It's always nice to listen to music or watch a good movie with high-quality sound. Today, the choice of audio systems is simply huge, and it is easy for a person who is poorly versed in such technology to get confused. Find out how to choose speakers for home use, taking into account your preferences. Acoustic system must be not only attractive appearance, but also optimal parameters for specific purposes.

Any speaker system consists of a configuration that can be designated by the numbers 2.0, 2.1, 3.1,5.1, 7.1. The first number in this marking indicates the number of speakers (satellites), and the second indicates the presence of a subwoofer. That is, if the speakers are designated as 2.0, this means that they do not have a separate low-frequency speaker (subwoofer), and the lower bass is built into the speakers themselves.

Dividing the system into main speakers and a subwoofer allows you to get higher quality, surround sound, creating the effect of presence. The more accompanying speakers the system has, the better and more impressive the sound.

Let's look at what types of columns exist:

1. Computer. The simplest and budget speakers for PC do not have a subwoofer. There are those that consist of a 2.1, 3.1 system. As a rule, computer speakers are small in size and designed for desktop placement. The speakers can be connected not only to a desktop PC, but also to a laptop, tablet, or smartphone.
2. Floor. These are more powerful and larger audio systems used in home theaters and large rooms. To reduce vibrations on the floor and walls and make the sound clearer, floor-standing speakers are equipped with special stands made of stone (granite, marble). Cheaper models have rubberized stands. The floor-standing type of acoustics is more sensitive than others and is more demanding on amplifiers.
3. Ceiling. Not too large speakers placed under the ceiling can be used both as front satellites and as two-channel audio systems. They are suitable for small spaces and are very practical because they take up little space.
4. On racks. These speakers are placed on the floor, but differ from ordinary floor-standing ones. They are not large, and their speakers are designed to be installed at a certain height. It is thanks to the correct placement that you can get spectacular, surround sound. The height of the stands in most models is adjustable.
5. Soundbars. The difference between such acoustics is that all elements and channels are located in one horizontal panel. Externally, the speaker looks primitive and simple, but in terms of sound quality it can surpass 5.1 and 7.1 systems. This effect is achieved thanks to high-tech algorithms that supply signals from the amplifier to the speakers separately. This is one of the most expensive species audio systems for the home.
6. Portable. Usually this is just one column that can work autonomously from 4-5 to 20 hours. Connection with devices occurs via Bluetooth. This type of acoustics is intended for use in a small room or outside the home. Portable speakers have become an excellent solution for recreation; they are loved by young people and travelers. High-quality mobile speakers have quite powerful, clear and spacious sound. Although, of course, this cannot be called a full-fledged audio system.

These are the main types of home speakers that can be purchased today on our market.

Main characteristics and their importance

Large and beautiful-looking speakers may have very weak characteristics. Conversely, compact and unprepossessing ones are capable of surpassing larger systems in power and clarity of sound. The sound quality depends on the technical parameters. To choose truly good speakers, you need to learn to understand the basic performance criteria.

Speaker power

It is worth immediately noting that the power indicator is not an indicator of volume. This factor indicates how long the speaker can sound at maximum volume without distortion, wheezing or other interference. It is important that the power level of the speakers be lower than the power level of the amplifier. Otherwise, the system will very quickly burn out from excessive load.

The parameters distinguish between two types of power - peak and root mean square. Regardless of what type of speakers you choose, you should pay attention to the RMS indicator. It determines how long a speaker can play at high volumes without distortion or overload.

The optimal indicator for home acoustics can be considered the total power of the speakers in the range of 40-70 W.

Number of lanes

This characteristic indicates the number of speakers in the column. For example, small speakers most often have only one stripe. 3.1 systems can consist of 2-way speakers. Three-way audio systems are considered one of the best, where the division is into high, mid and low frequencies. There are also more advanced systems that divide the sound into 4-5 and even 7 channels.

The more bands an acoustic system has, the better and more versatile its sound.

Amplitude-frequency characteristics

Amplitude-frequency response (AFC) is the dependence of the amplitude of sound vibrations at the output on the frequency of the reproduced signal. The frequency response is usually depicted on graphs. The range of these frequencies is displayed in hertz and kilohertz, and any deviations in decibels. In the equipment passport it is indicated in hertz (Hz) and kilohertz (kHz). This is an important indicator, but for a person who does not understand all the intricacies of musical equipment, it is useless.

If to speak in simple words, then the smoother the frequency response graph when the speaker sounds, the better. Sudden fluctuations and bursts indicate that the speakers are distorting the sound.

To choose the right audio system based on frequency response parameters, it is better to consult with a specialist.

Audio coding system

Today, there are various digital audio encodings that allow you to reproduce it in volume. First the “stereo” effect appeared, then formats such as Dolby Stereo Surround. These encodings involve dividing the sound into several channels, thereby achieving the effect of presence and complete immersion in the sound.

Not every speaker system is capable of reading and reproducing sound in multi-channel encodings. Single-way speakers can also provide stereo sound, but they will not be able to convey all the luxury of a multi-channel system.

Those who want to listen to audio files in modern surround encodings on their speakers should buy 3.5 or 7-channel speakers and a player that reads formats such as Blu-ray.

Phase inverter

High-quality modern speaker systems are equipped with a bass reflex. This is a kind of pipe or hole located in the speaker housing. The resonance of this element allows you to expand the low-frequency range. In systems consisting of small satellites and a subwoofer, the bass reflex is installed only in the low-frequency speaker.

For small rooms, it is better to choose speakers with a side or front bass reflex placement. In large halls, speakers with side and rear placement of this part are used.

Housing material

Speakers are made from the most different materials. The quality of the cabinet also affects the sound.

Types of materials from which audio system housings are made:

• plastic;
• natural wood;
• glass;
• plexiglass;
• marble or granite;
• metal.

The most popular today are plastic speakers. Good durable plastic does not distort the sound and is quite suitable for lining speakers. In addition, it is the cheapest material.

The best equipment is considered to be wooden. Natural wood has unique acoustic properties and improves sound. Stone is suitable for large and low-frequency speakers; it muffles bass distortion. Systems made of MDF and chipboard would be a good choice. But glass and metal do not have the best effect on the reproducibility of sound notes. A lot depends on the number of bands, the size of the speakers and the room.

Additional functionality

TO additional functions This includes wireless control (using a remote control), as well as the ability to configure each speaker separately. Such options are present in more expensive models.

Some systems are equipped with a display that shows all the current settings. A very convenient extension that allows you to configure the speakers not only auditorily, but also visually.

Some speakers may have an additional wall mount. This is very convenient for those who have a small computer desk (if the system is purchased specifically for a PC).

If we compare wireless speakers and ordinary ones, then in terms of sound quality the latter clearly win. Despite the convenience of portable audio systems, the wireless signal loses some of the power and purity of the sound.

Rating

So, now you know how to choose speakers wisely, taking into account their parameters and characteristics. We present a rating of the best home models with optimal parameters and good reviews.

A small stereo pair of speakers (2.0) has an output power of 24 W and a front bass reflex. The acoustics are designed for tabletop placement. The speakers are perfect for a computer. The body is made of MDF in a stylish black color. The equipment looks expensive and solid.

The model has a frequency range of 70-20000 Hz and a class D digital amplifier. The speakers are designed using a 2-way design, based on 4-inch bass speakers. On the back of the case there are toggle switches for adjusting the reproduced volume and bass level.

• stylish design;
• there are settings on each column;
• good, strong bass;
• clear sound, no hissing or wheezing;
• inexpensive.

• the switch is at the back, it’s not always convenient to reach for it;
• few high frequencies;
• Not very high quality wires.

The Edifier R12U model is a practical choice of speakers for a tablet or computer. Small but powerful speakers squeeze out a total of 4 watts. On the front panel of the acoustics there is a bass reflex and a toggle switch. The body is made of plastic and comes in 3 colors: red, black, white.

The range of reproduced frequencies of the speakers is 180-20000 Hz. The speakers are connected via a USB connector. The model also has a mini jack linear output and a headphone jack.

• light, compact;
• there are controls on the front of the case;
• very good bass;
• absolutely silent when inactive;
• cheap.

• at maximum volume they may wheeze a little (depending on the music);
• glossy plastic gets dirty quickly;
• If you use it for a long time and at loud volumes, they get very hot.

The 2.1 speaker system in an elegant design has a total output power of 38 W. A distinctive feature of the model is the possibility of desktop and wall placement. The body is made of MDF, which has a positive effect on sound quality. The range of reproduced frequencies is 20-20000 Hz. On the front of the case there are controls through which you can adjust the treble and bass. The bass reflex on the subwoofer significantly enhances the bass.

The sound quality of this acoustics will please both computer game lovers and music lovers.

• clear, high-quality sound on all ranges;
• high level of strength, last a very long time;
• very high quality casing that does not wear out over time;
• very powerful volume, glass may rattle in a small room;
• possibility of adjusting bass and treble;
• no noise from mobile phone.

• short wires.

The SOLO-2 model is positioned as an audio system for a player or computer. Its power is enough to fill a large room in the house with sound. The equipment body is made of MDF with a dark wood look. The bass reflex port is located on the rear panel. The total power of the speakers is 60 W, which is an excellent indicator. On the rear panel there are controls for volume, treble and low frequencies. Audio equipment uses a powerful amplifier with a chip from ST Microelectronics. This keeps distortion at high volumes to a minimum.

If we compare models in the rating, the first place should be given to the SVEN SPS-820 acoustics. She has the best price-quality ratio. It will allow you to arrange a real disco at home, enjoy immersion in computer game, watch a good movie comfortably.

But we should not forget that everything depends on the personal preferences of each user. And if speakers are needed only for light musical accompaniment while working on a PC, then there is no need to buy expensive ones. Whereas for music lovers, it makes sense to fork out for a more “sophisticated” audio system.

First of all, let's understand the terms, since the concepts of “loudspeaker”, “column”, “speaker”, “speaker system” are often used at random, creating a fair amount of confusion.

Speaker is a device designed to effectively radiate sound into the surrounding space in an air environment, containing one or more loudspeaker heads with acoustic design and electrical devices (filters, regulators, etc.).

In the domestic technical literature, an erroneous practice has developed, according to which the term “loudspeaker” (LS) is used mainly for a single loudspeaker (in foreign catalogs it is defined as loudspeaker units or loudspeaker drive element, or driver). In accordance with the requirements of GOST 16122-87, a single loudspeaker must be designated as speaker head .

The term is often applied to a set of Hi-Fi and Hi-End class loudspeakers acoustic system (AC) (acoustical system or loudspeaker system). The sound system includes acoustic speakers .

Depending on their purpose, speakers vary significantly in parameters, design and construction. The main types of acoustic systems presented on the modern market can be divided into several categories depending on their area of ​​application:

• Speakers for home use, which in turn can be divided into systems:
• mass;
• Hi-Fi and High-End categories;
• Speakers for home audio video complexes of the “Home-Theater” type;
• for modern computer systems (AC Multi-Media), etc.;
• Speakers for sound and sound reinforcement systems, including conference systems and speech translation systems (these include, in particular, ceiling speaker systems);
• concert and theater speakers;
• studio speakers;
• automobile (and transport) speakers;
• Speakers for individual listening (stereo headphones).

Speaker device

AC may be single lane And multi-lane . Single-band speakers are used, as a rule, in mass-produced equipment in the budget sector. High-quality speakers (Fig. 1) use a multi-way design principle, since the use of one broadband loudspeaker head does not allow for high quality sound.

The AC usually consists of:

• speaker heads, each of which (or several simultaneously) operates in its own frequency range;
• corps;
• filtering and correcting circuits, as well as other electronic devices (for example, for overload protection, level indication, etc.);
• audio cables and input terminals;
• amplifiers for active speaker systems and crossovers (active filters).

Rice. 1. Defender sound system

Speaker heads

Loudspeaker heads are classified by operating principle, by emission method, by transmitted frequency band, by area of ​​application, etc.

According to the principle of action , i.e. Based on the method of converting electrical energy into acoustic energy, loudspeakers are divided into electrodynamic, electrostatic, piezoceramic (piezo-film), plasma, etc.

The vast majority of loudspeaker heads are electrodynamic ("dynamic" or simply "speakers"). Their operating principle is based on the movement in a constant magnetic field of a conductor or coil powered by alternating current (Fig. 2).

Rice. 2. Electrodynamic coil loudspeaker

The head of the electrodynamic loudspeaker consists of a moving system, a magnetic circuit and a diffuser holder (1).

The moving system includes a suspension (2), a diaphragm (3), a centering washer (4), a dust cap (5), a voice coil (6) and flexible leads.

When alternating current is passed through a voice coil placed in the radial gap of a magnetic circuit, a mechanical force will act on it. Under the influence of this force, axial vibrations of the coil and the diaphragm attached to it occur. The design of an electrodynamic loudspeaker is very similar to the design of a dynamic microphone, so, in principle, you can make a weak loudspeaker head from a dynamic microphone, and a microphone from a loudspeaker head. It is clear that all this will work disgustingly, but it will work.

Rice. 3. Ribbon speaker

Ribbon speakers (Fig. 3) use a thin metal strip that is placed in a magnetic field between the poles of a magnet and serves as both a current conductor and an oscillating radiating element.

Tape heads are much more effective than dynamic, piezoelectric and others, because if the area of ​​a conical or dome diffuser is the area of ​​a visible circle, then the active area of ​​a tape emitter is the full development of the folded membrane (the effective area is 2.5 times larger than the projection area of ​​the folded tape). Thus, less movement of the diffuser is required to achieve the required sound pressure level.

Rice. 4. Electrostatic loudspeaker

Electrostatic loudspeakers (Fig. 4) use a radiating element in the form of a thin metallized film (1) with a thickness of about 6...10 microns, placed between perforated electrodes (2) (i.e., it is a variable capacitor, where one of the plates is a thin metallized movable membrane). A high polarizing voltage of the order of 8...10 kV is applied between the membrane and the electrodes. An alternating sound voltage, under the influence of which the membrane vibrates and emits sound, is supplied to fixed electrodes. Loudspeakers of this type provide purity and transparency of sound due to low levels of transient distortion.

Rice. 5. Final range of electrostatic loudspeakers

Rice. 6. Electrostatic speaker center speaker. Model 200

On fig. 5 shown the lineup electrostatic loudspeakers Final, and in Fig. 6 – close-up of the central speaker.

Rice. 7. Piezo film loudspeaker

Piezoceramic (piezo film) loudspeakers (Fig. 7) are used mainly as a high-frequency link in acoustic systems. As an exciting element, they use a bimorph element obtained by connecting two plates (1), (3) made of piezoceramics (titanium zirconate, barium titanate, etc.). The bimorph element is fixed on both sides; when an electrical signal is supplied, bending deformations occur in it, which are transmitted to the diaphragm connected to it (2). A variation of this type of loudspeaker is piezo-film emitters; they use high-polymer films, which, using specially developed technology, are given piezoelectric properties (when polarized in a strong magnetic field). If such a film is shaped into a dome or cylinder, then under the influence of an alternating voltage applied to it, it begins to vibrate and emit sound; such loudspeakers do not require the use of a magnetic circuit.

According to the method of emitting acoustic energy, loudspeaker heads are divided into direct radiation heads, in which the diaphragm emits sound directly into the environment, and horn heads (Fig. 8), in which the diaphragm emits sound through the horn. If a horn loudspeaker has a pre-horn chamber, then it is called a narrow-throat horn loudspeaker, and if only a horn is used, then it is a wide-throated horn loudspeaker.

Rice. 8. Horn loudspeaker

Horn loudspeakers are widely used in creating sound systems for streets, stadiums, squares, sound reinforcement systems in various rooms, high-quality household systems, warning systems, etc.

The reasons for the spread of horn loudspeakers are due, first of all, to the fact that they are more efficient, their efficiency is 10-20% or more (in conventional loudspeakers the efficiency is less than 1...2%); In addition, the use of rigid horns allows the formation of a given directivity characteristic, which is very important when designing sound reinforcement systems. However, when using horn loudspeakers, problems arise due to the fact that in order to emit low frequencies it is necessary to significantly increase the size of the horn, and high sound pressure levels in the pre-horn chamber create additional nonlinear distortions.

The design of loudspeaker heads depends on the frequency band in which they must operate. Based on this feature, loudspeakers are divided into:

• broadband (OO “full-range”);
• low-frequency (reproducible range approximately 20-40...500-1000 Hz) (“woofer”, “subwoofer”);
• mid-frequency (range 0.3-0.5...5-8 kHz) (“mid-range”);
• high-frequency (1-2..16-30 kHz) (“tweeter”), etc.

Most of the power of audio signals usually comes from low frequency GG, so they must withstand loads of up to 200 W or more, while maintaining thermal and mechanical strength. These GGs have a low resonant frequency (16...30 Hz) and must be designed for a large stroke of the moving system up to ±12...15 mm.

The appearance of a modern low-frequency GG for high-quality speakers is shown in Fig. 9.

The main radiating element of a loudspeaker is the diaphragm. The diaphragms of modern low-frequency GGs are made from complex compositions based on natural long-fiber cellulose with various additives. Sometimes such a composition includes up to 10-15 components. Synthetic film compositions based on polyolefins (polypropylene and polyethylene) and composite materials based on Kevlar fabric are increasingly used.

Rice. 9. Woofer

Speakers for home theaters (especially the center and front channels, as well as the subwoofer) require the use of carefully shielded low-frequency generators.

Midrange speakers (MF GG) are used in the frequency range from 200... 800 Hz to 5...8 kHz, where the sensitivity of hearing to all types of distortion is maximum, therefore the requirements for their quality are the most stringent.

Tweeters (HF GG). (Fig. 10). Requirements for them have increased sharply in recent years due to an increase in the spectral power density in the high-frequency part of the spectrum in modern electronic music, an expansion of the frequency and dynamic range of programs reproduced by digital sound reproduction equipment, etc.

In modern speakers, high-frequency GGs are used, as a rule, in the frequency range from 2...5 to 30...40 kHz. It is extremely difficult to ensure equivalent high-quality sound reproduction in such a wide range using one GG. Therefore, most of the currently produced HF GGs are used in the range from 2... 5 to 16... 18 kHz, and in some speakers additional small-sized HF GGs are installed (reproducing frequencies from 8... 10 to 30... 40 kHz).

Rice. 10. HF GG

Ceiling speakers

Ceiling speakers are typically electrodynamic cone speakers housed in plastic or metal housings. They are used for sounding rooms and in emergency warning systems for buildings. Thanks to the large angle of the sound radiation pattern and the wide range of reproduced frequencies, ceiling speakers are capable of reproducing sound quite well, in addition, they fit harmoniously into almost any interior.

Ceiling speakers provide a more uniform sound distribution throughout the room compared to other speakers and do not require the installation of powerful amplifiers. Their use is especially effective for sounding large rooms with a ceiling height of up to 5 m.

For ease of installation, the ceiling loudspeaker housing is equipped with special devices: spring-loaded stops, runners or brackets. Many speakers are attached to ceiling tiles with screws. Unlike “conventional” PA systems, ceiling speaker systems are high voltage, with a typical line voltage of 100V, so ceiling speakers have built-in transformers.

When designing a public address system, the calculation of the required number of ceiling loudspeakers and their placement diagram (Fig. 11) is made based on the required sound pressure level at listener ear level (usually an average value of 1.5 m is taken). For rooms with a ceiling height of less than 5 meters, such a calculation is not difficult and is made using approximate formulas. Table 1, for a given ceiling height and room area, shows the number of ceiling speakers that will give best quality sound and the most uniform distribution of sound waves.

Rice. 11. Layout of ceiling speakers

The S parameter in the table is the approximate area covered by one ceiling loudspeaker:

S = (2x(H – 1.5 m))2, where H is the ceiling height.

Table 1. Calculation of the warning system

In the table:
P – sound pressure at 1.5 m when the ceiling loudspeaker is operating at full power;
P/2 – sound pressure at 1.5 m when the ceiling loudspeaker operates at half maximum power;
H – ceiling height;
S – area of ​​the room.

If the ceiling height is more than 5 meters, installing ceiling speakers is not recommended. However, if you must use in-ceiling speakers, you should take steps to improve the uniformity of sound distribution and reduce the effect of reverberation (echo). If ceiling speakers are placed too close together, the sound will be distributed unevenly at listeners' ear level. If you increase the distance between adjacent speakers, the sound pressure level may not be sufficient for good audibility. Increasing the sound level of the speakers in this case entails an increase in reverberation, especially in rooms decorated with glass, marble, etc. Reverberation can be reduced using sound-absorbing materials: carpets, tapestries, curtains, etc.

On fig. Figures 12 and 13 show examples of in-wall and mounted ceiling speakers from Kramer Electronics.

Speaker housing. Main types of buildings and their purpose

The speaker housing performs a variety of functions. In the low-frequency region, it blocks the “acoustic short circuit” effect that occurs due to the addition of emitted sound from the front and rear surfaces of the diaphragm in antiphase, which leads to the suppression of low-frequency radiation.

The use of a housing makes it possible to increase the intensity of radiation at low frequencies, as well as to increase the mechanical damping of loudspeakers, which makes it possible to “smooth out” resonances and reduce the unevenness of the amplitude-frequency response. The housing has a significant impact not only in the low frequencies, but also in the mid and high frequencies. A properly designed and manufactured enclosure has a huge impact on sound quality.

When designing speaker enclosures, design options such as an endless screen, a closed enclosure, an enclosure with a bass reflex, a labyrinth, a transmission line, etc. are most often used.

Infinite screen occurs when speakers are installed in the wall of a room with a sufficiently large volume behind it. This type of speaker installation is characterized by a “booming” effect at low frequencies, since there is no damping.

Closed housing. Modern speakers mainly use closed compression-type enclosures. The principle of operation of compression design is that they use loudspeakers with a very flexible suspension and a large mass, i.e. low resonant frequency. In this case, the elasticity of the air in the body becomes the determining factor; it is it that begins to make the main contribution to the restoring force applied to the diaphragm.

Housing with bass reflex– a housing in which a hole is made, which allows the use of radiation from the rear surface of the diffuser. The maximum effect is achieved in the region of the resonance frequency of the oscillatory system, formed by the mass of air in the hole or pipe and the mass of air in the housing.

Cases with a bass reflex (Fig. 14 a) have many varieties. A housing using a special pipe inserted into the hole allows you to reduce the dimensions of the housing and adjust the bass reflex by adjusting the dimensions of the pipe (Fig. 14 b).

If a passive (i.e. without a magnetic circuit) loudspeaker is installed in the housing opening, the oscillations of which are excited by fluctuations in the volume of air enclosed in the housing, then such a housing is called a housing with a passive radiator (Fig. 14 c).

Rice. 14. Speaker housing with various bass reflex options: a – bass reflex; b – bass reflex with pipe; c – passive radiator

Labyrinth is a variant of the case with a bass reflex, in which special partitions are installed. When the length of the labyrinth reaches 1/4 of the wavelength at the resonant frequency of the woofer, it acts similarly to a bass reflex. The use of a labyrinth expands the possibilities for tuning to lower frequencies. Harmonic resonances from the main resonant frequency of the pipe are damped by sound-absorbing materials on the walls of the housing (Fig. 15 a).

Rice. 15. Speaker housing of labyrinth type (a) and transmission line type (b)

Transmission line- This is a type of labyrinth. It differs from a labyrinth in that the entire volume of the body is filled with sound-absorbing material, and the cross-section of the line is made variable - larger at the cone, smaller at the hole (Fig. 15 b). This type of enclosure is very difficult to configure.

If two identical GGs are installed in the case on one bass reflex, then this is called “low-frequency design with a symmetrical load.” This design is often used in subwoofers.

Speakers with smoothed corners, a streamlined shape, and an asymmetrical oscillator arrangement sound better, however, producing cabinets for such speakers is difficult and expensive, so the vast majority of speakers are produced in rectangular-shaped cabinets. To reduce diffraction effects at the corners of the front panel, special measures are used, including the placement of sound-absorbing materials (“acoustic blanket”), optimization of the ratio of the dimensions of the front panel and the depth of the cabinet, selection of asymmetrical arrangement of loudspeakers, etc.

The desire to shift diffraction peaks and dips in the frequency response to a higher frequency region and thereby reduce their influence forces the use of the narrowest front panels. The complex external configurations of many modern speakers are driven not only by aesthetic considerations, but also by the desire to reduce diffraction effects. To reduce sound radiation from the walls of speakers, they usually try to increase their rigidity and mass.

In modern speakers, the housing is a rather complex and expensive structure (Fig. 16). As a criterion for the effectiveness of the measures taken to soundproof the enclosure, it is generally accepted that the difference between the sound pressure level emitted by the walls of the enclosure and the sound pressure level from the acoustic system as a whole must be at least 20 dB.

Rice. 16. Section AC

In addition to objective measurements, during design, speakers are listened to in enclosures of various designs.

Filtering and correction circuits

It is almost impossible or difficult to ensure high-quality sound reproduction using single-way speakers, so they are used only in budget decisions, for example, in cheap computer speakers. High-quality speakers, with rare exceptions, are multi-way. In order to supply each GG with signals of its own frequency subrange, electrical isolation filters (“crossovers”) are used.

Most speakers for home use use the so-called. passive filters that are connected between the amplifier and loudspeaker (Fig. 17).

Rice. 17. Passive filters (“passive crossovers”) in speakers

Passive filters are usually placed inside speakers, increasing their weight and dimensions. Passive filters in speakers are of first, second, third and fourth order. The slope of the first order filters is 6 dB/octave, the second is 12 dB/octave, the third is 18 dB/octave and the fourth is 24 dB/octave.

The simplest filters are first-order filters; they take up little space and are inexpensive, but have insufficient passband rolloff steepness. A positive feature of these filters is the absence of phase shift between the tweeter (HF head) and the other speaker.

Second-order filters (or Butterworth filters, named after the creator of the mathematical model of these filters) have higher sensitivity, but give a phase shift of 180 degrees, which means that the membranes of the HF head and the other speaker are not synchronized. To fix this problem, you need to change the polarity of the wires on the Twitter.

Third-order filters have good phase characteristics for any connection polarity. On fig. 18 shows the frequency response of a third-order filter, and Fig. 19 – its electrical diagram.

Rice. 18. Frequency response of a third-order filter

Rice. 19. Wiring diagram third order filter

Rice. 20. Frequency response of a three-band filter

In three-band speakers, the frequency response of the filter looks as shown in Fig. 20.

Fourth-order Butterworth filters have a high passband rolloff slope, which dramatically reduces the interference of speakers in the frequency separation region. The phase shift is 360 degrees, that is, in practice it is absent. However, the problem is that the phase shift of such filters is not constant, which can cause unstable operation of the speakers. Linkwitz and Riley succeeded in optimizing the fourth-order filter circuit in relation to speakers. Their filter consists of two series-connected second-order Butterworth filters for the HF GG and for the LF GG. This filter has no phase shifts and allows for time correction for speakers that do not emit sound in the same plane. These filters provide the best acoustic performance.

“Active” speakers with built-in multi-band amplifiers use active filters connected before the amplifier and also called crossovers (Fig. 21).

Rice. 21. Using crossovers

Compared to passive filters, active filters have a number of advantages: smaller dimensions, better tunability of crossover frequencies, greater stability of characteristics, etc. However, passive filters provide more dynamic range, lower noise level and nonlinear distortion. Their disadvantages include temperature instability, which leads to a change in the shape of the frequency response when the level of the input signal increases (the so-called “power compression”), as well as the need for careful selection of high-precision elements (resistors, capacitors, etc.), to the spread of parameters which filter characteristics can be very sensitive. In recent years, a number of foreign companies have begun to use digital filters in acoustic systems, providing real-time filtering, correction and adaptation functions to real listening conditions.

In addition to filters, modern acoustic systems often use electronic devices to protect loudspeakers from thermal and mechanical overloads. Protection from both long-term and short-term (peak) overloads is carried out using various versions of threshold circuits, the response thresholds of which must be less than the thermal constants of the loudspeaker heads (T = 10...20 ms). In addition, many household systems use various options overload indication.

Main characteristics of the speakers

There are quite a lot of characteristics of speakers, some of them are of greater importance for the user, others are less important, domestic and foreign characteristics of speakers and methods for measuring them do not always coincide. We will briefly consider only the main characteristics of the speaker.

Efficient worker (effectively reproduced) frequency range - a range within which the sound pressure level developed by the speaker is not lower than a given one, in relation to the level averaged in a certain frequency band. In the recommendations of IEC 581–7 minimum requirements to this parameter are 50 – 12500 Hz with a drop of 8 dB relative to the level averaged in the frequency band 100 – 8000 Hz.

The value of this characteristic greatly influences the natural sound of the acoustics. The closer the operating range of the speaker is to the maximum range perceived by the human hearing organs (16 – 20,000 Hz), the better and more natural the speaker sounds. The effective operating range depends on the characteristics of the loudspeaker heads, the acoustic design of the speakers and the parameters of the crossover filter.

At low frequencies, the volume of the speaker cabinet plays a decisive role. The larger it is, the more efficiently low frequencies are reproduced, which is why subwoofers in particular are always quite bulky. There are usually no problems with reproducing high frequencies, since modern tweeters can even reproduce ultrasound. Often the range of reproduced frequencies of speakers exceeds the upper limit of human audibility. It is believed that in this case the timbre of a complex phonogram, for example, symphonic music, is more accurately conveyed. Typical values: 100 – 18000 Hz for bookshelf acoustics and 60 – 20000 Hz for floor-standing ones.

Serious speaker manufacturers usually provide a graph of the sound pressure developed by the speaker depending on frequency (amplitude-frequency response (AFC) graph), from which you can determine the effective operating frequency range of the speaker and the unevenness of the frequency response.

The degree of unevenness of the frequency response is characterized by the ratio of the maximum value of sound pressure to the minimum, or according to another method, the ratio of the maximum (minimum) value to the average, in a given frequency range, expressed in decibels. The recommendations of IEC 581-7, which define the minimum requirements for Hi-Fi equipment, indicate that the frequency response unevenness should not exceed ±4 dB in the range of 100 - 8000 Hz.

Directional characteristic allows you to evaluate the spatial distribution of sound vibrations emitted by an acoustic system, and optimally position the acoustic systems in different rooms. This parameter can be judged by the loudspeaker's radiation pattern, which is the dependence of the sound pressure level on the angle of rotation of the loudspeaker relative to its operating axis in polar coordinates, measured at one or several fixed frequencies. Sometimes the decline in the amplitude-frequency response when the speaker is rotated at a certain fixed angle is displayed on the main graph in the form of additional branches of the frequency response.

Characteristic sensitivity is the ratio of the average sound pressure developed by the speaker in a given frequency range (usually 100 - 8000 Hz) on the operating axis, reduced to a distance of 1 m and an input electrical power of 1 W. In most Hi-Fi speaker models, the level of characteristic sensitivity is 86-90 dB (in technical literature, dB/m/W is often indicated instead of dB). There are high-quality wideband speakers with a sensitivity of 93 - 95 dB/m/W and more.

Characteristic sensitivity determines what dynamic range the speaker can provide. The wide dynamic range allows you to reproduce complex musical works with great reliability, especially jazz, symphonic, and chamber music.

Harmonic distortion factor characterizes the appearance during the conversion process of spectral components that were absent in the original signal, distorting its structure, that is, ultimately, the accuracy of reproduction. This is a very important parameter, since the contribution of speakers to the total nonlinear distortion coefficient of the entire audio path, as a rule, is maximum. For example, the coefficient of nonlinear distortion of a modern amplifier is hundredths of a percent, while the typical value of this parameter for speakers is a few percent. As the signal power increases, the nonlinear distortion factor increases.

Electrical (acoustic) power – determines the sound pressure level and dynamic range (taking into account the characteristic sensitivity) that the speakers can potentially provide in a certain room.

Several types of power, defined by different standards, are used:

Characteristic power , at which the speaker provides a given level of average sound pressure. The IEC recommendations set this level to 94 dB at a distance of 1 meter.

Maximum (maximum) noise or rated power at which the speaker can operate for a long time without mechanical and thermal damage when tested with a special noise signal, close in spectrum to real music programs (pink noise). According to the measurement methodology, it coincides with the nameplate power defined in domestic standards.

Maximum (limit) sinusoidal power – the power of a continuous sinusoidal signal in a given frequency range, at which the speaker can operate for a long time without mechanical and thermal damage.

Maximum (ultimate) long-term the power that the acoustics can withstand without mechanical and thermal damage for one minute, with the same test signal as for the rated power. The tests are repeated 10 times with an interval of 1 minute.

Maximum (limit) short-term the power that the speaker can withstand when tested with a noise signal with the same distribution as for the nameplate power for 1 second. The tests are repeated 60 times with an interval of 1 minute.

Peak (maximum) musical power – a favorite parameter for characterizing speakers of unknown origin. The measurement technique, defined by the German standard DIN 45500, is as follows: a signal with a frequency below 250 Hz and a duration of less than 2 seconds is supplied to the speaker. The acoustics are considered to have passed the test if there are no audible distortions. It is clear that “distortions noticeable to the ear” can be understood as anything. As a result, stickers like “P.M.P.O.” appear on speaker cabinets from unknown manufacturers. … (or Musical Power…)…100!, …200! and even... ...1000 Wt! It is clear that there is no need to talk about any quality sound created by such speakers.

When choosing speakers for ULF, it is desirable that the real maximum power of the speaker exceeds the power of the amplifier by approximately 30 percent or more. In this case, you will be insured against failure of the acoustics due to the supply of a signal to it at an unacceptably high level. Of course, good speakers have overload protection circuits, but it’s better not to take risks.

What amplifier power is sufficient for high-quality sound reproduction? This is largely determined by the parameters of the room, the characteristics of the acoustic systems, and the needs of the listener himself. When choosing an amplifier for sounding a small living room, we can assume that the power of the amplifier should be at least 20 W.

Most common values electrical (input) resistance (impedance): 4, 8 or 16 ohms. This parameter is important when choosing an amplifier with which the speakers will work. You should use speakers with a resistance corresponding to that specified in the amplifier's data sheet. Such a solution will ensure ideal matching of the characteristics of the acoustics and amplifier, that is, the best sound quality.

Measuring the characteristics of speakers in conditions different from the conditions of specially equipped acoustic laboratories of manufacturing plants is an extremely complex, expensive matter and, most importantly, gives very approximate results. High-quality sound analyzers and measuring microphones with preamplifiers that meet all international measurement requirements are extremely expensive and not every Russian company can afford to purchase them. True, modern measurement techniques in most cases will make it possible to do without an acoustically attenuated chamber.

Audio cables

Audio cables are, at first glance, the least important component of the audio subsystem of an installation or home theater, so they are often purchased as a spare item. And they make a serious mistake.

It is clear that any cable affects the signal passing through it. The question is how exactly the cable affects the signal and how strong this effect is.

The choice of audio cables is determined by the quality of the audio signal on the one hand and structural and financial considerations on the other. Indeed, some installations require laying hundreds of meters of audio cables. You can calculate how much, for example, silver microphone cables with a total weight of 100 kg will cost...

The conductors in any electrical cable or wire are metals. Audio cables primarily use copper and silver. In 1984, Hitachi released the SAX-102 interconnect cable, which immediately attracted the attention of professionals. It was made from so-called oxygen-free copper OFC (Oxygen Free Copper). Now such copper is used by almost all specialized “cable” companies. What is good about oxygen-free copper? A conductor metal can be thought of as a series connection of metal granules. Inside each granule, the crystal structure remains ideal, but the interfaces between granules disrupt the crystal lattice. As a rule, the causes of the appearance of interfaces are films of oxides and oxygen compounds with metals. By molding and stretching the OFC in a specific manner, the length of the ideal granules increases. Regular high purity copper contains about 5,000 granules per meter of cable. Improvements in OFC technology have led to the emergence of higher quality oxygen-free high-conductivity copper OFHC (Oxygen Free High Conductivity), the number of granules per meter in which was 1000. There are other types of technology for producing oxygen-free copper wires.

Similar technologies are applied to silver conductors. The result is long-grained, highly purified silver, such as AudioQuest's FPS (Functionally Superior Silver) or PSS (Perfect Surface Silver). These are very expensive wires. Silver is often used as a cladding coating on copper wire, and to eliminate the potential influence of inhomogeneities on signal transmission, the surface is polished to a mirror finish.

The main insulators used for audio wires and cables in household appliances are polyethylene, polyvinyl chloride and fluoroplastic (known as Teflon). For external coatings of cables, artificial rubbers, silicone rubbers, polypropylenes, etc. are used. Polyethylene is most often used; fluoroplastic has the best dielectric characteristics, but it is relatively expensive, which limits its use. Sometimes foamed polyethylene or fluoroplastic is used as an insulator.

Since audio cables connect the amplifier to the speakers and operate with fairly large currents, developers first of all pay attention to the active resistance of the conductor: the lower it is, the better. Firstly, because the ohmic resistance of the cable is connected in series with the output resistance of the ULF and the input resistance of the speaker, and a relatively high-resistance connecting wire can sharply deteriorate the quality of operation of the ULF and speaker, and, secondly, according to the Joule-Lenz law, the thermal heating of the wire is proportional to the second degree of current flowing through it. Reducing the ohmic resistance of conducting lines is achieved by increasing their cross-section. Therefore, audio cables are quite thick. Acoustic wires are relatively low-frequency (the operating range is within 4-5 orders of magnitude: from a few hertz to hundreds of kilohertz). And yet, most developers, having achieved a minimum value of resistivity (0.001–0.05 Ohm/m), try to reduce the inductance of the wire (the typical value of specific inductance is 0.2–0.5 μH/m). Almost all wires, with the exception of flat ribbon wires, are made in the form of bundles assembled from individual thin wires. The simplest ones are a pair of insulated conductors (“noodles”); This design is most common due to its lowest cost. The twisted veins constantly change their position: some go inward from the surface, others, on the contrary, go from the center to the surface. Since the distribution of current density across the cross-section of the conductor does not change to remain near the surface of the cable, the current passes through the interface from one conductor to another. It happens that the contact between individual cores is not always good (on the surface of each core there is a layer of oxides that conduct current poorly), and numerous transitions through resistance barriers can theoretically affect the transmitted signal. If you cut an old network cable in rubber insulation, a dark film of oxides attracts attention. Such a wire cannot be soldered without stripping; the ohmmeter shows a fairly high resistance...

To reduce the influence of the skin effect, each thin core is sometimes equipped with its own insulation, however, such cables are low-tech, since it is difficult to automate the process of cutting the cores of such a cable.

Speaker cables are characterized by a wide variety of designs, differing not only in their internal structure, but also in their external features: round in cross-section, flat, like thin ribbons, single, double, quad, etc. Despite their high cost, flat wires are very popular in home theater installations because they are easily hidden under wallpaper, carpets, etc. Double wires in pairs are in demand, which are convenient for connecting acoustics using Bi-Wiring and Bi-Amping schemes.

A variety of speakers are home theater speakers, which have specific requirements. They will be discussed in a separate brochure.

Dedicated to the acoustics of a room, we found out that any room is a kind of resonator that dramatically affects the sound character of the system. Now it’s time to talk directly about the sources of this very sound, that is, about speaker systems.

In order to properly understand the processes occurring in a box on the wall of which one or more speakers are mounted, you need to thoughtfully read a couple of books, each of which contains more formulas than the entire school physics course. I won’t go into such depths, so this material is not worth it as a comprehensive analysis or guide to building audiophile speakers. However, I really hope that it will help beginning music lovers (and some chronic ones too) to properly navigate the variety of acoustic solutions, each of which its developers, of course, call the only correct one.

For some time after the invention of the electrodynamic emitter with a conical diffuser (okay, just dynamics) in 1924, its wooden frame served primarily decorative and protective functions. This is understandable - after many years of listening to records through mica membranes and gramophone bells, the sound of the new device, even without any acoustic modifications, seemed simply the apotheosis of euphony.

However, recording technologies quickly improved and it became clear that it was extremely problematic to more or less plausibly reproduce the audible range with a speaker simply mounted on some kind of stand. The fact is that the dynamic head, left to its own devices, is in a state of acoustic short circuit. That is, the waves from the front and rear surfaces of the diffuser, emitted, of course, in antiphase, seamlessly overlap each other, which most sadly affects the efficiency of operation, and primarily on the transmission of bass.

By the way, in the course of this story I will most often talk about low frequencies, since their reproduction is a key point in the operation of any speaker cabinet. Due to the short length of the emitted waves, HF drivers do not need to interact with the internal volume of the speaker at all, and are most often completely isolated from it.

Soul wide open

The easiest way to separate the front radiation of a speaker from the rear is to mount it on a shield as large as possible. From this simple idea, the first acoustic systems were born, which were a box with an open back wall, since for compactness the edges of the shield were simply taken and bent at a right angle. However, in terms of bass reproduction, the success of such designs was not very impressive. In addition to the imperfection of the body, the problem was also in the suspension travel of the diffusers, which was very small by modern standards. To somehow get out of the situation, speakers were used as large as possible, capable of developing acceptable sound pressure with a small vibration amplitude.

Despite the seeming primitiveness of such designs, they also had some advantages, and they were so specific and interesting that adherents of open speakers have not died out to this day.

To begin with, the absence of any obstacles in the path of sound waves - the best way to increase sensitivity. This point is especially valuable for audiophile tube amplifiers, especially single-ended ones or those without feedback. Large-diameter paper diffusers, even at a power of about four to five watts, are capable of creating a rather impressive, and at the same time surprisingly open and free sound.

As for the rear radiation, in order not to introduce distortion into the direct sound, it must arrive to the listener with a noticeable delay (over 12-15 ms) - in this case, its influence is felt as a slight reverberation, only adding air to the sound and expanding the musical space . The subtlety is that to create this very “noticeable delay”, the speakers, of course, must be located at a fair distance from the walls. In addition, the large area of ​​the front panel and the impressive size of the low-frequency drivers have a corresponding impact on the overall dimensions of the speakers. In a word, owners of small and even medium-sized living rooms, please do not worry.

By the way, a special case open systems- acoustics built on electrostatic emitters. Only due to the almost weightless diaphragm of a large area, in addition to all the advantages described above, electrostats add the ability to delicately transmit even the sharpest dynamic contrasts, and due to the lack of signal separation in the midrange and treble zones, they also have enviable timbral accuracy.

Open design

Pros: High-end open-back speakers are a great way to get a real kick out of listening to purist tube single-ended speakers.

Minuses: It’s better to forget about fat compression bass right away. The entire sound path must be subordinated to the idea of ​​open acoustics, and the speakers themselves will have to be chosen from an extremely limited number of proposals.

Locked in a box

With the increase in power and improvement in amplifier parameters, the ultra-high sensitivity of acoustics has ceased to be the main stumbling block, but the problems of uneven frequency response, and especially the correct reproduction of bass, have become even more pressing.

A giant step towards progress in this direction was made in 1954 by the American engineer Edgar Vilchur. He patented a closed-type speaker system, and it was by no means a gimmick in the style of today's patent trolls.

By that time, the bass reflex had already been invented and, of course, a speaker was also tried on a box with a bottom more than once, but nothing good came of it. Due to the elasticity of the enclosed volume of air, it was necessary either to lose a significant part of the energy of the diffuser, or to make the body prohibitively large in order to reduce the pressure gradient. Vilchur decided to turn evil into good. He greatly reduced the elasticity of the suspension, thus transferring control of the movement of the diffuser to the volume of air - a spring that is much more linear and stable than a corrugation or rubber ring.

In this way, it was possible not only to completely get rid of the acoustic short circuit and increase the output at low frequencies, but also to significantly smooth out the frequency response throughout its entire length. However, a minor point also emerged. It turned out that damping with a closed volume of air leads to an increase in the resonant frequency of the moving system and a sharp deterioration in the reproduction of frequencies below this threshold. To combat this problem, it was necessary to increase the mass of the diffuser, which logically led to a decrease in sensitivity. Plus, the absorption of almost half of the acoustic energy inside the “black box” could not but contribute to the reduction in sound pressure. In a word, the new type of speakers required amplifiers of quite serious power. Fortunately, at that time they already existed.

Today, closed design is used mostly in subwoofers, especially in those that claim serious musical performance. The fact is that for home theaters, energetic development of the lowest bass is often more important than dynamic and phase accuracy throughout the low-frequency range. But by combining a relatively compact closed sub with decent satellites, you can achieve a much more correct sound - albeit not filled with super-deep bass, but extremely fast, collected and clear. All of the above can also be attributed to full-range speakers, “closed” models of which occasionally appear on the market.

closed box

Pros: Exemplary attack speed and low-frequency resolution. Relatively compact design.

Minuses: A fairly powerful amplifier is required. Ultra-deep bass on the verge of infrasound is very difficult to achieve.

The case is a pipe

Another way to curb anti-phase rear radiation was the phase inverter, in Russian literally “phase reversal”. Most often it is a hollow tube mounted on the front or rear surface of the housing. The principle of operation is clear from the name and is simple: since it is difficult and irrational to get rid of radiation from the back side of the diffuser, it means that it needs to be synchronized in phase with the front waves and used for the benefit of listeners.

In fact, a pipe with air is an independent oscillatory system that receives impulse from the movement of air inside the housing. Possessing a very specific resonance frequency, the bass reflex works more efficiently the closer the diffuser oscillations are to its tuning frequency. Sound waves of higher frequencies simply do not have time to move the air in the pipe, and although lower frequencies do, the lower they are, the more the phase of the bass reflex radiation shifts, and, accordingly, its efficiency. When the phase rotation reaches 180 degrees, the tunnel begins to frankly and very effectively muffle the sound of the bass driver. This is what explains the very steep drop in speaker sound pressure below the bass reflex tuning frequency - 24 dB/oct.

In a closed box, by the way, at frequencies below the resonant frequency response decay is much smoother - 12 dB/oct. However, unlike a blank box, a box with a pipe in the side wall does not force designers to go to any lengths to minimize the resonant frequency of the speaker itself, which is quite troublesome and expensive. Setting up a bass reflex tunnel is much easier - just select its internal volume. This is, however, in theory. In practice, as always, unforeseen difficulties arise, for example, at high volume levels, the air exiting the hole can make a noise almost like the wind in a stove chimney. In addition, the inertia of the system often causes a drop in attack speed and deterioration of articulation in the bass. In a word, the scope for experimentation and optimization before the designers of bass reflex systems is simply incredible.

Phase inverter

Pros: Energetic response to low frequencies, the ability to reproduce the deepest bass, relative simplicity and low cost of production (with considerable complexity of calculation).

Minuses: In most implementations it is inferior to a closed box in terms of attack speed and clarity of articulation.

Let's do without a reel

Attempts to get rid of the genetic problems of the bass reflex, and at the same time save on the volume of the cabinet without compromising the depth of the bass, gave the developers the idea of ​​​​replacing the hollow pipe with a membrane driven by vibrations of the same working volume of air. Simply put, another low-frequency driver was installed in a closed box, only without a magnet and voice coil.

The design was called “passive radiator”, which is often not very correctly translated from English as “passive radiator”. Unlike a subwoofer pipe, a passive diffuser takes up much less space in the case, is not so critical to the location, and besides, like the air inside a closed box, it dampens the leading driver, smoothing its frequency response.

Another plus is that with an increase in the area of ​​the radiating surface, to achieve the desired sound pressure, a smaller amplitude of vibrations is required, which means that the consequences of nonlinear operation of the suspension are reduced. Both diffusers vibrate in phase, and the resonant frequency of the free membrane is adjusted by precise adjustment of the mass - a weight is simply glued to it.

Passive radiator

Pros: Compact design with impressive bass depth. Lack of bass-reflex overtones.

Minuses: An increase in the mass of emitting elements leads to an increase in transient distortions and a slower impulse response.

Exit from the maze

Acoustics, armed with bass reflexes and passive radiators, reproduce deep bass thanks to resonators operating through the mediation of air inside the speakers. However, who said that the volume of the speaker cannot play the role of a low-frequency emitter in itself? Of course it can, and the corresponding design is called an acoustic labyrinth. In essence, it is a waveguide with a length of half or a quarter of the wavelength at which it is planned to achieve resonance of the system. In other words, the design is adjusted along the lower boundary frequency range AS. Of course, using a full-wavelength waveguide would be even more efficient, but then for a frequency of, say, 30 Hz, it would have to be made 11 meters long.

In order to fit even a structure twice as compact into a column of reasonable dimensions, partitions are installed in the housing to form the most compact curved waveguide, with a cross section approximately equal to the area of ​​the diffuser.

The labyrinth differs from the bass reflex primarily in its less “resonant” (that is, not accentuated at a certain frequency) sound. The relatively low speed and laminarity of air movement in a wide waveguide prevents the occurrence of turbulence, which, as we remember, generates unwanted overtones. In addition, in this case the driver is free from compression, which increases the resonant frequency, because its rear radiation encounters virtually no obstacles.

There is an opinion that acoustic labyrinths create fewer problems with standing waves in the room. However, with the slightest miscalculations in development or manufacturing, standing waves can arise in the waveguide itself, which, unlike a bass reflex, has a much more complex structure of resonances.

In general, it must be said that competent calculation and fine-tuning of an acoustic labyrinth are very difficult and labor-intensive processes. Exactly because of this reason this type cases are found infrequently, and only in speakers of a very serious price level.

Acoustic labyrinth

Pros: Not only good response, but also high tonal accuracy of the bass.

Minuses: Serious dimensions, very high complexity (read - cost) of creating a properly functioning structure.

Hey, on the ferry!

The horn is the oldest and, perhaps, the most provocative type of acoustic design. It looks cool, if not shocking, it sounds bright, and at times... In old films, characters sometimes shout something into each other's mouthpieces, and the characteristic coloring of such a sound has long become a meme in both the music and film worlds.

Of course, today's acoustics have moved very far from the tin funnel with a handle, but the principle of operation is still the same - the horn increases the air resistance for better coordination with the relatively high mechanical resistance of the moving speaker system. Thus, its efficiency increases, and at the same time a clear directionality of radiation is formed. Unlike all previously described designs, the horn is most often used in high-frequency speaker sections. The reason is simple - its cross-section increases exponentially, and the lower the reproduced frequency, the larger the size of the output hole should be - already at 60 Hz a bell with a diameter of 1.8 m will be required. It is clear that such monstrous designs are more suitable for stadium concerts, where they really can be found periodically.

The main trump card of adherents of horn playback is that acoustic amplification allows, for a given sound output, to reduce the membrane stroke, and therefore increase sensitivity and improve musical resolution. Yes, yes, again a nod to the owners of single-ended tube circuits. In addition, with proper calculation, bells can play the role of acoustic filters, abruptly cutting off sound outside their band and allowing you to limit yourself to the simplest, and therefore introduce minimal distortion, electric crossovers, and sometimes even do without them.

Skeptics never tire of reminding us of the characteristic horn coloring, which is especially noticeable on vocals and gives it a characteristic nasal quality. It’s really not easy to overcome this problem, although judging by the way the best examples of High-End horns play, it’s quite possible.

Horn

Pros: High acoustic efficiency, which means excellent sensitivity and good musical resolution of the system.

Minuses: Characteristic, difficult-to-remove sound coloration, non-childish sizes of mid- and especially low-frequency structures.

Circles on the water

It is with this analogy that it is easiest to describe the nature of the radiation of counter-aperture acoustic systems, first developed in the Soviet Union in the 80s of the last century. The principle of operation is non-trivial: a pair of identical speakers are mounted so that their diffusers are located opposite each other in a horizontal plane and move symmetrically, either compressing or decompressing the air layer. As a result, annular air waves are created that diverge evenly in all directions. Moreover, the characteristics of these waves during their propagation are minimally distorted, and their energy decays slowly - in proportion to the distance, and not its square, as in the case of conventional speakers.

In addition to long-range and omnidirectionality, counter-aperture systems are interesting due to their surprisingly wide vertical dispersion (about 30 degrees versus standard 4-8 degrees), as well as the absence of the Doppler effect. For speakers, it manifests itself in signal beats caused by a constant change in the distance from the sound source to the listener due to vibrations of the diffuser. True, the actual audibility of these distortions still causes a lot of controversy.

The mutual penetration of the concentric sound fields of the right and left speakers creates a very wide and uniform zone of surround perception, that is, in essence, the issue of precise positioning of the speakers relative to the listener becomes irrelevant.

A characteristic feature of counter-aperture is that the sound coming to the listener from virtually all directions, although it creates an impressive presence effect, cannot fully convey information about the sound stage. Hence the stories of listeners about the feeling of a piano flying around the room and other wonders of virtual spaces.

Contraperture

Pros: A wide zone of spectacular surround perception, naturalistic timbres due to the non-trivial use of wave acoustic effects.

Minuses: The acoustic space differs noticeably from the sound stage conceived when recording a phonogram.

And others...

If you think that this list of speaker design options is exhausted, then you greatly underestimate the design enthusiasm of electroacoustics. I described only the most popular solutions, leaving behind the scenes a close relative of the labyrinth - a transmission line, a bandpass resonator, a case with an acoustic impedance panel, load pipes ...

Such exoticism is quite rare, but sometimes it materializes in a design with a truly unique sound. And sometimes not. The main thing is not to forget that masterpieces, like mediocrity, are found in all designs, no matter what the ideologists of a particular brand say.

Prepared based on materials from the magazine "Stereo & Video", June 2016.

Nowadays, the computer, both personal and portable laptop, occupies one of the leading places in comparison with the technology that surrounds us in everyday life. We need a computer not only for work, but for a pleasant pastime. Each person has his own set of priorities, but even the most scrupulous scientist and connoisseur, when writing his next dissertation or scientific article, will not mind listening to his favorite music or watching a documentary on the computer, but everyone knows that this is not possible if on your personal There are no speakers on the computer.

So, before buying a new computer or components for it, everyone is faced with the difficult question of how to choose and configure the right speakers for your computer. Nowadays, working on a computer without a headset, namely without speakers, is practically impossible. Speakers are necessary on a computer for watching your favorite movies or listening to music, as well as for communication. Speakers are most often purchased for home leisure, and not for office work, because we rather need them for entertainment than for work. Headphones can serve as an excellent replacement for speakers; you can also use them to watch movies and listen to music, as well as communicate, but in some situations they cannot replace the brilliant acoustics that speakers give us, especially if you are watching a movie not alone, but in company of friends or family. So, when purchasing speakers for your computer, you should remember some rules.

When choosing speakers, you need to decide for what purpose you need them, since the acoustic sound of the speakers will directly depend on this. If, when purchasing speakers, you do not need strong acoustic sound, and you do not plan to listen to music loudly, then in this case, simple and not very expensive speakers will suit you. For connoisseurs of loud music and admirers of excellent sound, it is necessary to choose speakers with a good acoustic system, but the price of such pleasure will be high.

Computer speakers, in comparison with other types of various speakers, are distinguished by their compact size, as well as their ability to suppress magnetic radiation.

Computer speakers can be active or passive. Active speakers are speakers with a built-in amplifier. And passive speakers require additional power during operation, as well as the connection of an amplifier. Passive speakers, unlike active speakers, cost much less, but they sound worse.

Speaker material

When purchasing speakers for your computer, you should pay significant attention to the material of the case, because the sound of the speakers can directly depend on this.

Plastic

Speakers whose housing is made of plastic will cost much less. Unfortunately, although such speakers are cheaper, the sound they produce is not of very high quality. But rather distorted. When the sound is loud, the plastic of the case can vibrate and rattle, which is why the sound is not of good quality.

Tree

Material such as wood for making speaker housings is one of the best materials. Wood transmits sound very well, but is very expensive, so speakers made from wood are not that rare, they can simply be found in a professional speaker system. Manufacturers of computer speakers have resorted to a certain trick and began to make cases from chipboard, MDF or plywood sheets, so they become more affordable in price. When purchasing speakers, you should carefully inspect them; there should be no extra holes in them, they should be completely sealed, this can significantly worsen the sound of the speakers.

The material of the speakers can affect the sound quality only to a minimum, and the main criterion for choosing speakers should be high-quality speakers, as well as good and high-quality assembly of all elements of the speaker.

Main characteristics of the speakers

The most important characteristics when purchasing speakers are their power and sound frequency. However, you should not forget that power and volume are two completely different concepts. The volume of computer speakers can be determined by their sensitivity.

Speaker power

The power of any speakers, be they computer or others, is often called the final and highest point of sound. This speaker value usually shows the highest level of sound at which it is produced without distortion. The final power figures may vary; this value will depend on the room in which the computer speakers are installed and in which direction they are directed. For an ordinary apartment, a maximum of 50 W of speaker power will be sufficient, no more, or even less.

The acoustic frequency range represents the frequency band that the system can and does reproduce. Human hearing is capable of perceiving a frequency range ranging from 20 to 20 thousand Hz. Only professional and expensive acoustic systems can transmit a high-quality and pleasant to the ear range. Speaking of speakers for the computer that we use in everyday life, the sound range on them should be 40 Hz-18 kHz, this range will transmit the sound as efficiently as possible. Outside this sound range, computer speakers will not only transmit poor-quality sound, but also distort the sound, and it may also vibrate, crackle or hiss. Therefore, when buying speakers, you should pay attention to the sound range that is indicated on this headset; if not very expensive speakers have a range ranging from 20 Hz-20 kHz, then this will most likely turn out to be a hoax and you should not purchase such speakers.

Satellites and subwoofers

Before purchasing speakers for your computer, you should understand their types. A satellite is a small speaker, most often no more than 20 cm in height, and it is also capable of transmitting medium and high frequencies. Satellites are very popular for a laptop set, as well as a personal computer; such small speakers are easy to move, take with you on the road, or install in any accessible place, on a table. Often a subwoofer is included with two satellite speakers. A subwoofer is a large speaker, compared to satellites; in most cases it is placed on the floor under a computer desk. The subwoofer is capable of reproducing low frequencies and transmitting loud sound.

• Before directly connecting the speakers to your computer, you should install audio drivers on it (if they have not been downloaded and installed previously on your computer). To install drivers, you should take a disk (it is usually included when purchasing a computer) and install the program. After installing a special program, you should reboot the computer, and then you should start adjusting the sound accordingly.

• Direct connection of speakers. At the back of the computer (in most cases), find the colored holes for the plugs, into these holes according to the color scheme and connect the plugs from the speaker wires. If the speakers are connected correctly, a window will open on the computer desktop with which you will need to select a program, namely “front speakers” or “rear speakers”.
• If your speaker system has a subwoofer and small speakers (satellites), then only one subwoofer is connected to the computer using one wire, and the speakers themselves are connected to the computer through the subwoofer. After connecting the subwoofer to a personal computer, an analog window will appear on the desktop, prompting you to select a command, namely “line output”. Check the box next to this program and then save the settings.
• If you have made the connection as described earlier, and the speakers do not produce sound. In this situation, open the sound settings and set all available sliders to the maximum value; there are situations when any slider can block the sound of the speakers.

Anyone can install and connect speakers to a computer, even those who do not understand anything about this type of technology; the most important rule is to connect all the wires correctly (do not confuse their colors). When installing speakers, it is very important to choose the right place for their installation, because the acoustic sound will directly depend on this.

Place for installing the speaker

To position the speakers, you need to choose the right place where the sound from the speakers will be most pleasant to listen to. The favorable distance that should be between two or more speakers on a computer should be at least 1.5 meters or even more. If the speakers are located close to each other, their sound will be blurred and thus the result will be poor quality sound. It is recommended to place the speakers on a table or other devices, but not on the floor; the floor can muffle and distort their sound, this does not apply to the subwoofer. The ideal height of speakers from the floor is considered to be from 1 to 2 meters. As for the subwoofer, its best sound will be heard if it is placed on the floor, because it is known that low frequencies are well perceived on a perfectly flat and hard surface.

It's hard to imagine now Personal Computer without speakers. Many are even surprised if the computer is without them. In this case, watching movies, listening to music and playing games is simply not possible. Therefore, when purchasing a computer, everyone tries to immediately buy all the necessary components, incl. columns.

It is worth noting that computer speakers do not produce high-quality sound. Therefore, for those who value high-quality sound while watching a movie or listening to music, it is recommended to immediately purchase stereo systems for a home theater. Computer speakers are more suitable for people for whom sound quality is not a priority. But even in this case, choosing good speakers is not an easy task. They must be small in size, suppress magnetic radiation, have special connectors and be compatible with the computer's sound card.

Types of computer speakers

There are active and passive speakers. Active speakers have a built-in amplifier. Passive speakers are used for laptops and require an amplifier and additional power. For passive speakers bad sound and low cost. Therefore, they lose to active speakers that provide high-quality sound.

Columns are distinguished by configuration. In this case they can be 2.0, 2.1, 4.1, 5.1 and 7.1. The simplest speakers of modification 2.0. They have two speakers and no additional devices or amplifiers. Speakers from other modifications have more parts, as well as a subwoofer.

Speakers 2.0 and 2.1 are mid-priced and designed for listening to music, videos and games. They are quite sufficient for home or office use. May have one or more speakers. The 2.1 modification speakers have a subwoofer, which is responsible for outputting low frequencies, while the speakers are responsible for outputting high and medium frequencies. In this case, the sound becomes more voluminous and realistic.

5.1 and 7.1 speakers allow you to fully immerse yourself in the gameplay or watching a movie. They have multiple channels and the sound quality is much better than the two previous configurations. But here it is very important that the speakers fit the sound card the computer itself. 5.1 and 7.1 modification speakers allow you to create a home theater.

The 5.1 modification has two front, two rear, one center speaker and a subwoofer. Modification 7.1 resembles 5.1, but only supplemented with two more rear speakers.

What to look for when choosing speakers?

When choosing speakers, you should always pay attention to the material of manufacture. The sound quality largely depends on the material. Plastic speakers reduce sound quality and are cheap. From such speakers you can only expect rattling, poor sound reproduction and many other troubles. Wooden speakers, on the contrary, allow you to create high-quality sound and good acoustic properties. But here you may encounter the high cost of speakers. Solid wood speakers are produced only for professional use. For other cases, wood is replaced with chipboard, MDF and multi-layer plywood. Speakers made of any material should not have any holes, because they degrade the sound. The exception is the bass reflex, which has holes on the front side for bass playback.

But still, the material is not the main characteristic of high-quality sound. It is necessary to pay attention to speakers, amplifiers, filters, build quality and speaker system settings.

Before we start reviewing specifications, which you need to pay attention to when choosing speakers, it is worth noting that many consider power and volume to be the same indicator. This is a misleading opinion. Power affects acoustics, and volume is related to sensitivity. Sound volume parameters should not be higher than 85 decibels.

Now let's talk more about the technical characteristics.

Power

There are two types of power - peak music power (P.M.R.O - Peak Music Power Output) and root mean square power (RMS - Root Mean Square). When choosing, you should pay attention to the second type of power. It is she who characterizes maximum power, in which the speaker system can reproduce sounds for a long time without distortion or damage. With this power, comfortable and high-quality music reproduction occurs. Peak musical power can be several times higher than the second power.

For a computer that does not have special requirements and will be placed in an average-sized room, it is enough to have a power of 20-50 watts.

Speaker range frequency

This parameter refers to the frequency that the speakers are capable of reproducing. Ideal Frequency playback range is 20-20000 Hz, but they are only found in professional acoustic systems. In ordinary columns, the characteristics often indicate a frequency from 40 Hz to 18 kHz. In principle, this is enough for a person to normally perceive high-quality sound. If the frequency is lower or higher than the specified parameter, the sound will be accompanied by crackling, hissing, dip and distortion. In addition, it is worth considering that a cheap speaker system cannot have a frequency of 20-20,000 Hz. This is not true.

Sensitivity

This parameter, which directly affects the sound volume and indicates the level of sound reproduction at a distance of one meter at a power of 1 W. The indicator is measured in decibels. The optimal option is considered to be a sensitivity of 85-89 decibels.

If you purchase speakers that have different sensitivity, then best sound will come from a speaker with greater sensitivity.

Number of lanes

This parameter characterizes the number of speakers. Single-way speaker systems have one speaker. A two-way speaker consists of two speakers, where one speaker reproduces low-frequency sounds, and the second one reproduces mid- and high-frequency sounds. Three-way speakers have three speakers. The first speaker produces low sounds, the second - mid-range sounds, and the third - high-pitched sounds.

There are speaker systems with more than three bands. In this case, the sounds are more colorful.

Size

For many, this parameter may not play a role during selection. But, if, after all, the speakers should not attract attention, then you should choose a size so that you can hide them. The best option is speakers measuring 10.4x16.5x15 cm. They can be hidden behind the computer.

Control

The control panel (basically the volume control) is located either on the subwoofer or on one of the speakers. On the column it can be on the side, front or back. It is best to control the speakers from a computer. Frequent use of the volume control leads to its erasure and failure.

Modern speakers have wired or remote controls

How to choose speakers?

When buying speakers, it's worth doing a little test. Turn on the speakers and gradually increase the volume. Stop at the moment when the sound begins to distort. Listen to the sound and determine if it is enough for you to listen to music, watch a movie or play games.

Additional functions

An excellent addition to the speakers would be the presence of a headphone output, a control panel, an information display, a function for playing radio or music from a memory card or flash drive.

Speaker Manufacturers

Speakers are produced by a fairly large number of companies. Therefore, we will focus on the most popular companies that are in demand among buyers.

Creative, Defender, Edifier, F&D, Logitech, Microlab and Sven companies produce high-quality speaker systems. The speakers are not cheap, but the sound quality is worth the money.

Cheaper options for speakers that are in demand among users are presented by A4Tech, Acme, Codegen, Gembird, Gemix, Genius. But, unfortunately, the sound is quite bad.

Acoustic systems for laptops are produced by A4Tech, Defender, Divoom, HQ-Tech, Jabra, Philips, Sanyoo, Sony, Speed-Link.

Price

The cost of the speakers depends on the modification. The cheapest speakers are modifications 2.0 and 2.1. They cost from $10 to $50. The 5.1 and 7.1 modification acoustic system costs over $70.

Where to buy speakers?

You can purchase speakers at an electronics store or online stores. But before you make a purchase, you should decide on the parameters that the speakers should have and the brand, and also not rush into the purchase.

How to use speakers?

Using the speakers is quite simple. First they need to be connected to the computer. After that, turn on the sound and adjust the volume. Next, choose your favorite music or movie and enjoy.