the 1950s was not the highest. The design of the body of the devices is being updated to this day. More attention began to be paid to the materials used in the production of equipment, which had a beneficial effect on the direct quality of sound reproduction.

Loudspeakers are useful devices that play a significant role in their field of application. Large or small production workshops, stage-by-stage production, where uninterrupted communication of the links of the entire process is necessary, cannot do without such equipment. Loud-speaking communication makes it possible to convey to the personnel the necessary changes regarding technological processes, breaking news that appeared during the working day. When this sound equipment is present in an industrial space, workers can be aware of all important matters and changes without leaving their workplaces.

With the help of loudspeakers, dispatch services can control and accumulate units for more coherent and productive work using voice commands.

Loudspeakers are often used by people for additional income. One of the responsibilities of promoters today is to make interesting presentations and communicate with their target audience. To reach as many people as possible, you will need to demonstrate not only well-coordinated and beautiful, but also loud enough speech. In order not to spoil your own vocal cords by constant screaming, it is advisable to use a manual loudspeaker model. Belt-type models have been used by promoters for a long time, since they are comfortable and compact, they do not need to be constantly carried in their hands.

In crowded places and on beaches, outdoor loudspeakers are always required. Keeping the level of security under control in such conditions, the security service or the administration of the square have the right to make this or that statement, or to warn people about the danger.

A modern loudspeaker circuit consists of several basic parts. Arranged equipment from the following basic systems:

• EL - electrical subsystems;
• EM - electromechanical subsystems;
• MA - mechanical-acoustic system;
• AK - acoustic subsystem.

The device works based on the interaction of the conductor and the magnetic field... When a magnetic pole current is applied, a field is formed. It contains a conductor (usually a coil), which is acted upon by an electromagnetic force. It will tend to push the conductor out of the magnetic field, forming vibrations. The coil is rigidly connected to the diffuser piece, which also begins to vibrate. Due to such actions, the necessary sound waves are created.

The coil is a frame that is wrapped with copper or aluminum wire. The number of layers is usually even, since the coil leads must be on one side, and this will require 2 to 4 layers of winding. The frame is fastened with a special varnish. The leads are glued as securely and firmly as possible to both the diffuser and the frame base.

There is another important element in the loudspeaker design - centering washer. This detail sets the desired position of the voice coil, which is in the magnetic field. The washer is stiffer than the conductor, so it is responsible for maintaining the main resonance of the moving system of the device.

The design has diffuser... It is one of the best elements in determining the electroacoustic performance of an equipment. It is characterized by its characteristic conical shape, since at high and medium frequencies the cone zones oscillate with different phases and amplitudes. Oval or round diffusers can also be used.

Modern loudspeaker models are different. They differ in many criteria and parameters. They can be distinguished by the range of reproducible frequencies, direct packaging, form factor and many other characteristics. Let's take a closer look at the various subspecies of this technique and learn more about their features.

Depending on how the sound is emitted, the loudspeakers are divided into the following options.

• Electrodynamic... This is a subspecies of the device in which a lightweight coil acts as a source of mechanical vibrations of the diffuser. It moves in the field of a high-power magnet. Such a unit has gained great popularity and wide distribution.

• Electrostatic. This method of radiation is based on the electrostatic interaction of special thin membranes. There is a high voltage between them.

• Piezoelectric. The specified type of radiation is based on the piezoelectric effect.

• Electromagnetic. This type of horn has in its construction magnetic materials from which the cone is made. It moves under the influence of the magnetic field of an electric magnet.

• Ionophone. Assumes a circuit without a diffuser. Air vibrations are generated by electrical charges.

Based on this criterion, different types of loudspeakers are distinguished. Technique may have digital or analog type of connection. The first option is carried out using special connectors and so-called "tulips". The digital connection method involves the use of an optical cable.

Based on the specific amplifier model, instead of the usual standard connectors for the plug, there can be a clamp for "bare" wires... This connection method cannot be called the most convenient. Ordinary people are skeptical about such a solution, although technically it turns out to be more practical, since there are no unnecessary connections. In the latter, there is always additional resistance, which negatively affects the sound quality.

Based on the main characteristics, modern types of loudspeakers are divided into categories.

• Two-way... These are usually active devices with a wide operating range. They are often used as wall elements, but there are also ceiling subtypes. They are used in fire protection systems and are quite common. They are relatively small in size. Differ in power level.

• Wireless. Today on the market you can find high quality and relatively inexpensive wireless speakers. These are handy portable devices that are often purchased by tour guides, animators or teachers. There are multifunctional specimens with additional options and a microphone.

• Broadband. These types of loudspeakers can boast of good sound quality. These models may differ in frequency range and design.

• Explosion-proof. This horn model (common name - "bell") is often installed in the environment of industrial facilities where there are explosive zones.

Loudspeakers are divided according to their design. Very popular today are relatively inexpensive hand modelspresented in a wide range. These options can be portable. They are usually small in size and weight.

There are also built-in loudspeakers... These are often two-lane options that are installed on walls or ceilings. They are not striking and almost do not attract attention to themselves. Most often, white built-in models are on sale.

A separate category includes pendant loudspeakers. These devices can have a wide variety of shapes and power ratings.Sold separately for indoor and more extreme conditions.

Today's loudspeaker models boast rich functionality. In operation, these technical devices show themselves to be more practical and useful. Consider what modern functional loudspeakers are like.

• Studio control... In other words, it is an acoustic monitor, that is, an acoustic system as a loudspeaker in the appropriate design. Usually these are specimens of low power, but with a smooth frequency response. These devices are used in recording studios to control the balance of musical instruments. The sound of this equipment is perfectly clear and clear, so it is often used for listening and recording almost any genre of music.

• Desktop. These types of loudspeakers are often compact and lightweight. Designed to reproduce voice messages about fire and other emergencies. Often, it is desktop equipment that is used to broadcast special sound signals. Often a microphone is included with this device.

Today's manufacturers are releasing more and more new and high quality devices, supplemented by connectors that are relevant for our time, a feedback system, capacious batteries, convenient carrying straps and many other equipment.

The range of loudspeakers continues to grow relentlessly with new multitasking models that are simple and easy to use. Such sound-reproducing equipment is used today in many areas, so the demand for it is not falling.

If you decide to purchase a quality loudspeaker, there are a number of basic criteria you should consider.

1. The first thing you will need to do is decide on the purpose of the purchase. Different devices are bought to solve different problems. It all depends on the specific type of equipment and its technical characteristics.
2. If you are buying a built-in loudspeaker model, you should agree on its parameters and parameters of the roomin which the device will be installed. Most often, two-lane copies are taken for this. When choosing this model, discuss with the seller for which setting you are buying it.
3. pay attention to frequency range of technology... It must be remembered that the human ear is only capable of picking up frequencies in the range from 20 Hz to 20 kHz. None of the existing speakers can reproduce absolutely the entire audible frequency range. The quality of sound reproduction in any case will differ from the required.
4. Consider the nominal equipment power. A wide variety of loudspeaker models are available today. There are low-power, medium, and powerful options that produce a very loud sound.
5. Make sure you are comfortable using the device. This is especially true for desktop and portable options that must be carried in hands. It is advisable to make sure that the technique will be convenient to use, even in the store and before payment.
6. Attentively inspect the audio structure, which were going to buy. It doesn't matter for what purpose you choose the loudspeaker. Any model must be assembled "conscientiously", without loose or damaged parts. Make sure all required structural elements are in place. None of the possible surfaces of the equipment should have no scuffs, no chips, no scratches, or any other imperfections.
7. Many buyers underestimate the importance of attractive design of a quality loudspeaker. Of course, this is not the most important and weighty criterion, but it is also better to take it into account.This is especially true when the equipment is purchased for advertising campaigns and presentations.
8. Today, many well-known and large brands produce high-quality and reliable loudspeakers of various categories. If you decide to purchase a durable model that will not break down and give a good sound, then you not worth saving, buying cheap Chinese products of poor quality.

Loudspeakers are not available in all stores. Such things you need to buy in specialized retail outlets, where they will be sold accompanied with warranty coupons... A lot of high-quality branded models are found in large online stores, where you can choose the option you like and place an order. It is strongly discouraged to buy such equipment from questionable stores or the market. Here you can hardly find a device that will delight you with good sound. And the lifespan of these products is often short, and the build quality is poor.

For an overview of the Spartak RD 8S megaphone loudspeaker horn, see the next video.