The name of the speakers. Simple options for choosing speakers in the car so that the speakers sound

coaxial heads. This is an all-in-one solution, the design is based on a large woofer-midrange speaker (responsible for reproducing the largest frequency range), above the diffuser of which, with the help of a bracket or stand, which is a continuation of the magnet core, a tweeter head (“tweeter”) is installed. This design allows you to save space, greatly simplifies the installation of acoustics (since you need to install only two speakers), but it does not always allow you to achieve high sound quality.

Component acoustics. This is a professional solution, and therefore more complex and expensive. In this case, several speakers are used, usually a set of woofer-midrange speakers and “tweeters” separate from them. Also, a set of component acoustics often provides passive (rarely active) filters, or crossovers - devices that separate the audio signal into low-midrange and high-frequency components, which are reproduced by separate heads. Component acoustics allows you to achieve the highest quality sound, but it is expensive, and the installation of such an audio system is much more difficult than installing coaxial heads.

Classification of acoustic systems

All dynamic heads can also be classified according to various criteria.

By size

Today, the most widely used speakers are three main sizes (calibers):

• 4 inches (10 cm);
• 5.25 inches (13 cm);
• 6.5-7 inches (16.5-17 cm).

Speakers of other calibers have some distribution, in particular, heads with a diameter of 8 inches or more are used in subwoofers, and all high-frequency heads in component acoustics have a caliber of 1-2 inches.

By shape

There are two main forms of dynamics:

• round;
• Elliptical.

Round heads are traditionally used in component speakers, and elliptical designs are most often (but not always) found in coaxial speakers. Elliptical loudspeakers are great for installation in trunk shelves, using their area with maximum efficiency.

According to diffuser material

Diffusers for automotive heads (and not only automotive ones) are made from six basic types of materials:

• Paper or pressed cardboard- a classic version that still remains relevant due to the unsurpassed ability of paper to reproduce sound of maximum quality and reliability. Now paper diffusers have a variety of impregnation, which improves their quality and resistance to negative environmental influences (primarily humidity);
• fiberglass- a modern version, relatively inexpensive and providing acceptable sound characteristics, a definite plus - excellent appearance;
• Kevlar- material of the same level as fiberglass, but has a much higher strength and cost;
• Polypropylene- an inexpensive, simple and high-quality solution, a diffuser made of this plastic is light and durable. In addition, it has excellent decorative qualities. Polypropylene has become very widespread today, especially in inexpensive heads;
• Silk- it is used exclusively in dome tweeters ("tweeters"), to achieve the necessary rigidity, silk is impregnated with various compositions;
• Aluminum- this material, compared to others, is used quite rarely and has an above average price. A metal diffuser allows you to achieve maximum playback quality, as it introduces a minimum of distortion, but it has a number of drawbacks that, with an illiterate approach to building a car speaker, can have the most negative impact on sound quality.

As already mentioned, today the most common are speakers with paper and polypropylene cones, diffusers made of fiberglass and aluminum are widely used. Heads with a Kevlar cone are rather exotic, which makes it possible to build a car audio system with excellent performance, but at a significant cost.

Type of diffuser suspension

Today, the diffuser is attached to the diffuser holder using natural rubber hangers, various rubberized fabrics, polyurethane foam, etc. The shape of the suspensions can be semi-toroidal (that is, it looks like a rubber torus cut lengthwise into two halves), “S”-shaped and more complex shapes.

Other articles

October 15

Feeling the breath of winter, all motorists are thinking about replacing seasonal tires. And so many of us, when buying winter tires, face a difficult choice - “studded” or “Velcro”? Each type of tire has its own advantages and disadvantages, and it can be very difficult to give preference to one. In this article, we will try to make this difficult choice.

October 14

Filling the tank with low-quality diesel fuel can harm the engine up to its complete failure. To minimize or eliminate the negative consequences of refueling with low-quality diesel, special auto chemicals help - additives in diesel fuel, which are described in detail in this article.

13 October

Twice a year, all drivers ask one question - when to replace seasonal tires? In the spring, everyone is wondering when to put on summer tires, and in the fall they are looking for the moment when to install winter tires, and very often drivers make a mistake. Read this article to learn how to choose the best time to replace seasonal tires, and how not to make a mistake in this difficult matter.

First of all, let's deal with the terms, since the terms "loudspeaker", "column", "speaker", "acoustic system" are often used at random, creating a fair amount of confusion.

Speaker - this is a device designed to effectively emit sound into the surrounding space in the air, containing one or more loudspeaker heads in the presence of acoustic design and electrical devices (filters, regulators, etc.).

In domestic technical literature, an erroneous practice has developed, according to which the term "loudspeaker" (SH) 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 should be designated as loudspeaker head .

The term is often used for a set of Hi-Fi and Hi-End loudspeakers. acoustic system (AC) (acoustical system or loudspeaker system). Acoustic system includes acoustic speakers .

Depending on the purpose, speakers differ significantly in parameters, design and design. The main types of acoustic systems on the modern market can be conditionally 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 such as "Home Theater" (Home-Theatre);
• for modern computer systems(AC Multi-Media), etc.;
• Speakers for sound systems and sound amplification, including for conference systems and speech translation systems (these, in particular, include ceiling speakers);
• concert and theater speakers;
• studio speakers;
• automotive (and generally transport) speakers;
• Speakers for private listening (stereo headphones).

AC device

AS can be single-lane And multi-band . Single-band speakers are used, as a rule, in mass equipment of the budget sector. High-quality speakers (Fig. 1) use a multi-band construction principle, since the use of a single wide-range speaker head does not provide high sound quality.

AS usually consists of:

• loudspeaker heads, each of which (or several at the same time) operate in its own frequency range;
• corps;
• filtering and corrective circuits, as well as other electronic devices (for example, for overload protection, level indication, etc.);
• audio cables and input terminals;
• amplifiers for active acoustic systems and crossovers (active filters).

Rice. 1. Speaker system Defender

Speaker heads

Loudspeaker heads are classified according to the principle of operation, according to the method of radiation, according to the band of transmitted frequencies, according to the field of application, etc.

According to the principle of action , i.e. according to the method of converting electrical energy into acoustic, loudspeakers are divided into electrodynamic, electrostatic, piezoceramic (piezofilm), plasma, etc.

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

Rice. 2. Electrodynamic reel-to-reel loudspeaker

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

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

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

Rice. 3. Ribbon speaker

Ribbon loudspeakers (Fig. 3) use a thin metal ribbon 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 efficient 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 a full sweep 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 obtain 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 ... 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 action of which the membrane vibrates and emits sound, is applied to the fixed electrodes. Loudspeakers of this type provide purity and transparency of sound due to low levels of transient distortion.

Rice. 5. Lineup of electrostatic loudspeakers Final

Rice. 6. Central loudspeaker electrostatic speaker. Model 200

On fig. 5 shown the lineup final electrostatic loudspeakers, and in fig. 6 - close-up of the center speaker.

Rice. 7. Piezo-film loudspeaker

Piezoceramic (piezofilm) 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) of piezoceramics (titanium zirconate, barium titanate, etc.). The bimorph element is fixed on both sides; when an electrical signal is applied, bending deformations occur in it, which are transmitted to the diaphragm (2) connected to it. A variation of this type of loudspeakers are piezo-film radiators, they use high-polymer films, which, using a specially developed technology, are given piezoelectric properties (when they are polarized in a strong magnetic field). If such a film is given the shape of a dome or cylinder, then under the action 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, the 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 has a pre-horn chamber, then it is called a narrow-mouth horn, and if only a horn is used, then it is a wide-mouth horn.

Rice. 8. Horn loudspeaker

Horn loudspeakers are widely used in the creation of sound systems for streets, stadiums, squares, sound amplification systems in various rooms, high-quality household systems, warning systems, etc.

The reasons for the spread of horn loudspeakers are primarily due 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 makes it possible to form a given directivity characteristic, which is very important when designing sound amplification systems. However, when using horn loudspeakers, there are problems associated with 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 non-linear distortions.

The design of the loudspeaker heads depends on the frequency band in which they must operate. On this basis, speakers are divided into:

• broadband (OO "full-range");
• low-frequency (reproducible range of 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 is usually low frequency GG, therefore, they must perceive loads 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. Diaphragms of modern low-frequency GGs are made from complex compositions based on natural long-fiber cellulose with various additives. Sometimes the composition of 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 being used.

Rice. 9. Woofer

Home theater speakers (especially center and front channels, as well as a subwoofer) require the use of carefully shielded low frequencies.

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

Tweeters (HF GG). (Fig. 10). Requirements for them last years increased sharply due to the increase spectral density power in the high-frequency part of the spectrum in modern electronic music, the expansion of the frequency and dynamic range of programs reproduced by digital sound reproducing 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 provide equivalent high-quality sound reproduction in such a wide range using one GG. Therefore, most of the HF GGs currently produced 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 loudspeakers are typically electrodynamic cone loudspeakers enclosed in plastic or metal enclosures. They are used for scoring rooms and in emergency warning systems of buildings. Due to the large opening angle of the sound pattern and the wide range of reproducible frequencies, the ceiling speakers are capable of reproducing sound quite well, in addition, they harmoniously fit into almost any interior.

Ceiling loudspeakers provide a more even distribution of sound throughout the room compared to other loudspeakers and do not require the installation of powerful amplifiers. Their use is especially effective for scoring 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, skids or brackets. Many loudspeakers are attached to ceiling tiles with screws. Unlike "conventional" PA systems, ceiling speaker systems are high voltage, typically 100V line voltage, 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 (Fig. 11) is based on the required sound pressure level at the level of the listeners' ears (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 carried out according to approximate formulas. Table 1 shows the number of ceiling speakers for a given ceiling height and room area, which gives best quality sound and the most uniform distribution of sound waves.

Rice. 11. Ceiling speaker layout

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

S \u003d (2x (H - 1.5 m)) 2, where H is the height of the ceiling.

Table 1. To the calculation of the warning system

P	103,5	101	99	97,5	96
P/2	100,5	98	96	94,5	93
H/S	3	3,5	4	4,5	5
25	2	1	1	1	1
35	3	2	1	1	1
50	4	2	1	1	1
80	6	3	2	2	1
100	7	4	3	2	2
150	10	6	4	3	2
200	13	8	5	4	3
300	20	11	7	5	4
400	26	15	10	7	5
500	33	19	12	8	6
600	40	22	14	10	8
700	46	26	17	12	9
800	53	30	19	13	10
900	59	33	22	15	11
1000	66	37	24	17	12

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

Ceiling speakers are not recommended for ceiling heights greater than 5 meters. However, if ceiling speakers are to be used, care must be taken to improve sound distribution and reduce reverberation (echo). If the ceiling speakers are placed too close together, the sound will be distributed unevenly at the level of the listeners' ears. 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 loudspeakers in this case entails an increase in reverberation, especially in rooms decorated with glass, marble, etc. Reverberation can be reduced by using sound-absorbing materials such as carpets, tapestries, curtains, etc.

On fig. Figures 12 and 13 show examples of Kramer Electronics in-ceiling and in-ceiling loudspeakers.

Speaker box. The main types of buildings and their purpose

The speaker cabinet performs a variety of functions. In the bass region, it blocks the effect of "acoustic short circuit", which occurs due to the addition of the 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 the housing allows to increase the radiation intensity at low frequencies, as well as to increase the mechanical damping of the loudspeakers, which makes it possible to “smooth out” resonances and reduce the unevenness of the amplitude-frequency characteristic. The corpus has a significant impact not only in the area of ​​low, but also in the area of ​​medium and high frequencies. A properly designed and manufactured cabinet has a huge impact on sound quality.

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

Infinite Screen occurs when loudspeakers are installed in the wall of a room with a sufficiently large volume behind it. This loudspeaker setup tends to have a “thumbling” effect at low frequencies because there is no damping.

Closed body. In modern speakers, mostly closed compression-type cases are used. The principle of operation of the 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 she who begins to make the main contribution to the restoring force applied to the diaphragm.

Chassis with phase inverter- 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 resonance frequency region of the oscillatory system, which is formed by the mass of air in the hole or pipe and the mass of air in the housing.

Casings with a phase inverter (Fig. 14 a) have many varieties. The case, using a special pipe inserted into the hole, allows you to reduce the size of the case and adjust the phase inverter by adjusting the size of the pipe (Fig. 14 b).

If a passive (i.e., without a magnetic circuit) loudspeaker is installed in the opening of the housing, 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 cabinet with various options for phase inverters: a - phase inverter; b - phase inverter with a pipe; c - passive radiator

labyrinth is a variant of the case with a phase inverter, in which special partitions are installed. When the length of the labyrinth reaches 1/4 wavelength at the resonance frequency of the subwoofer, it acts like a phase inverter. The use of a labyrinth expands the possibilities for tuning to lower frequencies. Resonances at harmonics from the main resonant frequency of the pipe are damped by sound-absorbing materials on the walls of the case (Fig. 15 a).

Rice. 15. The case of the speaker type of labyrinth (a) and the type of transmission line (b)

transmission line It's a kind of labyrinth. It differs from the labyrinth in that the entire volume of the body is clogged with sound-absorbing material, and the cross section of the line is made variable - more at the cone, less at the hole (Fig. 15 b). Cases of this type are very difficult to set up.

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

Speakers with smoothed corners, streamlined shape, with an asymmetrical arrangement of the GG sound better, however, it is difficult and expensive to manufacture cases of such speakers, so the vast majority of speakers are produced in rectangular cases. To reduce diffraction effects at the corners of the front panel, special measures are taken, including the placement of sound-absorbing materials (“acoustic blanket”), optimization of the ratio of front panel dimensions and case depth, selection of an asymmetrical arrangement of loudspeakers, etc.

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

In modern speakers, the case is a rather complex and expensive structure (Fig. 16). As a criterion for the effectiveness of the measures taken to soundproof the cabinet, it is customary to consider the difference between the sound pressure level emitted by the cabinet walls and the sound pressure level from the speaker system as a whole, it should be at least 20 dB.

Rice. 16. Section AC

In addition to objective measurements, when designing, listening to speakers in cases of various designs is carried out.

Filtering and correcting circuits

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

Most speakers for home use use the so-called. passive filters, which are included between the amplifier and the 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 the first, second, third and fourth order. The slope of the first order filters is 6dB/octave, the second is 12dB/octave, the third is 18dB/octave and the fourth is 24dB/octave.

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

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

Third order filters have good phase characteristics with any connection polarity. On fig. 18 shows the frequency response of the filter of the third order, and in fig. 19 - its electrical circuit.

Rice. 18. Frequency response of the third order filter

Rice. 19. Wiring diagram third order filter

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

In three-band AC, the frequency response of the filter looks like that shown in Fig. 20.

Fourth-order Butterworth filters have high passband roll-off, which dramatically reduces speaker interference in the crossover region. The phase shift is 360 degrees, that is, in practice it is absent. However, the problem is that such filters have a variable phase shift, which can cause unstable operation of the speaker. Linkwitz and Riley succeeded in optimizing the fourth-order filter scheme for AS. Their filter consists of two series-connected second-order Butterworth filters for high-frequency HG and for low-frequency GG. Such a filter has no phase shifts and allows time correction for speakers that do not radiate sound in the same plane. These filters provide the very best acoustic performance.

In "active" speakers with built-in multiband amplifiers, active filters are used, 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 crossover frequency tunability, greater stability of characteristics, etc. However, passive filters provide a greater dynamic range, less noise and non-linear distortion. Their disadvantages include temperature instability, which leads to a change in the shape of the frequency response with an increase in the level of the input signal (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 the filter characteristics can be very sensitive. In recent years, a number of foreign firms have begun to use digital filters in acoustic systems, which provide real-time filtering, correction, and adaptation 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 options for threshold circuits, the response thresholds of which should 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 speakers

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

Efficient worker (effectively reproducible) frequency range - the range within which the sound pressure level developed by the AU is not lower than the specified one, in relation to the level averaged over a certain frequency band. In IEC 581-7 recommendations, the minimum requirements for this parameter are 50 - 12500 Hz with a roll-off of 8 dB in relation to the level averaged over the frequency band 100 - 8000 Hz.

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

At low frequencies, the volume of the speaker cabinet plays a decisive role. The larger it is, the more effectively low frequencies are reproduced, so, in particular, subwoofers are always quite bulky. With the reproduction of high frequencies, problems usually do not arise, since modern tweeters allow even ultrasound to be reproduced. Often the range of reproducible frequencies of the speakers exceeds the upper limit of human hearing. It is believed that in this case the timbre of a complex phonogram, for example, symphonic music, is more accurately transmitted. Typical values: 100 - 18000 Hz for shelf acoustics and 60 - 20000 Hz for outdoor.

Serious loudspeaker manufacturers usually give a graph of the sound pressure developed by the loudspeaker as a function of frequency (an amplitude-frequency characteristic (AFC) graph), by which one can determine the effective operating frequency range of the loudspeaker and the unevenness of the frequency response.

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

Directivity allows you to evaluate the spatial distribution of sound vibrations emitted by the acoustic system, and optimally position the acoustic systems in different rooms. This parameter allows you to judge the directional diagram of the speaker, which is the dependence of the sound pressure level on the angle of rotation of the speaker relative to its working axis in polar coordinates, measured at one or more fixed frequencies. Sometimes the decrease in the amplitude-frequency response when the speaker is rotated by some fixed angle is displayed on the main graph, in the form of additional frequency response branches.

Characteristic sensitivity - this is the ratio of the average sound pressure developed by the speakers in a given frequency range (usually 100 - 8000 Hz) on the working axis, reduced to a distance of 1 m and an input electrical power of 1 W. Most Hi-Fi speakers have an intrinsic sensitivity level of 86-90 dB (dB/m/W is often used in technical literature instead of dB). There are high-quality broadband speakers with a sensitivity of 93 - 95 dB / m / W or more.

Intrinsic sensitivity determines how much dynamic range a speaker can provide. A wide dynamic range allows you to reproduce complex musical works, especially jazz, symphonic, chamber music, with great reliability.

THD characterizes the appearance in the process of conversion of spectral components that were absent in the original signal, distorting its structure, that is, ultimately, the fidelity of reproduction. This is a very important parameter, since the contribution of speakers to the total coefficient of non-linear distortion of the entire audio path, as a rule, is the maximum. For example, the coefficient of non-linear 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 non-linear 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 particular room.

Several types of capacities 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 (limiting) noise or nameplate power at which the AU can operate for a long time without mechanical and thermal damage when tested with a special noise signal close in spectrum to the real one music programs(pink noise). According to the measurement technique, it coincides with the nameplate power, determined in domestic standards.

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

Maximum (limiting) short-term the power that the AU can withstand when tested with a noise signal with the same distribution as for 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 applied to the speakers. Acoustics is considered to have passed the test if there are no noticeable distortions. It is clear that “under the distortions noticeable by ear” you can understand anything. As a result, stickers like “P.M.P.O. … (or Musical Power…)…100!, …200! and even… …1000 Wt!”. It is clear that there is no need to talk about at least some quality sound created by such speakers.

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

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, 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 watts.

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 an impedance corresponding to that specified in the amplifier's passport. Such a solution will provide an ideal match between the characteristics of the acoustics and the amplifier, that is, the best sound quality.

Measurement of the characteristics of the speakers in conditions that differ from the conditions of specially equipped acoustic laboratories of manufacturers is an extremely complex, costly and, most importantly, giving 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 dampened 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, what is called "in change". And they make a big 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 much this influence is.

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

Conductors in any electrical cable or wire are metals. Audio cables use mostly copper and silver. In 1984, Hitachi released the SAX-102 interconnect cable, which immediately attracted the attention of professionals. It was made from the so-called oxygen-free copper OFC (Oxygen Free Copper). Now almost all specialized "cable" firms use such copper. Why is oxygen-free copper good? The conductor metal can be viewed as a series connection of metal granules. Within each granule, the crystal structure remains ideal, but the interfaces between the granules disturb the crystal lattice. As a rule, the causes of the appearance of interfaces are films of oxides, oxygen compounds with metals. Due to the fact that OFC is cast and stretched in a certain way, the length of the ideal pellets is increased. Typical high purity copper contains about 5,000 grains per meter of cable. Improvement in OFC technology has led to the emergence of higher quality OFHC (Oxygen Free High Conductivity) oxygen-free high-conductivity copper, the number of grains per meter of which was 1000. There are other varieties of oxygen-free copper wire technology.

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

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

Since audio cables connect the amplifier to the speakers and work with rather high currents, designers first of all pay attention to the active resistance of the conductor: the smaller it is, the better. Firstly, because the ohmic resistance of the cable is connected in series with the ULF output resistance and the AC input resistance, and a relatively high-resistance connecting wire can drastically degrade the quality of the ULF and AC, and, secondly, according to the Joule-Lenz law, the thermal heating of the wire is proportional to the second the degree of current flowing through it. Reducing the ohmic resistance of the conductive lines is achieved by increasing their cross section. Therefore, the audio cables are quite thick. Acoustic wires are relatively low-frequency (the operating range is 4-5 orders of magnitude: from units of hertz to hundreds of kilohertz). And yet, most developers, having achieved the minimum resistivity value (0.001–0.05 Ohm/m), try to reduce the wire inductance (a typical value of specific inductance is 0.2–0.5 μH/m). Almost all wires, with the exception of flat tape ones, are made in the form of bundles assembled from separate thin wires. The simplest are a pair of insulated conductors ("noodles"); this design is most common due to its lowest cost. 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 over the cross section of the conductor does not change in order to remain close to the surface of the cable, the current passes through the interface from one strand to another. It happens that the contact between individual strands is not always good (there is a layer of oxides on the surface of each strand that conducts current poorly), and numerous transitions through resistance barriers can theoretically affect the transmitted signal. If you cut the old network wire in rubber insulation, a dark film of oxides attracts attention. Such a wire is not soldered without stripping, the ohmmeter shows a rather large resistance ...

To reduce the influence of the skin effect, each thin core is sometimes provided with its own insulation, however, such cables are not technologically advanced, 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 that differ not only in internal structure, but also in external features: round in cross section, flat, like thin ribbons, single, double, quadruple, etc. Despite their high cost, flat wires are very popular in home theater installations because they are easily hidden under wallpaper, carpets, and the like. Twin wires in pairs are in demand, which are convenient for connecting acoustics according to Bi-Wiring and Bi-Amping schemes.

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

How to choose speakers for ordinary PC users and for true music connoisseurs, who by ear determine the purity and level of sound, love to listen to melodies. Acquaintance with the main criteria of columns, their characteristics and purpose. This article will help you make the right choice.

Criterias of choice

It all depends on the purpose for which you buy speakers. To simply play sound in a computer, you will need to buy classic 2.0 speakers. The sound quality is good, the price is reasonable. But not every layman can be satisfied with such a simple audio system. In order to understand exactly what columns will be used for, study their main criteria and familiarize yourself with the main functions.

What are the columns:

1. For traveling with a laptop the best choice would be portable speakers (see how to choose portable speakers) that connect via Bluetooth and have powerful battery. They take up little space and do not require a network connection. Although they lose in sound quality.
2. For home or office computer 2.1 speakers are suitable, they cope with the transfer of any audio and video files, do not beat on the ear when working on raised tones.
3. For professional DJs the best choice there will be 2.1 format acoustic equipment.
4. For fans of movies and video games with special effects fit 5.1 speakers
5. For connoisseurs of surround sound, a system for home theaters is suitable for a computer in all respects.

What do the mysterious numbers "2.0", "5.1" and "2.1" mean? These are the speaker type designations: the first number is the number of speakers and the second number is the number of subwoofers. There are also projectors - soundbars. What are their differences?

1. The most popular option is 2.0, speakers recreate low, normal and high frequencies. Stereo pair of 2 speakers.
2. Option 2.1. Inexpensive option for listening to music and games. Experienced music lovers believe that such speakers drive rap and heavy metal quite well. Two speakers take on the mid and high frequencies, and the third - the subwoofer - low. It is she who guarantees a deeper bass than other, not so universal, systems.
3. Option 5.1. It is called extended format 2.1, here more columns: 2 rear and 1 center are added. But using such a system will not work on every computer, you need a special connector or the presence of a receiver. If you are going to watch chic blockbusters on your computer and play cool games with special effects, this is the perfect option for you.
4. Soundbars. A long column where the speakers are located. The model is very expensive, for professional musicians. They guarantee the quality and sound level even in a large room, without placing the speakers themselves around the perimeter.

Now - about the material of the speaker cabinets .

1. Wooden- the price is higher, but they have more surround sound. And their most important plus is that they do not rattle.
2. Plastic- an order of magnitude cheaper, more choice of models, but the acoustics are worse, passive ones will wheeze a lot.
3. From MDF. Compromise between price and quality. They are inexpensive and sound good, without rattling and look pretty stylish.
4. With the use of metal. Such cases are made for high-tech office equipment. Good sound, the view is quite presentable, but the price is high.

There is also a classification into active and passive speakers.

1. Active characterized by a rich sound and a smooth transition between tonalities. Built-in amplifier, power from PC.
2. Passive they are cheaper, because the sound quality is modest, you need an amplifier.

Now let's decipher another such term. One-way acoustics is 1 speaker that reproduces frequencies, two-way acoustics - 2 speakers, for low-mid frequencies and high frequencies. In a three-way speaker - 3 speakers for each frequency separately.

Characteristics of computer speakers

What is important when buying computer speakers? Experts advise to pay attention to such characteristics:

1. Frequency range. A set of sound effects depends on it. For work and watching movies, 20 thousand Hertz is enough, but music lovers should “climb” higher.
2. Sensitivity. The higher it is, the further it goes sound signal while maintaining high quality. Best Choice will be at 85-100 decibels.
3. Power. The most important indicator. For simple sound reproduction, 20 watts will be enough. Music lovers and fans of large music companies should choose an option with indicators of at least 50 watts.
4. Dimensions. Small size and great sound, powerful frequencies - this is extremely rare. Therefore, for good sounding, you have to allocate space.
5. With microphone. These are purchased for Internet conferences, so as not to spend money on a set of audio equipment.

Power of different types of speakers

1. Office. Power - from 2 to 6 watts per speaker, this is quite enough for work.
2. Homemade. Power - about 30 watts for each, if a loud sound is not needed, 10-15 watts will suffice. If you want to listen to music loudly, then the indicators should be about 50 watts. The requirements for gaming columns are similar. For powerful systems, at 5.1 and 7.1, they consider the total power, where the numbers are needed from 150 to 500 watts. Fans of quiet music will have enough for 75 watts, for large companies you need to take at least 150. It all depends on how much you are willing to spend (the higher the figures, the higher the price).
3. Portable. These have an average of 4 watts per speaker. If the power comes from Bluetooth, it is better to buy at 2-3 watts, if from a socket - then at 4-6.

Top 10 Best Computer Speakers

In the modern market, there is a constant struggle between manufacturers of office equipment, so far the first positions in the TOP-10 are retained by such models:

1. . Speaker power 4 W, made of MDF material. One-way sound. Frequency range from 90 to 20000 Hz.

• the headset is easily and quickly connected;
• powered by USB;

Cons: Not much power.

2. . Small-sized case, full-range speakers, 6 W power, USB connector provides power to the built-in amplifier. Made of plastic, frequency range - from 80 Hz. The classic version for the computer.

• consumes little energy;
• powered by USB;
• passive emitter.

Minus: no power supply, you have to buy extra or take up a computer port;

3. . The case is made of MDF, very similar to wood, the power of both speakers is 6 W (3 for each), single-band sound, from 90 Hz.

• USB powered;
• brightly illuminated volume control;
• power supply included.

Minus: the kit does not include side speakers.

4. . The speakers have a power of 1.2 W, a frequency of 20 Hz, the model is made of plastic.

• compactness;
• Easily connects to laptop via USB.
• cables of the correct length.

• play well, but without bass boost;
• stamped body.

5. . Titanium tweeter, aluminum frequency converters, power is not distorted - up to 120 watts (60 for each). The weight of the column is 8 kilograms, the connectors are located in the back wall, the control panel compensates for the inconvenience. Frequency range from 48 to 20000 Hz.

• Bluetooth and digital interfaces;
• material - wood;
• clear and bassy sound at high volume.

6. . Mini music center, sound is played from USB flash drives and memory cards. bluetooth. Can be amplified with a subwoofer, but the value for money is quite decent. Power 50 W, power up to 25 thousand Hz. Material - MDF.

• clear and powerful sound;
• wireless connection;
• the presence of a remote control.

Minus: non-standard glossy front panel.

7. . Dual-band audio, Bluetooth, support for aptX audio transmission, in conjunction with NFC. Good for laptops since you don't have to unplug the line cable. You can also listen to music from your smartphone. Power 28 W, made of plastic.

• separate tone control on each of the bands;
• headphone jack;
• turns off automatically;
• you can work with and without a wired connection;
• powerful bass.

Minus: high price (from 8000 rubles).

8. . PC-only speakers, as the dimensions are quite impressive. Original retro design. Two-way acoustics, regulators can change the tone of frequencies. Power for both speakers - 60 watts. The frequency range is from 50 to 20 thousand. Hz.

• no wheezing even at high volume;
• clear and powerful sound;
• two microphone jacks;
• reverb;
• high power.

9. . The original feature is the remote control, which is connected to the amplifier, with the headphones connected. Switching on only by the line input, only the bass is regulated. System power - 40 W (20 for each speaker), frequency range - from 55 to 20 thousand. Hz. Material - MDF.

• compactness;
• convenient setting.

No cons found.

10. . High-quality sound is guaranteed by 2 satellites, plastic 85 mm mid-range drivers, bass-reflex subwoofer. The total power is 110 watts. MDF cabinet. Frequencies from 30 to 20 thousand Hz.

• IR remote;
• remote display with control buttons;
• case color can be chosen: red or brown;
• powerful reinforcement.

Minus: increased price due to the remote screen.

The Most Advanced PC Speaker Models

Option 5.1 is called the leading computer acoustics. Introduced on DVD and in computer toys. The most improved models:

1.Logitech Z Four 67W wall mounted speakers, 1 center channel speaker of the same power, and a 165W subwoofer. You can control the acoustics, even select the inputs for the sound source. From 22 thousand rubles.

• stereo 3D, 4.1 and 2.1 effects;
• up to 6 sound sources;
• recorded from the network;
• Remote Control;
• original design.

Cons: No mounting screws.

2.. The most advanced version. Acoustics 5.1. The body is made of MDF boards, without harmful impurities that improve the sound quality. Optimal heat mode, minimum interference. The power for both speakers is 540 W, the frequency is from 42 to 20 thousand Hz. Inert radiator technique that guarantees rich bass. From 24 thousand rubles.

• there is a remote control;
• smooth bass, clear sound;
• original design;
• subwoofer 10 inches.

Cons: large size.

3. Made of MDF, classic design, 6 channels, powerful speakers and subwoofer. Power - 84 watts. Pure sound thanks to super-method Frequency from 30 to 20 thousand Hz. Price from 8 thousand rubles.

• controlled by a remote control;
• you can connect multiple audio sources;
• magnetic shielding;

Minus: not long wires.

4.. It is positioned as not very expensive acoustics with excellent sound. Power - 75 watts, frequency - from 45 to 20 thousand Hz. There is a magnetic shield. Multiple inputs, can be connected different devices.

• inputs are switched by a special button;
• convenient management;
• high build quality.

Minus: no remote control.

Those who better absorb visual material should familiarize themselves with the visual recommendations of experts. Professionals offer the most best options acoustics.

What you should pay attention to

Buyers usually focus on design, convenient connection and use. Here, too, there are tricks.

• Often you have to overpay for the design, because the speakers are simpler, often they sound even better.
• Location of control knobs. It is more convenient if placed in front or on the side. Even with a remote control, this aspect still needs to be taken into account.
• It is desirable that the functions are available not only from the console, for example, the transition of inputs or tone adjustment.
• It is much more optimal when the power amplifier is in the external unit. Easy to move.
• The sound quality does not affect whether the amplifier is mounted in the speaker or not.
• It is believed that the stronger the power, the better model. There are standards. For a room up to 20 squares, about 20 watts is enough, 10 watts per speaker. But for a large hall, up to 100 is suitable.

Two-way speakers have clearer high frequencies. And the advantage of three-way is clearer mids and more bass.

• When buying portable speakers, it is worth checking whether a battery is attached to them. Because without it, the speakers will not last long.

When choosing speakers for your computer, there are many aspects to consider. Before buying, decide on the main requirements for the product, and focus on them. If you can afford only inexpensive ones, it is better to buy those that do not have a popular brand, but offer high-quality sound.

In contact with

What is important in such a peripheral device as laptop speakers? The market for offers is enormous, how to be able to choose good speakers, while not overpaying and not disappointed by the terrible sound? Read our brief educational program, which will guide you on how to choose computer speakers.

Agree that the computer is now a kind of combine that implements the functionality of several devices and performs complex tasks for our work, entertainment, education, control and security, communication.

In any case, having one computer with a network connection, you can not buy a radio, or a TV, or game console, not even a book (!), not a phone, but still be with music, and with videos, and with games, and with books online, as well as communication - thanks to instant messengers.

So for many PC or laptop is multifunction device, which replaces several gadgets. And for modern life, this is probably a convenient format: saving money, once (after all, the total amount for a separate TV, music center, speakers, set-top boxes, book reader, phone will be colossal), two - very ergonomically in a small apartment, or if temporary housing - moved a laptop, and voila, there is no need to transport more equipment.

But even for a laptop that has integrated speakers, not to mention a stationary desktop PC, it's worth buying a speaker system. In other words, computer speakers.

Because the sound from the speakers of a laptop - even the most expensive one - is no-what. The sound of your favorite track, even in mp3 format, also through those weak channels that are installed in laptops due to the compactness of the form, it will be, to put it mildly, distorted. Bass will be lost, mid frequencies will not be reached, in a word, you cannot listen to music through the laptop's speakers. Some sounds from the system or from messengers are one thing. But to listen to music tracks, playing a laptop will, to put it mildly, not be enough. And for even watching videos, speakers are needed - so as not to constantly listen to the sound range of the movie.

Acoustics for a computer can be very cool - from well-known sound brands, capable of producing very accurate and rich sound - everything will already depend on the quality of the sound content itself that the computer will play. But such a product is practically not in demand in the consumer market, and is not needed for media entertainment through a computer. HIFI- columns. Although, of course, if you already have a 7.1 stereo system for your home theater, you can probably connect it to a laptop as well.

Read also:

However, the most common queries are simply to find laptop speakers. In principle, this determines the class of acoustics itself, which has its own parameters that indicate the quality of the sound that they will produce.

Types of speakers for a computer

The simplest - 2.0 - that is, the usual 2 pieces of columns. The next level - with a la subwoofer - 2.1. Systems 5.1 or 7.1 - this indicates the number of speakers, with different frequency ranges.And for such systems, it is important that the laptop or PC has a video card of the appropriate power.

The most common PC or laptop speakers are 2.0 or 2.1 systems. They can be wired or wireless - but let's not get ahead of ourselves, let's start in order.

Before choosing, you must understand the specific characteristics of acoustics - they are fundamental. They will "explain" to you not only the price tag, but also the capabilities of the device - what kind of sound you can expect from them. Even if you buy with the help of a consultant, and not on your own online, knowing about the elementary specifications of the speakers will help you buy exactly what you need, and the power and frequency numbers will not be “white noise” for you.

Notebook speaker specifications

1. Dimensions and materials of the acoustic system

2.Connection method (wired/wireless)

3.Power

4.Frequency range

5. Sensitivity

6. Number of lanes

7. additional features(volume adjustment method, frequency adjustment

8.Brand

And now in more detail about each of the characteristics.

Speaker sizes matter, because, whatever one may say, the more, the more sound they can give out (the size of the speaker, for example, clearly determines the high volume) Miniature speakers are quite suitable for office purposes when there is a space limitation.

The body material also plays a role in the sound, but not as important as, say, for class acoustics. HIFI or HI-END. However, to say that there is no difference what the columns are made of is impossible. Of course, a priori speakers made of wooden materials will sound better than plastic ones, since plastic absorbs sound. And it is desirable that the thickness of the body was not thin and not too thick.

If you carry a laptop all the time, then the speakers, of course, cannot be too large. Miniature, preferably wireless - what you need. Although, of course, you can’t count on any stereo sound with them. As well as the indicators of power and volume.

The connection method can be wired via USB connector, or maybe through a socket and jack 3.5 connector mm. Wireless s e models connect via Bluetooth connection.

Power

The numbers indicating power should not always be taken as an absolute indicator. Therefore, it is desirable to distinguish and clarify exactly what power the manufacturer-seller indicates: nominal, maximum or peak.

The rated one is a clean, noise-free, high-quality sound, and the peak one is how much the system can withstand at its maximum, the maximum power is the “working” state of sound reproduction with possible defects.

A combination of a number of indicators will indicate the real sound of the speakers, although, of course, power is an important parameter.

The power of speakers for a PC or laptop can be 2/3 W - if we are talking about office speakers, then this is quite enough. However, it is more optimal if this figure were more than 3 watts. Recommended for a medium-sized room up to 20 sq.m - from 10W, 5W for each speaker. Ideally - about 20 watts.

Frequency range

The wider it is, the steeper the sound will be. The human ear is able to distinguish between waves at a frequency of 16-20 to 20,000 Hz. So if it says laptop speakers have a range of 19Hz to 15000Hz, those are cool speakers. But on average, the range of PC speakers is between 40-10000Hz.

Sensitivity

This characteristic determines just the volume. With equal power indicators of two columns, the one whose sensitivity is higher will be more effective. The sensitivity range is traditionally within 84 - 120 dB. The optimal sensitivity figure is not lower than 87 dB.

Number of lanes

For many who are not familiar with the nuances of stereo sound, this characteristic is not clear.

But it's very simple: stripes = number of speakers. If there is one speaker in the speakers, it means a single-band sound, the speaker “produces” all sounds from one speaker. And if 2-3 speakers are mounted in the speakers, this means that each speaker is assigned the task of reproducing sounds of different frequencies. So, three-way speakers - one speaker for low frequency sounds, the second for medium, and the third for high frequency sounds. And multi-band, of course, give out a richer, richer, surround sound than single-band.

Additional details

Often there are models where sound control is at the back - alas, this is not the best option. Choose speakers with volume controls on the front or on the side. The wireless remote control is not bad, but as a backup option, and not the only one.

Please note that a number of functions can be transferred to the remote control - switching inputs, timbre. It is good if each frequency range is regulated separately.

Brand

Of course, when choosing equipment (and speakers are no exception), you should use the rule - brand profile. That is, those brands that specialize in a particular type of product and have been creating it for a long time are preferable. Therefore, brands such as Logitech, Edifier, Microlab are a very worthy choice.

More budget options, but also with decent characteristics in a number of models - from manufacturers Sven, F&D, Gemix, Genius.

On room acoustics, we found that any room is a kind of resonator that dramatically affects the character of the sound of the system. Now it's time to talk directly about the sources of this very sound, that is, about the acoustic 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 carefully read a couple of books, each of which contains more formulas than in the entire school physics course. I will not get into such a jungle, so this material is not worth it as an exhaustive analysis or guide to building audiophile speakers. However, I really hope that it will help novice music lovers (and some chronic ones too) to properly navigate the variety of acoustic solutions, each of which, of course, its developers call the only correct one.

Some time after the invention in 1924 of an electrodynamic radiator with a conical diffuser (okay, just a speaker), its wooden frame performed primarily decorative and protective functions. It is understandable - after many years of listening to records through mica membranes and bells of gramophones, the sound of the new device and without any acoustic refinement seemed just the apotheosis of euphony.

Gramophone membranes were most often made of aluminum or mica.

However, recording technologies were rapidly improving and it became clear that it was extremely problematic to reproduce the audible range more or less plausibly with a speaker simply mounted on some kind of stand. The fact is that the dynamic head left to itself is in a state of acoustic short circuit. That is, the waves from the front and rear surfaces of the diffuser, radiated, of course, in antiphase, freely overlap each other, which most sadly affects the efficiency of work, and especially the bass transmission.

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

Soul wide open

The easiest way to separate the speaker's front and rear radiation is to mount it on a shield as large as possible. From this simple idea, the first acoustic systems were actually 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 too impressive. In addition to the imperfection of the body, the problem was also in a very small diffuser suspension course, according to modern concepts. In order to somehow get out of the situation, the speakers were used as large as possible, capable of developing an acceptable sound pressure with a small amplitude of oscillation.

PureAudioProject Trio 15TB with 15" woofers on 3-layer bamboo panels

Despite the apparent primitiveness of such structures, they also had some advantages, and so specific and interesting that the adherents of open speakers have not died out so far.

To begin with, the absence of any obstacles in the path of sound waves is the best way to increase sensitivity. This moment is especially valuable for audiophile tube amplifiers, especially single-ended or devoid of feedback. Paper cones of large diameter, even at a power of about four or five watts, can create a rather impressive, and at the same time surprisingly open and free sound.

With a height of 1.2 m in the world of open acoustics, Jamo R907 are considered almost compact

As for the back radiation, in order not to introduce distortions into the direct sound, it must arrive at the listener with a noticeable delay (over 12-15 ms) - in this case, its influence is felt as a slight reverberation, which only adds air to the sound and expands the musical space . The subtlety is that in order 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 bass drivers have a corresponding effect 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 of open systems is 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 have 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 an enviable timbre accuracy.

open decoration

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

Minuses: It is better to forget about fat compression basses right away. Whole audio 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 growth of power and the improvement of the parameters of amplifiers, 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 relevant.

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 the current patent trolls.

Patent application of Edgar Vilchur for AU in a closed format

By that time, a phase inverter had already been invented and, of course, the speaker was also repeatedly tried on to a box with a bottom, but nothing good came of it. Due to the elasticity of the closed volume of air, it was necessary either to lose a significant part of the energy of the diffuser, or to make the housing 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 shifting the control of the movement of the diffuser to the volume of air - a spring much more linear and stable than a corrugation or a rubber ring.

In a closed box, the movements of the diffuser are controlled by air - unlike paper or rubber, it does not age or wear out

So it was possible not only to completely get rid of the acoustic short circuit and increase the output at low frequencies, but also significantly smooth out the frequency response throughout its entire length. However, there was also a minor moment. It turned out that damping by 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 such a nuisance, it was necessary to increase the mass of the diffuser, which logically led to a decrease in sensitivity. Plus, the absorption inside the "black box" of almost half of the acoustic energy could not help but contribute to the reduction of sound pressure. In a word, a new type of speaker required amplifiers of quite serious power. Fortunately, at that time they already existed.

Subwoofer SVS SB13-Ultra with closed acoustic design

Today, the closed design is used mostly in subwoofers, especially those that claim serious musical performance. The fact is that for home theaters, the 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 subwoofer with decent satellites, you can achieve a much more correct sound - albeit not filled with ultra-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 resolution in the low frequency range. Relative compact design.

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

Case - pipe

Another way to curb the anti-phase rear radiation was the phase inverter, in Russian literally “phase unfolder”. Most often, it is a hollow tube mounted on the front or rear surface of the case. The principle of operation is clear from the name and is straightforward: once you get rid of radiation reverse side diffuser is difficult and irrational, so you need to synchronize it in phase with the frontal waves and use it for the benefit of the listeners.

The amplitude and phase of air movement in the phase inverter change depending on the frequency of the diffuser oscillations

In fact, an air pipe is an independent oscillatory system that receives an impulse from the movement of air inside the housing. Possessing a completely defined resonance frequency, the phase inverter works the more efficiently, the closer the cone oscillations are to its tuning frequency. Sound waves of higher frequencies simply do not have time to move the air in the pipe, and lower ones, although they have time, but the lower they are, the more the phase inverter phase 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 explains the very steep drop in speaker sound pressure below the bass reflex tuning frequency - 24 dB / oct.

In the fight against turbulent overtones, phase inverter designers are constantly experimenting

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 tricks in order to minimize the resonant frequency of the speaker itself, which is rather troublesome and expensive. It is much easier to set up a phase inverter tunnel - just select its internal volume. This is true in theory. In practice, as always, unforeseen difficulties begin, for example, at high volume levels, the air leaving the hole can make noise almost like wind in a stove chimney. In addition, the inertia of the system often causes a drop in attack speed and poor articulation in the bass. In a word, the space for experiments and optimization before the designers of phase inverter systems is simply incredible.

Phase inverter

Pros: Energetic feedback on low frequencies, the ability to reproduce the deepest basses, relative simplicity and low cost of manufacture (with a fair amount of calculation complexity).

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

Let's go without a coil

Attempts to get rid of the genetic problems of the phase inverter, and at the same time save on the volume of the case without compromising the depth of the bass, prompted the developers to replace 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 a voice coil.

A passive radiator can double the effective surface of the diffuser, or even triple it if they are installed in pairs in one column.

The design was called "passive radiator" (Passive radiator), which is often not too well translated from English as "passive radiator". Unlike a subwoofer tube, a passive cone takes up much less space in the cabinet, is not as critical to location, and besides, like the air inside a closed box, it dampens the main driver, smoothing its frequency response.

Subwoofer passive radiator REL S/5. The main driver is directed to the floor

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

Passive radiator

Pros: Compact body with impressive bass depth. The absence of phase inverter overtones.

Minuses: An increase in the mass of the radiating elements leads to an increase in transient distortion and a slowdown in the impulse response.

exit from the labyrinth

Acoustics, armed with phase inverters and passive radiators, reproduce deep basses thanks to resonators working with the mediation of air inside the speakers. However, who said that the volume of the column cannot play the role of a low-frequency radiator by itself? Of course it can, and the corresponding design is called an acoustic labyrinth. In fact, it is a waveguide, with a length of half or a quarter of the wavelength, at which it is planned to achieve system resonance. In other words, the design is tuned to the lower boundary of the speaker frequency range. 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.

The acoustic labyrinth is a favorite design of DIY acousticians. But if desired, the case of the most cunning form can be ordered ready-made

In order to accommodate even a twice as compact design in a column of reasonable dimensions, baffles are installed in the case, forming the most compact curved waveguide, with a cross section approximately equal to the diffuser area.

The labyrinth differs from the phase inverter in the first place by its less “resonant” (that is, not accentuated at a certain frequency) sound. The relatively low speed and laminar nature 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 practically no obstacles.

Schematic for case calculation at dbdynamixaudio.com

There is an opinion that acoustic labyrinths create less problems with standing waves in the room. However, with the slightest miscalculation in design or manufacture, standing waves can occur in the waveguide itself, which, unlike a phase inverter, has a much more complex resonance structure.

In general, it must be said that a competent calculation and fine tuning acoustic labyrinth - the processes are very difficult and time-consuming. Exactly because of this reason given type cases are rare, and only in speakers of a very serious price level.

acoustic maze

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

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

Hey, on the ferry!

Horn - the most ancient and, perhaps, the most provocative type of acoustic design. It looks cool, if not outrageous, it sounds bright, but at times ... In old films, the characters sometimes shout something to each other, and the characteristic coloring of such a sound has long become a meme in both the music and cinema worlds.

Avantgarde Acoustics Trio with 2.25 m Basshorn XD low frequency horn array

Of course, the current acoustics have gone very far from a tin funnel with a handle, but the principle of operation is still the same - the horn increases the resistance of the air to better match 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 the structures described earlier, the horn is most often used in high-frequency speaker units. The reason is simple - its cross section increases exponentially, and the lower the reproducible frequency, the larger the size of the output hole should be - already at 60 Hz a bell with a diameter of 1.8 m is required. It is clear that such monstrous structures are more suitable for stadium concerts, where they really can be found periodically.

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

Realhorns systems - special acoustics for special occasions

Skeptics do not get tired of reminding about the characteristic horn coloring, especially noticeable on vocals, and giving it a characteristic nasality. It is really not easy to overcome this trouble, although judging by the way the best examples of High-End horns play, it is quite real.

mouthpiece

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

Minuses: Characteristic difficult-to-remove coloring of sound, childish sizes of medium- and even more so low-frequency structures.

Circles on the water

It is by this analogy that the easiest way 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 not 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 expanding the air gap. As a result, circular air waves are created that radiate evenly in all directions. Moreover, the characteristics of these waves during their propagation are distorted minimally, and their energy decays slowly - in proportion to the distance, and not to its square, as in the case of conventional speakers.

Duevel Sirius combines elements of horn and contra-aperture designs

In addition to the range and circular orientation, counter-aperture systems are interesting for their surprisingly wide vertical dispersion (about 30 degrees versus the 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 the oscillation of the cone. True, the real 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 extensive and uniform zone of surround perception, that is, in fact, the issue of precise positioning of the speakers relative to the listener becomes irrelevant.

Italian-Russian counter-aperture acoustics Bolzano Villetri

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 ...

Nautilus from Bowers & Wilkins is one of the most unusual, expensive and authoritative speakers in terms of sound. Type of design - loading 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.

Adapted from Stereo & Video Magazine, June 2016