Test of bookshelf Hi-Fi acoustics in the mid-price category. Detailed explanation of some characteristics of acoustics Phase of the input impedance of the acoustic system

Even during periods of economic crisis, the flow of true music connoisseurs does not dry out, for whom it is important not just to listen, but also to hear their favorite compositions as they sounded “live”, from the stage. Of course, it is not difficult to satisfy such a need today - if only there was money! Well, if finances are tight, but you still want to listen to Hi-Fi music, what should you do? For this purpose, we decided to test bookshelf speaker systems that successfully combine Hi-Fi sound quality and an affordable price corresponding to the average price category. Of course, these are not “sophisticated” acoustics, but if we compare floor-standing acoustics with bookshelf speakers according to the “price/quality” criterion, then the latter even come out on top. The only thing I want to warn you about in advance. Bookshelf monitors do not always have ideal bass depth, but this deficiency is more than compensated by the excellent sound of the speakers at low volumes. But in the end, who do we listen to music for - for our neighbors or for ourselves? Well, choosing a suitable speaker from the twelve tested models will be easier. So think, compare, enjoy!

Criteria for evaluation

Since we are talking about an established category of classic monitors, testing will be standard. The amplitude-frequency response and nonlinear distortion coefficient will objectively show to what extent the monitor design corresponds to the acoustic parameters. At the same time, the design features of each model will be studied, and a total design assessment will be obtained as a whole. During testing, the sound character of each will be examined simultaneously. speaker system. As a rule, bookshelf formats rarely combine good bass depth and high playback quality, so this indicator will be mentioned in testing, but only as a reference. But as for the playback characteristics uppercase, which is extremely important for the presentation of musical material, then the testing here will be quite thorough. The nature of the sound at low volumes will also be indicated separately, which indicates the smooth (almost linear) dynamics of the speaker systems. The timbral authenticity of the music scene will not be left without attention. Taken together, all this will make up the sound rating.

Acoustic Energy 301

• Sound: 4
• Construction: 4
• Cost: 4

Advantages:

• great detail
• timbre accuracy

Flaws:

• there is a lack of air

When developing the 300 series, British designers managed to embody exquisite laconicism. Covered with white or black varnish, the speakers look neutral and strict. The joints of the panels, like the rest of the body elements, are made delicately, without any frills such as fasteners or protruding screws - in all respects, this bookshelf model is made in the classic style of “professional” Hi-Fi acoustics. The front panel of the Acoustic Energy 301, which is finished with a black rubber-like coating, houses a proprietary 28mm fabric dome tweeter and a proprietary 110mm woofer made of bent anodized aluminum. By the way, the legendary AE1 monitors, recognized by experts as a standard, once had exactly this type of head.

The output hole of the slotted bass reflex is also located at the bottom of the front panel. This original engineering solution has several advantages. Firstly, these speakers can be placed almost anywhere, even almost moved to the wall without fear of distorting the sound - thereby simplifying the installation of the speakers. Secondly, the bass reflex on the front panel does not distort the frequency response in the mid-bass region, and at the same time allows for better matching of the lowest frequencies with the room parameters. And this detail: the solid internal volume of the speaker (with a height of 300 mm and a width of 185 mm, the depth of the speaker is 250 mm) made of massive MDF sheets also ensures excellent bass sound. With such capabilities, this shelf model of the monitor is practically not inferior to its more expensive floor-standing “brothers,” especially when working in small rooms.

Sound

And if we are talking about sound quality, it should be noted that there is no even subtle coloration in almost the entire range. Despite the fact that even the smallest nuances of music can be clearly heard on the Acoustic Energy 301 speakers, the timbres are almost natural. This indicates that the monitor's frequency scale is balanced in both level and dynamics, and these speakers produce consistent sound. Despite the fact that the bass register is very clearly distinguishable and the middle range is perfectly audible, at the highest frequencies there is no, no, and the slightest rise slips in, which is especially noticeable on complex musical material, when its perception is somewhat reduced. This picture is typical for both high and low volumes.

Measurements

With equal amplitude frequency response at the highest frequencies it starts to go up a little. The decline in the low-frequency region is uniform. The bass is of high quality, of medium depth. The THD is quite low and is virtually independent of the volume level. Impedance is unstable.

Bowers & Wilkins 685

• Sound: 3
• Construction: 3
• Cost: 5

Advantages:

• good sound
• design

Flaws:

• slight change in timbres
• slight distortion
• presence of noise

This bookshelf model of the speaker system is a bright representative of the junior line of the British company Bowers & Wilkins. Old design speakers incorporates the technologies of this manufacturer’s flagships. Of course, we are talking only about inexpensive ones, but at the same time optimal solutions. First of all, these are Nautilus conical tubes for the tweeter, Kevlar diffusers, as well as a proprietary bass reflex port with the original golf ball surface. The two-layer aluminum tweeter dome is insulated with a special material, with the help of which it was possible to obtain surround sound. In the dynamics of mid and low frequencies, the recoil at the upper limit is smoothed out by a static bullet. The crossover responsible for sound purity is extremely simple. The body of the speakers is covered with film, but the front panel pleases with a velvety material that is pleasant to the touch.

Sound

This model is characterized by an open and bright sound with a good level of detail. The bass is accurate and fast, but could be more concentrated, but the noise makes itself felt. However, sound localization is very clear. The music lover will not be pleased with the little one dynamic range. In the mid-frequency range, the timbres of instruments are greatly simplified, and the high-frequency region is not heard as well as we would like and does not give the impression of airiness and spaciousness.

Measurements

In the ranges of 2.5 kHz and 6-7 kHz, irregularities appear, which can be eliminated by turning the speaker 30°. At the same time, the frequency balance goes somewhat into the low-frequency range. Characterized by extremely low SOI. The impedance is very unstable.

Canton Chrono 503.2

• Sound: 4
• Construction: 5
• Cost: 5

Advantages:

• clean high frequencies
• meticulous transmission of timbres

Flaws:

• Low frequency range is weak at low volumes

The German model Chrono 503.2 is characterized by excellent sound reproduction and traditionally high quality control. Although the manufacturer stated a glossy finish, the speaker body is covered with film, and only the front panel is glossy. On relatively compact speaker An impressive speaker (diameter 180 mm) with a traditional aluminum diffuser for this company is installed. To ensure the maximum possible linear and long piston stroke of the diffuser, the suspension is made in the shape of a wave. The tweeter is equipped with a lightweight 25 mm dome made of a durable alloy of aluminum and magnesium, which is also covered with a metal grill for reliability. The mobility of the speakers has also been thought out: so that they can be mounted on a stand or bracket, there are two threaded holes in the bottom of the speaker.

Sound

The speakers reproduce almost all musical genres quite clearly, with almost perfect frequency balance. Therefore, it is not surprising that the timbres of instruments sound practically without distortion, even subtle nuances. Although there is no increased emotionality expected with such parameters, the wide and smooth dynamic range of the speakers very reliably conveys the musical idea of ​​any genre - in this the speakers can be considered universal. The lower frequencies are collected and clearly distinguishable, but the bass is still not deep enough, and when the volume is lowered, it begins to “go away” barely noticeably. When you get acquainted with the speakers, you get the impression that the range of the upper register is too large, but after listening, you understand that high frequencies appear at those moments when it is necessary, and in sufficient quantities, without excesses. It is worth noting that the upper register of the speakers is crystal clear, and music fans will appreciate this.

Measurements

Speaking of good dynamic qualities this model, it should be noted that the ideal sound largely depends on the angle at which you listen: the monitor’s directivity is quite narrow. The nonlinear distortion coefficient is small, and a good margin is noticeable at low frequencies. Impedance is unstable.

Chario Syntar 516

• Sound: 3
• Construction: 4
• Cost: 4

Advantages:

• emotional and bright presentation
• precise localization

Flaws:

• simplification of timbres

The classic style of the Italian monitor is primarily distinguished by its natural wood veneer finish - both inside and outside, which significantly increases the durability of the speaker. The entire process of processing the body parts and their further assembly is carried out manually, which again increases the impeccable quality. Then the finished products are necessarily tested - without this, the speakers do not go on sale. The tweeter membrane (Silversoft Neodium model) is coated with silver aluminum powder - the same technology is used in monitors of the leading brand line. It is worth noting that the tweeter also reproduces a significant part of the mid-frequency range (from approximately 1 kHz). The double-curved shape of the mid/bass speaker diffuser was specially selected taking into account the recommendations of psychoacoustics. The asymmetrical hole in the bottom of the speakers is the bass reflex port. In order for it to work correctly, high rubber feet are attached to the bottom of the speaker.

Sound

This speaker system is characterized by both slowness and softness, complemented by an active and clear upper register. At the same time, the timbre picture is somewhat blurred, which is why sound nuances are veiled. Despite this, the speakers still reproduce musical compositions of different genres quite accurately and emotionally. The bass is so deep that it even stands out in the overall sound picture. Soundstage localization is good, but lacks transparency, which is especially noticeable when listening to complex compositions. As the volume is lowered, the bass begins to weaken, but the sound remains emotional and dynamic.

Measurements

The optimal amplitude-frequency response was recorded when the speaker was rotated by 30°. The model is characterized by relatively good unevenness with an even and smooth roll-off to low frequencies. The coefficient of nonlinear distortion is quite even - from the highest to the lowest frequencies. The impedance is quite stable.

Dynaudio DM 2/7

• Sound: 5
• Construction: 5
• Cost: 5

Advantages:

• authenticity of timbres
• clean highs

Flaws:

• excessive severity in sound delivery

In the group of bookshelf monitors, the Danish company Dynaudio is represented by the DM line. As you would expect, the company has designed the speakers in its signature style: a massive front gray panel is slightly thicker than the side walls to more effectively dampen unwanted resonances. The same applies to the body as a whole: it is delicately muffled and immaculately finished with classic veneer. The 28mm silk dome of the branded tweeter is treated with a special impregnation, but the midrange/bass driver cone is made of magnesium silicate polymer, which has proven itself well in the world of acoustics. The voice coils are wound on a Kapton frame with lightweight aluminum wire, and when paired with a powerful magnetic system, they produce excellent dynamics and sensitivity. The designers of these speakers paid great attention to maximizing impedance equalization to minimize speaker dependence on the amplifier.

Sound

The speakers reproduce music freely and naturally, and the beautiful sound of the tones transforms the sound stage into a natural one, producing an expressive and balanced sound. Indeed, you get the impression that you are at a “live” concert and can clearly hear where which instrument is located. Low frequencies are tight, energetic and distinct. The upper register is refined, clean and expressive. All the details are well worked out in the sound and there is no coloration. It is also worth noting that the speakers play equally confidently at both low and high volumes.

Measurements

The amplitude-frequency response is a flat line with a slightly noticeable shift into the HF range. The model is characterized by a broad focus. The nonlinear distortion coefficient is stable and low, as is the impedance. In total - excellent results.

Magnat Quantum 753

• Sound: 5
• Construction: 4
• Cost: 4

Advantages:

• precise tones
• clear sound stage

Flaws:

This bookshelf monitor from the German company Magnat Audio-Produkte from the Quantum 750 line is perhaps one of the most impressive of the speakers under review. To minimize cabinet resonance, the front panel of the speaker is made of a double-layer 40 mm plate, the thickness of the podium is 30 mm. The legendary German solidity is emphasized by the muted, austere matte surface of the case, and only the podium with the front panel playfully sparkles with careful polishing. The Fmax tweeter (by the way, a proprietary development of Magnat) has a dome made of a double fabric compound, which provides an extended working band. As for the midrange/woofer cone, it is made of aluminum coated with ceramic particles. This model also features a well-ventilated voice coil. The shape of the aluminum speaker basket was also thought out so that the air flow passes freely and reduces potential resonances. The large bass reflex output is located on the rear wall of the monitor. Assembled from high-quality elements, the crossover is almost perfectly tuned to the phase and amplitude of the signal, thanks to which the resolution of this model is much higher than average.

Sound

The sound of the monitor is characterized by emotional and dynamic playing with excellent transmission of the entire spectrum of instrumental timbres - the localization of sound sources is simply excellent. The sound stage is clean, large-scale and deep, details are worked out to the maximum and do not intertwine, there are practically no extraneous sounds. The high frequencies are characterized by an open sound with a feeling of airiness and, nevertheless, the upper range is very correct and unobtrusive. The bass is clear and fast, with medium depth. In this range there is enough naturalness due to the fact that the feed density “falls” a little. As the volume decreases, the emotionality of the speakers decreases somewhat.

Measurements

With minimal unevenness in the frequency response, a slight frequency imbalance towards high frequencies is noticeable, which, however, is unlikely to affect the tonal balance - we can say that this is not bad at all for budget monitors. Although the total harmonic distortion varies within 1% depending on the volume, there is no noticeable resonance. It should be noted that the SOI margin is good at low frequencies. Impedance is stable.

Martin Logan Motion 15

• Sound: 4
• Construction: 4
• Cost: 3

Advantages:

• the presentation of the material is lively and energetic
• tight and fast bass

Flaws:

• works a little at low volume

The design of this monitor is pleasing to the eye with a filigree finish on the case and a beautiful protective steel grille on the front panel. And underneath it is the highlight - an expensive ultra-high-resolution ribbon tweeter that allows you to produce clear, accurate and dynamic sound. The speaker body is assembled from 19 mm MDF boards, and only the aluminum front panel of the monitor is anodized black, which gives it solemnity and severity. In the same color scheme The diffuser of the midrange/bass driver with a long stroke is also made - the appearance of the speaker is laconic and strict. As for the speakers, their work is coordinated by a crossover with improved characteristics - the manufacturer achieved this effect through the use of polypropylene capacitors and electrolytes with a low loss coefficient. On back panel The speakers have a bass reflex port.

The manufacturer has provided thermal and current protection for the monitor.

Sound

These speakers have one peculiarity: they do not like to work at medium and low volumes - in such cases, only mid frequencies remain in the range, and the dynamics become boring and sluggish. But as the volume increases, the elastic and fast bass “cuts through” more and more clearly, and the upper range becomes clearer. And although the lower middle continues to dominate and does not give way, the music is presented more and more energetically and more sharply. It must be admitted that when the speakers are operating in any volume mode, no extraneous sounds are heard. Moreover, after-sounds sometimes disappear even where they could be. It is worth noting that although this model of “shelf speakers” simplifies the timbres of instruments, a ribbon tweeter with increased sound output helps the situation and gives the mid-upper range a particularly delicate portrayal. Therefore, despite the minor listed errors of the monitor, music lovers appreciate the performance of this speaker.

Measurements

In the high-frequency region, unevenness in the amplitude-frequency response is clearly visible, and the sensitivity towards low frequencies drops quite sharply. The speakers are characterized by a wide directivity. Although the coefficient of nonlinear distortion in the midrange region has slight increases, it still remains below 1%. The impedance is relatively stable.

MK Sound LCR 750

• Sound: 5
• Construction: 5
• Cost: 4

Advantages:

• sound is focused, clear
• good transmission of timbres

Flaws:

• truthfully reflect the shortcomings of studio recording

The laconic design of the speakers from M&K Sound is easily recognizable: strict black color and the absence of even a hint of the slightest decoration. The manufacturer believes that it is much more important to focus on quality, in which the Americans have achieved excellent results - today, among professionals, these acoustic systems have rightfully gained a reputation as the standard of control acoustics. The 750 series, designed for home cinemas, also corresponds to this flattering characteristic, in which the 750 LCR bookshelf monitor stands out with its solid dimensions. The speaker is quite original and stands out even among the models we are considering. Among its main features are the closed housing, due to which bass output is minimized, as well as the installation of two drivers at once - mid- and low-frequency, which significantly increases the dynamic range of the monitor. Another know-how of the manufacturer - a 25 mm silk tweeter installed at an angle of 4.7° to the front plane optimizes the dispersion of various frequencies.

Polypropylene diffusers with mineral filler in combination with the installed phase-focused crossover significantly improved the acoustic parameters of the monitor. For ease of use, the rear panel of the speaker has threaded holes for one or another monitor mounting option.

Sound

With smooth sound, the speakers perfectly control almost any musical material. Almost all instruments are clearly audible on the sound stage, both in timbre and in space. There is nothing superfluous in the overall musical picture, and all dynamic shades are heard clearly. And since the 750 LCR model does not add the slightest emotional coloring, to an unprepared listener this sound may even seem somewhat dry. However, this is how it should be.

Measurements

Deviations in the frequency response of the monitor are so small that there can be no talk of any distortion of the tonal balance. In this case, optimal results were obtained when the column was rotated by 30°. The vanishingly small SOI increases very smoothly towards low frequencies, and only at low volumes reaches 5%. Impedance is stable. In general, we can state a quite good result.

PSB Imagine B

• Sound: 5
• Construction: 5
• Cost: 3

Advantages:

• true transmission of timbres
• smooth dynamics

Flaws:

• limited high frequency range

The basis for why the Canadian company PSB has been successfully selling the Imagine line for several years now was the original design development of the monitors, which made it possible to achieve the extraordinary acoustic parameters of these speakers. And although the originality and elegance of the speakers were duly noted by the prestigious RedDot design award, it was the magnificent specifications. Judge for yourself. In the speaker housing, finished with natural veneer, you will not find right angles - the curved walls of the line’s monitors resemble the bizarre intersection of several cylinders at once, which gives the impression of being “cosmic.” However, at the same time, the design looks strong and solid, and all the bends “work” exclusively to achieve ideal sound, eliminating the appearance of standing waves and the birth of internal resonances. However, the latest technical developments embodied in PSB speakers also contribute to achieving this goal. Let's take a 25mm tweeter for example. Its titanium dome is equipped with an acoustic lens and is cooled by magnetic fluid; the column uses a powerful neodymium magnet. Another effective engineering solution: the polypropylene cone of the midrange/woofer speaker is supplemented with a clay-ceramic filler, which again improves the sound quality. The bass reflex output is located on the rear wall.

Sound

Thanks to such design solutions, the speakers produce a collected and perfectly balanced sound. Monitors are characterized by excellent localization and natural timbres, so the sound stage is perceived almost as if it were alive. Note that even at low volumes the monitors play freely and naturally. True, the high-frequency range is a little limited, which is why the airiness suffers a little. Speaking of detail, it should be noted that sometimes monitors lose the smallest nuances, but even in such cases they delight with the expressiveness and richness of the music. The bass is not very deep, but quite bright. The mid-range is also good - the sound is correct and accurate.

Measurements

Although the frequency response of the monitor runs very smoothly along the acoustic axis, the listener still should not turn the speakers to the side, otherwise the high frequencies will begin to fade. The coefficient of nonlinear distortion throughout the entire range is low and shows stability - right down to the lower frequency limit. Impedance is stable.

Rega RS1

• Sound: 5
• Construction: 4
• Cost: 4

Advantages:

• the upper register is transparent, sounds clean and easy
• wide dynamic range

Flaws:

• the sound is a little colored

The only series of bookshelf monitors RS was developed by the British company Rega specifically to complement other Hi-Fi audio equipment produced by the same manufacturer. Therefore, it is not surprising that the RS1 model we tested incorporated the most interesting solutions premium class, while remaining quite affordable in terms of price. Despite the compactness and small thickness of the panels, the speakers look elegant and rich - primarily thanks to the careful veneer finishing and strict classic design. The drivers, designed and assembled within the company itself, are assembled by hand, and here we can talk about the highest quality of the speakers. Behind the 19mm tweeter is a chamber whose original shape contributes to optimal damping of acoustic waves. The midbass diffuser is made of paper.

Thanks to the smooth frequency operation of the speaker, it can be integrated with a tweeter. To do this, you need a crossover that has good phase synchrony. There is a bass reflex port on the rear panel.

Sound

Although the Rega RS1 speaker conveys tonal nuances quite accurately, due to the barely noticeable coloring, the sound stage loses a little transparency. Again, the upper register is a little missing, although it is completely clean. All the details are heard, but they are also hidden a little. In general, the reproduced material is presented clearly and expansively. Although the bass is reproduced accurately, it does not always have enough weight. In addition, sound localization in the RS1 speakers is a little blurry. But as for complex symphonic music, the monitor does not cope so well, and the sound material becomes more difficult to understand. However, if you listen to music at low volume, the speaker reproduces almost perfectly.

Measurements

In the range of the upper mids and high frequencies, due to the unevenness of the frequency response, the speakers sound slightly different. This can be corrected if the speaker is rotated 30°. Although the coefficient of nonlinear distortion is unstable, this indicator has practically no effect on the sound quality - it is less than one percent. Impedance is unstable.

Triangle Color Bookshelf

• Sound: 5
• Construction: 4
• Cost: 5

Advantages:

• live open sound
• clear transmission of timbres

Flaws:

• some excess bass

As is typical for the French, Triangle has combined the highest quality with grace and elegance in the production of speaker systems. This is most clearly confirmed by the stylish Color line, the speakers of which delight music lovers with an impeccable lacquered finish. The buyer can choose from monitors in colors of red, black and white. Speaking about the Bookshelf bookshelf, first of all we should note its tweeter with a titanium membrane and coated special composition paper diffuser for mid/bass speakers. The originality of the speaker is complemented by a fabric and wide corrugated suspension, as well as a dust cap made in the shape of a bullet. The crossover uses effective technologies that once pleased Magellan's top line - now the bookshelf also has this know-how. Let us add that the bass reflex output is located on the rear panel of the speaker.

Sound

The monitor produces very lively and natural sound with very high timbre accuracy. The reproduction of sound material is relaxed and natural.

The power of musical sound recreates a live performance remarkably accurately. The bass is well-formed and pleasantly deep. Sometimes it seems that there is even too much of it. The sound is very clear and detailed – the slightest nuances do not escape the listener. The speakers of this model perfectly reproduce compositions of any complexity, and even at low volumes the sound quality does not deteriorate.

Measurements

The imbalance in the frequency response detected in the high-frequency range is eliminated traditionally - it is enough to turn the column by 30°. The nonlinear distortion factor is quite low, but at mid frequencies it becomes higher, although it does not exceed 1%. At high volumes, distortion in the upper bass is noticeable. Impedance is unstable.

Wharfedale Jade 3

• Sound: 3
• Construction: 3
• Cost: 4

Advantages:

• good attention to detail

Flaws:

• the dynamics are a little weakened
• inaccurate localization

What sets the British company Wharfedale apart is its meticulous approach to the production of budget lines. For example, to the Jade 3 model, the only three-way monitor in our test. But if other manufacturers classify large and heavy monitors with curved panels as top brands, the British chose this form for the bookshelf solely for pragmatic reasons - auxiliary bulkheads dampen unwanted resonance inside the sealed case and minimize harmful sound coloration. At the border of 3 kHz, the tweeter with an aluminum dome neatly gives way to the midrange driver, whose diffuser is made of an aluminum-cellulose composite. And already in the range of 350 Hz, the main dynamic load passes to the low-frequency speaker, which is equipped with a woven diffuser made of reinforced fabric consisting of carbon and fiberglass threads. It is pertinent to note here that this combination of materials turns the diffuser into a flawless piston, which eliminates the unwanted resonance phenomena characteristic of metal diffusers. Let us add that the speaker speakers operate in a sealed volume, and the ideal linearity of the crossover phase signal is the result of computer optimization.

Sound

According to the established corporate tradition, all Wharfedale monitors sound equally beautiful. Everything in the acoustic space musical instruments are clearly placed in their places, and the soundstage is clean and spacious. The speakers produce bass, as well as the upper register, carefully, non-aggressively, as if afraid to upset the balance of the reproduced sound picture. This model is characterized by a combination of soft presentation of sound images with optimal sound detail. It is worth noting that the monitor behaves very well even at low volumes.

Measurements

The amplitude-frequency response of the speaker is almost perfectly flat, but in the upper range it behaves unusually: after an unexpected decline, a sharp rise is immediately recorded. The bass range is quite deep. The nonlinear distortion coefficient is pleasing: at all ranges it is almost exclusively smooth and as low as possible. The low frequency range shows a solid margin. The impedance is quite stable.

conclusions

Comparing the results of speaker measurements in our test laboratory, we came to the conclusion that comparing bookshelf speakers is not as interesting as in the past. All tested monitors showed almost identical, even amplitude-frequency characteristics with minor deviations that did not affect perception, as well as a very low coefficient of nonlinear distortion, which again did not go into the critical zone even in the bass region. Not surprising, since there are practically no speaker manufacturers left who do not use computer tools modeling, and this is a guarantee of high quality! Again, no matter what the body shape of the speakers we tested, we did not notice any serious distortions, because every manufacturer now has the ability to correctly calculate damping elements. As a result, the design of all tested speakers was rated quite highly.

True, two models still need to be noted - MK Sound LCR 750 and Dynaudio DM 2/7. Initially, manufacturers aimed these developments, like their previous lines, at the professional acoustics market, focusing on maximum accuracy in transmitting musical material. They achieved their goal: the named models are bookshelf acoustics, designed at a professional level. This means that these speakers sound neutral and even seem “dry”, but this is precisely one of the most important requirements from professionals - not the slightest “embellishment”!

And if we are talking about beautiful and comfortable sound, we note that most of the tested monitors meet these criteria perfectly. Most of the speakers tested have such features as accurate sound localization, accuracy in the transmission of timbres, well-defined bass - everything that is so valued by true music lovers. Based on the test results, it is worth noting the main advantages of bookshelf speakers: dense, rich sound from PSB Imagine B, accurate presentation of material from Canton Chrono 503.2, open airy image from Rega RS1, defiantly aggressive pressure from MartinLogan Motion 15. However, there are no winners. Therefore, we give the palm of our test to

Speaker system (General concepts and frequently asked questions)

1. What is an acoustic system (AS)?

This is a device for effective radiation of sound into the surrounding space in the air, containing one or more loudspeaker heads (SG), the necessary acoustic design (AO) and electrical devices, such as transition filters (PF), regulators, phase shifters, etc. See also: on our website.

2. What is a loudspeaker head (HL)?

This is a passive electro-acoustic transducer designed to convert signals audio frequency from electric to acoustic form.

3. What is a passive converter?

This is a converter that does NOT increase the energy of the electrical signal entering its input.

4. What is acoustic design (AO)?

This is a structural element that ensures effective radiation of GG sound. In other words, in most cases, the AO is the speaker body, which can take the form of an acoustic screen, box, horn, etc.

5. What is a single-way speaker?

Essentially the same as broadband. This is a speaker system, all of whose main generators (usually one) operate in the same frequency range (i.e., filtering of the input voltage using a filter, as well as no filters themselves).

6. What is a multi-way speaker?

These are speakers whose main generators (depending on their number) operate in two or more different frequency ranges. However, directly counting the number of GGs in the speakers (especially those released in previous years) may not say anything about the real number of bands, since several GGs can be allocated to the same band.

7. What are open speakers?

This is an AS in which the influence of air elasticity in the volume of the AO is negligible, and the radiation from the front and rear sides of the moving GG system is not isolated from each other in the LF region. It is a flat screen or box, the back wall of which is either completely absent or has a number of through holes. The greatest influence on the frequency response of speakers with open-type AO is exerted by the front wall (in which the GGs are mounted) and its dimensions. Contrary to popular belief, the side walls of an open-type AO have very little effect on the characteristics of the speaker. Thus, it is not the internal volume that is important, but the area of ​​the front wall. Even with its relatively small size, bass reproduction is significantly improved. At the same time, in the midrange and, especially, high-frequency regions, the screen no longer has a significant effect. A significant disadvantage of such systems is their susceptibility to acoustic “short circuit”, which leads to a sharp deterioration in low frequency reproduction.

8. What are closed-type speakers?

This is an AS in which the elasticity of the air in the volume of the AO is commensurate with the elasticity of the moving GG system, and the radiation from the front and rear sides of the movable GG system is isolated from each other over the entire frequency range. In other words, this is a speaker whose housing is hermetically sealed. The advantage of such speakers is that the rear surface of the diffuser does not radiate and, thus, there is no acoustic “short circuit” at all. But closed systems have another drawback - when the diffuser oscillates, it must overcome the additional elasticity of the air in the AO. The presence of this additional elasticity leads to an increase in the resonant frequency of the moving system of the GG, as a result of which the reproduction of frequencies below this frequency deteriorates.

9. What is a speaker with a bass reflex (FI)?

Striving to get enough good reproduction LF with a moderate volume of AO is achieved quite well in so-called phase-inverted systems. In the AO of such systems a slot or hole is made into which a tube can be inserted. The elasticity of the volume of air in the joint resonates at some frequency with the mass of air in the hole or tube. This frequency is called the PI resonant frequency. Thus, the AS as a whole becomes consisting of two resonant systems - the moving system of the GG and the AO with a hole. With the correctly selected ratio of the resonant frequencies of these systems, the reproduction of low frequencies is significantly improved compared to a closed-type AO with the same volume of AO. Despite the obvious advantages of speakers with FI, very often such systems, made even by experienced people, do not give the results expected from them. The reason for this is that in order to obtain the desired effect, FI must be correctly calculated and configured.

10. What is bass-reflex?

Same as FI.

11. What is a crossover?

Same as a transition or crossover filter.

12. What is a transition filter?

This is passive electrical diagram(usually consisting of inductors and capacitors), which is turned on before the input signal and ensures that each GG in the speaker is supplied with voltage only at the frequencies that they must reproduce.

13. What are the “orders” of transition filters?

Since no filter can provide absolute voltage cutoff at a given frequency, the PF is designed at a specific crossover frequency, beyond which the filter provides a selected amount of attenuation, expressed in decibels per octave. The amount of attenuation is called slope and depends on the design of the PF. Without going into too much detail, we can say that the simplest filter - the so-called first-order PF - consists of just one reactive element - capacitance (cut off the low frequencies if necessary) or inductance (cut off the high frequencies if necessary) and provides a slope of 6 dB/oct. Twice the steepness - 12dB/oct. - provides a second-order PF containing two reactive elements in the circuit. Attenuation 18dB/oct. provides a third-order PF containing three reactive elements, etc.

14. What is an octave?

In general, this is doubling or halving the frequency.

15. What is the AC working plane?

This is the plane in which the emitting holes of the GG AS are located. If the GG of a multi-band speaker are located in different planes, then the one in which the emitting holes of the HF GG are located is taken as the working one.

16. What is an AC work center?

This is a point lying on the working plane from which the distance to the speaker is measured. In the case of single-way speakers, the geometric center of symmetry of the radiating hole is taken as it. In the case of multi-band speakers, it is taken to be the geometric center of symmetry of the emitting holes of the HF main generator or the projections of these holes onto the working plane.

17. What is the AC working axis?

This is a straight line passing through the working center AC and perpendicular to the working plane.

18. What is the nominal impedance of the speakers?

This is specified in technical documentation active resistance, which replaces the impedance module of the speaker when determining the electrical power supplied to it. According to the DIN standard, the minimum value of the speaker impedance module in a given frequency range should not be less than 80% of the nominal.

19. What is the impedance of speaker systems (AS)?

Without delving into the basics of electrical engineering, we can say that impedance is the TOTAL electrical resistance of the speaker (including both crossovers and main generators), which in the form of a rather complex dependence includes not only the familiar active resistance R (which can be measured with a regular ohmmeter), but also and reactive components represented by capacitance C (capacitance, depending on frequency) and inductance L (inductive reactance, also dependent on frequency). It is known that impedance is a complex quantity (in the sense of complex numbers) and, generally speaking, is a three-dimensional graph (in the case of speakers it often looks like a “pig tail”) in amplitude-phase-frequency coordinates. It is precisely because of its complexity that when they talk about impedance as a numerical value, they talk about its MODULE. Of greatest interest from the point of view of research are the projections of the “pig’s tail” onto two planes: “amplitude-from-frequency” and “phase-from-frequency”. Both of these projections, presented on the same graph, are called “Bode plots”. The third amplitude-versus-phase projection is called the Nyquist plot. With the advent and proliferation of semiconductors, audio amplifiers began to behave more or less like sources of “constant” voltage, i.e. they, ideally, should maintain the same voltage at the output, regardless of what load is placed on it and what the current demand is. Therefore, if we assume that the amplifier driving the GG speaker is a voltage source, then the impedance of the speaker will clearly indicate what the current consumption will be. As already mentioned, impedance is not only reactive (that is, characterized by a non-zero phase angle), but also changes with frequency. Negative phase angle, i.e. when the current leads the voltage, due to the capacitive properties of the load. A positive phase angle, i.e. when the current lags behind the voltage, is due to the inductive properties of the load.
What is the impedance of typical speakers? The DIN standard requires that the impedance of the speaker does not deviate from the specified rating by more than 20%. However, in practice, everything is much worse - the deviation of the impedance from the rating is on average +/-43%! As long as the amplifier has a low output impedance, even such deviations will not introduce any audible effects. However, as soon as the game is introduced TUBE amplifier with an output impedance of the order of several Ohms (!), the result can be very disastrous - coloration of the sound is inevitable.
Speaker impedance measurement is one of the most important and powerful diagnostic tools. An impedance graph can tell you a lot about what a given speaker is like without even seeing or hearing it. Having an impedance graph in front of your eyes, you can immediately tell what type of speaker the data is - closed (one hump in the bass area), bass reflex or transmission (two humps in the bass area), or some type of horn (a sequence of evenly spaced peaks). You can judge how well the bass (40-80Hz) and the lowest bass (20-40Hz) will be reproduced by certain speakers by the shape of the impedance in these areas, as well as by the quality factor of the humps. The “saddle” formed by two peaks in the low-frequency region, typical of a bass reflex design, indicates the frequency to which the bass reflex is “tuned”, which is usually the frequency at which the low-frequency response of the bass reflex drops by 6 dB, i.e. approximately 2 times. From the impedance graph you can also understand whether there are resonances in the system and what their nature is. For example, if you carry out measurements with sufficient frequency resolution, then perhaps some kind of “notches” will appear on the graph, indicating the presence of resonances in the acoustic design.
Well, perhaps the most important thing that can be taken away from the impedance graph is how heavy this load will be for the amplifier. Since the AC impedance is reactive, the current will either lag behind the signal voltage or lead it by a phase angle. In the worst case, when the phase angle is 90 degrees, the amplifier is required to deliver maximum current while the signal voltage approaches zero. Therefore, knowing the “passport” 8 (or 4) Ohms as a nominal resistance does NOT give anything at all. Depending on the phase angle of the impedance, which will be different at each frequency, certain speakers may be too tough for one or another amplifier. It is also very important to note that MOST amplifiers DO NOT seem to us to be unable to handle speakers simply because at TYPICAL volume levels acceptable in TYPICAL home environments, TYPICAL SPEAKERS DO NOT require more than just a few Watts to be "powered" by a TYPICAL amplifier.

20. What is the rated power of the GG?

This is a given electrical power at which the nonlinear distortions of the GG should not exceed the required ones.

21. What is the maximum noise power of the GG?

This is the electrical power of a special noise signal in a given frequency range, which the generator can withstand for a long time without thermal and mechanical damage.

22. What is the maximum sinusoidal power of the GG?

This is the electrical power of a continuous sinusoidal signal in a given frequency range, which the GG can withstand for a long time without thermal and mechanical damage.

23. What is the maximum short-term power of the GG?

This is the electrical power of a special noise signal in a given frequency range, which the GG can withstand without irreversible mechanical damage for 1 s (tests are repeated 60 times with an interval of 1 min.)

24. What is the maximum long-term power of the GG?

This is the electrical power of a special noise signal in a given frequency range, which the GG can withstand without irreversible mechanical damage for 1 minute. (tests are repeated 10 times with an interval of 2 minutes)

25. All other things being equal, speakers with what nominal impedance is more preferable - 4, 6 or 8 Ohms?

In general, a speaker with a higher nominal impedance is preferable, since such a speaker represents a lighter load for the amplifier and, therefore, is much less critical to the choice of the latter.

26. What is the impulse response of speakers?

This is her response to the “ideal” impulse.

27. What is an “ideal” impulse?

This is an instantaneous (rise time equal to 0) increase in voltage to a certain value, “stuck” at this constant level for a short period of time (say, a fraction of a millisecond) and then an instantaneous decrease back to 0V. The width of such a pulse is inversely proportional to the signal bandwidth. If we wanted to make a pulse infinitely short, then in order to transmit its shape completely unchanged, we would need a system with an infinite bandwidth.

28. What is the transient response of speakers?

This is its response to a “step” signal. The transient response gives a visual representation of the behavior of all GG AS over time and allows one to judge the degree of coherence of the AS radiation.

29. What is a step signal?

This is when the voltage at the input to the AC instantly increases from 0V to some positive value and remains so for a long time.

30. What is coherence?

This is the coordinated occurrence of several oscillatory or wave processes in time. In relation to speakers, it means the simultaneous arrival of signals from different GGs to the listener, i.e. actually reflects the fact of preservation of the phase integrity of information.

31. What is GG polarity?

It's a certain polarity electrical voltage on the terminals of the GG, causing the movement of the movable system of the GG in a given direction. The polarity of a multiband speaker is determined by the polarity of its LF GG.

32. What is a GG connection in absolute positive polarity?

This is connecting the GG to a voltage source in such a way that when an electric voltage of positive polarity is applied to it, the coil moves forward from the magnet gap, i.e. air compression takes place.

33. What is the frequency response of AC?

This is the amplitude-frequency characteristic, i.e. dependence on the frequency of the sound pressure level developed by the speaker at a certain point in the free field, located at a certain distance from the working center (usually 1 m).

34. What is polar characteristic?

This is a graphical dependence under free field conditions of the sound pressure level (for a given frequency band and distance from the working center of the GG) on the angle between the working axis of the GG and the direction to the measurement point.

35. What conventional parts is the frequency range divided into for convenience of verbal description?

• 20-40Hz - lower bass
• 40-80Hz - bass
• 80-160Hz - upper bass
• 160-320Hz - lower midbass
• 320-640Hz - midbass
• 640-1.280Hz - upper midbass
• 1.28-2.56kHz - lower middle
• 2.56-5.12kHz - middle
• 5.12-10.24 kHz - upper mid
• 10.24-20.48 kHz - top

36. What are the names of the variable regulators that can be seen on some speakers?

Attenuators. They are sometimes called acoustic equalizers.

37. What is the purpose of attenuators?

Depending on the calibration, increase and/or decrease the voltage supplied to one or another GG, which, accordingly, leads to an increase and/or decrease in the sound pressure level in a certain frequency range. Attenuators do not make changes to the shape of the frequency response of individual generators, but they change the GENERAL appearance of the frequency response of the speakers by “raising” or “lowering” certain parts of the spectrum. In some cases, attenuators allow, to one degree or another, to “adapt” the speakers to specific listening conditions.

38. What is speaker sensitivity?

Speaker sensitivity is often and widely confused with efficiency. Efficiency is defined as the ratio of the ACOUSTIC power supplied by the speakers to the ELECTRICAL power consumed. Those. the question is formulated as follows: if I put 100 electrical watts into the speaker, how many acoustic (sound) watts will I get? And the answer to it is “a little, a little.” The efficiency of a typical moving coil generator is about 1%.
Efficiency is usually given in the form of the sound pressure level generated by the speaker at a given distance from the operating center of the speaker with an input power of 1 W, i.e. in Decibels per Watt per meter (dB/W/m). However, knowledge of this value cannot be called useful, since it is extremely difficult to determine what the input power of 1 W is for these specific speakers. Why? Because there is a dependence on both impedance and frequency. Give a speaker with an impedance of 8 Ohms at 1 kHz a signal of the same frequency and a level of 2.83 Volts, and yes, without a doubt, you will power the speaker with a power of 1 W (according to Ohm's law, “power” = “voltage squared” / “resistance” "). And here a big “BUT” comes up - not only is the speaker impedance inconsistent and depends on frequency, but at lower frequencies it can decrease dramatically. Let's say up to 2 ohms at 200 Hz. Having now powered the speakers with the same 2.83 Volts, but at a frequency of 200 Hz, we will thereby require the amplifier to give us 4(!) times more power. For the same sound pressure level, speakers at 1 kHz are four times more efficient than speakers at 200 Hz.
Why does efficiency matter at all? If half a century ago audio engineers were very concerned about the problem of power transfer (and telecommunications engineers are still interested in this today!), then with the advent of semiconductor devices, audio amplifiers began to behave more or less like “constant” voltage sources - they support the same output voltage regardless of what load is placed on it and what the current consumption is. That is why it is NOT EFFICIENCY that comes to the fore, but voltage SENSITIVITY, i.e. how loud the speaker plays at a given amplifier output voltage. Voltage sensitivity is usually defined as the sound pressure level developed by the speaker at a distance of 1 meter from the operating center of the speaker at a terminal voltage of 2.83 Volts (i.e., the voltage required to dissipate 1 Watt into an 8-ohm resistor).
The advantage of specifying sensitivity instead of efficiency is that it always remains constant regardless of speaker impedance, since the amplifier is assumed to always be able to supply enough current to maintain 2.83 volts. The closer the speaker impedance module approaches that of a pure 8-ohm resistor, the higher the degree of equivalence of these two criteria. However, in the case when the speaker impedance differs significantly from 8 Ohms, the benefit of knowing the efficiency is reduced to nothing.
The voltage sensitivity of the speakers is important, in particular, when selecting the “amplifier - speaker” pair. If you have a 20W amplifier, you better think hard about speakers with VERY high sensitivity, because otherwise you will never listen to loud music. And conversely, if you take a speaker with a sufficiently high sensitivity - say, 100 dB / 2.83V / m, then it may turn out that a 5-watt amplifier is enough for your eyes in the sense that spending $ 10,000 on an amplifier with a power of 600 Watts with such speakers would be a waste of money.
However, despite the fact that it is completely obvious to everyone that voltage sensitivity is a more than important parameter of the speaker system, many people still do not want to consider it properly. The problem is that speakers tend to have an uneven frequency response, and therefore finding the peak value among all its slabs and making statements like “Since the speaker plays the loudest at this frequency, that means this is the sensitivity!” is for the marketing departments of companies. , producing AS, THE GREAT TEMPTATION.
So what is the actual sensitivity of typical speakers? It turns out that it is about 85-88 dB/2.83V/m. The share of such speakers is about 40%. It is curious that speakers with low sensitivity (less than 80) are mainly panel speakers of all kinds, and speakers with high sensitivity (more than 95) are professional monitors. And this is not surprising. Achieving great sensitivity requires heroic engineering efforts, which, of course, ALWAYS come at a cost. And the vast majority of speaker designers are constrained by BUDGET limits, which only means that they will ALWAYS look for compromises, saving on the size of magnets, the shape of moving coils and diffusers.
It is also worth noting that the actually measured sensitivity is ALWAYS LESS than that indicated by the manufacturer in the documents. Manufacturers are always too optimistic.

39. Do I need to install speakers on spikes?

Very desirable.

40. What are the thorns for?

In order to minimize the transmission of vibration from the acoustic design of the speaker to objects in contact with it (room floors, shelves, for example). The effect of using spikes is based on a radical reduction in the area of ​​contacting surfaces, which is reduced to the area of ​​the tips of the spikes/cones. It is important to understand that installing speakers on spikes does NOT eliminate cabinet vibrations, but only reduces the efficiency of their further propagation.

41. Does the location of the spikes under the speaker matter?

The most unfavorable support for the speaker is to install it on 3 (three) metal spikes/cones, one of which is placed in the middle at the rear wall, and the other two are located at the two front corners. This arrangement of the speakers “gives free rein” to almost ALL body resonances.

42. How to minimize cabinet resonances of speakers?

The most IN THE BEST WAY To reduce the cabinet resonances of the speakers, due to how and on what they are installed, is to use a vibration-absorbing material such as dense padding polyester as a gasket.

43. In what cases is the use of bi-wiring/bi-amping justified?

Bi-wiring does NOT have any basis physical basis and, as a result, has NO audible effect, and therefore is absolutely meaningless.
Bi-amping comes in two types: false and literate. You can see what this means. Despite the existence of physical validity of the application, the effect of bi-amping is vanishingly small.

44. Does the external finish of the speakers (vinyl film, natural veneer, powder paint, etc.) affect the sound?

No, it does NOT affect the sound in any way. Only for the PRICE.

45. Does the interior finishing (foam rubber, mineral wool, padding polyester, etc.) of the speaker affect the sound?

The purpose of ANY "stuffing" of speakers with anything is the desire or need to suppress standing waves that arise inside any acoustic design, the presence of which can seriously degrade the characteristics of the speaker. Therefore, the entire “influence” of interior finishing on sound comes down to how well this finishing prevents the occurrence of standing waves. The presence of internal resonances can be assessed, for example, by the results of impedance measurements carried out with high resolution by frequency.

46. ​​Do grills, as well as other decorative frames of the front panels of speakers or individual GGs (for example, metal mesh) affect the sound?

Strictly speaking, YES, they do. And in most cases this can be seen with your own eyes during measurements. The only question is, can it still be heard? In some cases, when this influence exceeds 1dB, it is quite possible/real to hear it in the form of some “roughness” in the sound, usually in the HF region. The influence of fabric “scenery” is minimal. As the rigidity of the “scenery” increases (especially for metal products), the degree of visibility increases.

47. Are there any real benefits to speakers with rounded corners?

There are none.

48. Special shape of dust caps on speakers - necessity or decoration?

The answer can only be speculative. Nowadays, when laser vibrometry is (or CAN be used) used to monitor the "behavior" of the diaphragm surface during reciprocating movement, it may well be that the shape of the caps is NOT chosen at random and NOT for beauty, but to optimize the performance of the diaphragm in the piston mode. In addition, dust caps in some cases help level out the frequency response (usually in the 2-5 kHz region).

49. What is piston mode?

This is a mode in which the ENTIRE surface of the GG diffuser moves as one.
It is very convenient to explain this concept using the example of a broadband GG. In the low-frequency region, the rate of change in the phase of the signal in the voice coil is less than the speed of propagation of mechanical excitation in the diffuser material, and the latter behaves as a single whole, i.e. vibrates like a piston. At these frequencies, the frequency response of the GG has a smooth shape, which indicates the absence of partial excitation of individual sections of the diffuser.
Usually, GG developers strive to expand the area of ​​piston action of the diffuser towards the HF by giving a special shape to the cone generatrix. For a properly designed cellulose cone, the area of ​​piston action can be approximately defined as a sound wavelength equal to the circumference of the cone at the base of the cone. At medium frequencies, the rate of change in the phase of the signal in the voice coil exceeds the speed of propagation of mechanical excitation in the diffuser material and bending waves arise in it; the diffuser no longer vibrates as a single whole. At these frequencies, the damping rate of mechanical vibrations in the diffuser material is still not high enough and the vibrations, reaching the diffuser holder, are reflected from it and propagate through the diffuser back towards the voice coil.
As a result of the interaction of direct and reflected vibrations in the diffuser, a picture of standing waves arises, and areas with intense antiphase radiation are formed. At the same time, sharp irregularities (peaks and dips) are observed in the frequency response, the range of which can reach tens of dB in a non-optimally designed diffuser.
At HF, the attenuation rate of mechanical vibrations in the diffuser material increases and standing waves are not formed. Due to the weakening of the intensity of mechanical vibrations, high-frequency radiation occurs predominantly in the diffuser area adjacent to the voice coil. Therefore, to increase HF reproduction, horns are used, attached to a moving GG system. To reduce the unevenness of the frequency response, various damping (increasing the attenuation of mechanical vibrations) additives are added to the mass for the manufacture of GG diffusers.

50. Why do most speakers generally use several GGs (two or more)?

First of all, because high-quality sound radiation in different parts of the spectrum places too different demands on the GG, which a single GG (broadband) is not able to fully satisfy, at least purely physically (in particular, see the previous paragraph). One of the key points is a significant increase in the directivity of the radiation of any GG with increasing frequency. Ideally, the gas generators in the system should not only operate in piston mode, which, generally speaking, entails a sharp increase in the total number of gas generators in the system (and, accordingly, an increase in the number of transition filters, which automatically causes a sharp increase in the complexity and cost of the product), but also be characterized by omnidirectional radiation, which is only possible under the condition that the linear size of the GG is much LESS than the wavelength of the radiation it emits. Only in this case will the GG have good dispersion.
As long as the frequency is low enough, this condition is satisfied and the GG is omnidirectional. With increasing frequency, the radiation wavelength decreases and, sooner or later, becomes COMPARABLE to the linear dimensions of the GG (diameter). This, in turn, leads to a sharp increase in the directivity of the radiation - the GG eventually begins to emit like a spotlight, straight forward, which is completely unacceptable. Let's take, for example, a burdock bass with a diameter of 30 cm. At a frequency of 40 Hz, the wavelength of the radiation is 8.6 m, which is 28 times greater than its linear size - in this area such a woofer is omnidirectional. At a frequency of 1,000 Hz, the wavelength is already 34 cm, which is already literally COMPARABLE to the diameter. At this frequency, the dispersion of such a bass driver will be radically worse, and the radiation will be extremely directional. Traditional two-way speakers with a transition frequency in the region of 2-3 kHz - which corresponds to wavelengths of 11-17 cm - are equipped with woofers with linear dimensions of exactly the same order, which leads to a SHARP deterioration in the polar characteristics of the speakers in the specified area, which has the shape of a dip or gorge. The failure is due to the fact that while the LF of the GG in a given area becomes highly directional, the tweeter (usually 1.5-2 cm in diameter) in the same area is almost omnidirectional.
In particular, this is why good THREE-WAY speakers are always BETTER than good TWO-WAY speakers.

51. What is variance?

In this context, the same as "emissivity in different directions."

52. What is a radiation pattern?

Same as polar characteristic.

53. What is frequency response unevenness?

This is the difference (expressed in dB) between the maximum and minimum sound pressure levels in a given frequency range. You can often read in the literature that the peaks and troughs of the frequency response already 1/8 octave are not taken into account. However, this approach is not progressive, since the presence of serious peaks and dips in the frequency response (even narrow ones) indicates poor quality of the diffuser, the presence of standing waves in it, i.e. about the shortcomings of the GG.

54. Why are the heads in speakers sometimes turned on in different polarities?

Since transition filters in ANY case change (or, as they say, rotate) the phase of the input signal - the higher the order of the filter, the greater the phase shift - then in some cases the situation develops in such a way that in the transition zone signals from different GGs “meet” in out of phase, which leads to serious distortions in the frequency response, which look like steep dips. Switching on one of the GGs in a different polarity leads to the fact that the phase is reversed by another 180 degrees, which often has a beneficial effect on equalizing the frequency response in the transition zone.

55. What is cumulative spectrum attenuation (CSF)?

This is a set of axial frequency response of the speaker, obtained with a certain time interval during the attenuation of a single pulse applied to it, and displayed on one three-dimensional graph. Since, being an electromechanical system, the speaker is an “inertial” device, the oscillatory processes continue for some time even after the termination of the pulse, gradually fading over time. Thus, the graph of the cumulative attenuation of the spectrum clearly shows which areas of the spectrum are characterized by increased post-pulse activity, i.e. allows you to identify the so-called delayed resonances of the speakers.
The “cleaner” the ECG graph of speakers looks in the region above 1 kHz, the higher the chance that such speakers will be subjectively assessed by listeners as distinguished by “great transparency,” “lack of graininess,” and “sound purity.” Conversely, speakers that are said to sound “grainy” or “harsh” are almost 100% likely to have a strong “ridged” GSV graph (although, of course, factors such as non-linear distortion and frequency imbalance can also play a role your role).

56. What are the names of the peculiar dividers of bizarre shape or geometry that are placed on top of some GGs?

Phase shifters, deflectors, acoustic lenses.

57. Why are phase shifters used?

In any case, not for beauty, but for the supposed improvement of the dispersion characteristics of the speaker.

58. Does the material from which the GG diffuser is made (silk, metal, paper, polypropylene, Kevlar, carbon, composite, etc.) have any effect on the sound?

In the sense that, depending on the material used, can the sound be “silk”, “paper”, “plastic”, “metal” and all sorts of other things, then the answer is NO, it cannot. The material of a well-designed diffuser does NOT have any effect on the sound in the DIRECT sense. So what is the point of using DIFFERENT materials in the manufacture of diffusers? The point is that any competent developer strives, in fact, for only one goal: to use a material for the production of diffusers that would simultaneously satisfy the following requirements: it would be rigid, light, durable, well damped, inexpensive and, most importantly, easy replicable, especially for mass production purposes. In the context of column construction, all the materials listed above (as well as all sorts of others not included in the list) differ from each other only in the characteristics and properties just listed. And this difference, in turn, affects only and exclusively approaches to reducing the audible sound coloration that appears due to resonances arising in the diaphragms.

59. Is it true that good, “real” bass can only be obtained from speakers with large mug bass drivers, 30 centimeters in diameter?

No that's not true. The quantity and quality of bass depend very little on the size of the woofer.

60. What then is the meaning of big mug bass players?

A large woofer has a larger surface area and therefore moves a larger mass of air than a smaller woofer. Consequently, the sound pressure developed by such a bass driver is also greater, which directly affects the sensitivity - speakers with large bass drivers, as a rule, have very high sensitivity (usually above 93dB/W/m).

12/25/2005 Globalaudio

Let's imagine a person who is interested in music, but has never paid attention to sound quality. And so, having heard a lot about Hi-Fi and High-End technology, he decides to check for himself what “real sound” is. As a rule, he doesn’t have much money, and it’s a pity to spend it on what he doesn’t yet know. Our test of bookshelf speakers will be very useful for just such a person, and it is in this price range that you can find speakers that can demonstrate true Hi-Fi sound quality. Yes, you will have to make a small allowance for the bass depth. But, on the other hand, bookshelf acoustics, as a rule, play better at low volumes than floor-standing ones, and it will be easier to place them in the room. A dozen speakers - a wide choice. I am sure that among them there will be very, very worthy specimens.

Criteria for evaluation

We are dealing with classic workhorses, and the approach to testing is quite traditional. The frequency response and SOI will show us how flawlessly the speaker design is made from a technical point of view. Together with design features model, this will constitute a design assessment.
Listening will make its own adjustments and will reveal the sound character of the speakers. Good bass depth and high quality are rarely combined in the bookshelf format, so we won’t be too strict about this parameter. But having a clean and even upper register is quite possible for small speakers. The importance of this parameter is extremely important for the natural presentation of musical material. High quality sound at low volumes is also important and is an indicator of smooth, almost linear speaker dynamics. Timbral fidelity will allow you to enjoy the full beauty of the sound of each individual instrument. After all, musical instruments are created in order to enjoy their sound, and not to try to understand what exactly is playing. All this will add up to a sound rating. The last assessment is inversely proportional to the price: higher the price - lower the assessment.

Acoustic Energy 301

Sound: 4
Construction: 4
Price: 4
Advantages:
- High detail
- Timbral fidelity
Flaws:
- Not enough air

When developing the 300 series, the designers achieved visual minimalism. From appearance all excluded small parts like screws, grill mounts. The front wall of the speaker is finished with a black rubber-like coating that matches the color of the driver diffusers. The finishing of the speakers is also minimalistic - black or white varnish. Model 301 houses a proprietary 28 mm fabric dome tweeter and a traditional, well-recognized midrange/bass driver with a cone made of bent, heavily anodized aluminum with a diameter of 110 mm. This speaker is a distant legacy of the legendary AE1 monitors.

Bookshelf acoustics Acoustic Energy 301

It is curious that the company decided to use a slotted bass reflex port located on the front panel. It was possible to save the size of the column while placing it conveniently near the wall.

Sound
The absence of any noticeable sound color allows the speaker to unfold and, even when playing rather restrainedly, present musical compositions in an interesting way. The smallest details are clearly visible, and the timbres are very close to natural. The entire frequency scale is well balanced both in level and dynamics - the sound is holistic.

Upper register intelligibility is not bad, but it is a little lacking for an open sound with enough air. On complex compositions, the intelligibility of musical material decreases. At low volumes the sound character remains almost unchanged.

Measurements

The frequency response is very smooth. The decline in the low-frequency region is uniform. Bass is medium deep. The THD is quite low right down to the very bottom and is practically independent of the volume level. Impedance is unstable.

Bowers & Wilkins 685

Sound: 4

Construction: 5

Price: 5

Advantages:

- Spacious sound

- Fast bass

Flaws:

- Slight simplification of timbres

The model represents the junior line of Bowers & Wilkins. Possessing a laconic modern design, the line nevertheless inherited some technologies from the flagships themselves. Of course, this only applies to inexpensive and effective solutions such as Nautilus tweeter tubes, Kevlar cones and a golf ball bass reflex port. The aluminum dome tweeter is surrounded by a special material that helps achieve spacious sound. The midrange/woofer uses a static bullet to smooth out the response at the upper end of frequencies.

Bookshelf speakers Bowers & Wilkins 685

The crossover of the model is minimized as much as possible - it is of the first order. The speaker body is finished with film, and the front panel is covered with a velvety material that is pleasant to the touch.

Sound
The sound of the model is open and bright. Detail is at a good level. The bass is collected and fast. Localization is clear. Impressive dynamic range.

Instrument timbres are slightly simplified at mid frequencies. In this case, the upper register region is very active.

It adds airiness and spaciousness to the sound. The model is characterized by increased emotionality and expressiveness.

Measurements

There are noticeable irregularities in the region of 2.5 kHz and 6-7 kHz, which disappear when the speaker is rotated 30°. However, the frequency balance shifts slightly to the low-frequency region. SOI is extremely low. The impedance is extremely unstable.

Canton Chrono 503.2

Sound: 4

Construction: 5

Price: 5

Advantages:

- Clean uppercase

- Accurate reproduction of timbres

Flaws:

- Bass is weak at low volumes

Chrono 503.2 is a real German speaker: excellent workmanship, 100% quality control of each copy, Made in Germany. Despite the stated glossy finish, the speaker is covered with film, and only the front panel is made glossy. The size of the speaker is not very large, but the speaker managed to accommodate an impressive 180 mm. Of course, it is equipped with the traditional Canton aluminum diffuser. The suspension is made in the shape of a wave for the most linear and long piston stroke of the diffuser. The 25mm tweeter dome is made from a very lightweight but durable aluminum and magnesium alloy. For reliability, it is protected by a metal grill. There are two threaded holes on the bottom for mounting on a stand or bracket.

Bookshelf speakers Canton Chrono 503.2

Sound
The musical material is presented very carefully. The frequency balance is almost perfect. The timbres of instruments are transmitted with high reliability, and small details are not lost sight of. There is no increased emotionality, but thanks to a wide and smooth dynamic range, the speakers manage to accurately convey the musical idea of ​​the composition. The bass is collected, neat, exactly in its place. However, it is not very deep, and at low volumes it loses its position even more. At first it seems that there are too many high frequencies, but they appear exactly when you really need them, and in the right quantities. The upper register is very clean, which fans of modern electronic music will certainly appreciate.

Measurements

The frequency response is smooth, although it depends quite strongly on the listening angle - the directivity of the speakers is relatively narrow. The THD is very low and there is good headroom at low frequencies. Impedance is unstable.

Chario Syntar 516

Sound: 3

Construction: 4

Price: 4

Advantages:

- Emotional presentation

- Clear localization

Flaws:

- Simplification of timbres

The Italian speaker is made in the most classic design with veneer finishing. Before sawing out the walls of the body, HDF slabs are finished on both sides with natural wood. This makes the speaker more durable. The assembly and further processing of the case is carried out manually by specialists in Italy. Finished specimens are carefully tested to ensure compliance with the required acoustic parameters. The Silversoft Neodium model's tweeter uses a special membrane coated with aluminum powder, just like in the company's top-line speakers. It is interesting that a significant part of the mid-range is also devoted to the tweeter - starting from 1 kHz. The shape of the midrange/bass speaker diffuser, double curved, was selected by the designers specifically taking into account psychoacoustics and over the course of months of research.

Bookshelf speakers Chario Syntar 516

The bass reflex port ends in a simple hole cut asymmetrically into the bottom. High rubber feet on the bottom of the case allow the port to work quite efficiently.

Sound
The sound of the speakers is, on the one hand, soft and unhurried, and on the other, a very clear, active upper register. The timbre picture is slightly blurred, the smallest details are veiled. And yet the speakers manage to quite accurately and emotionally convey the mood of musical compositions. The bass is quite deep and slightly dominant in the overall sound picture. With good localization, the music scene lacks clarity and transparency. This is more noticeable on complex compositions. At low volumes the bass weakens, but the sound remains quite dynamic and emotional.

Measurements

The best frequency response is observed at a listening angle of 30°. The unevenness is relatively good, with an even roll-off in the low frequencies. SOI is quite good down to the lowest frequencies. The impedance is relatively stable.

Dynaudio DM 2/7

Sound: 5

Construction: 5

Price: 5

Advantages:

- Timbral fidelity

- Clean uppercase

Flaws:

- Strictness in presentation

The DM line is the entry-level acoustics in terms of the famous Danish company Dynaudio. The column is designed in a completely recognizable style of this company. The gray front panel is specially made thicker to effectively dampen chassis resonances. The body itself is also carefully sealed and finished with high quality traditional veneer. The branded tweeter is equipped with a 28 mm dome made of textile impregnated with a special compound. The diffuser of the midrange/woofer speaker is stamped from the already well-proven magnesium silicate polymer. The driver voice coils are wound on a Kapton base with lightweight aluminum wire. Together with powerful magnetic systems, this allows for remarkable dynamics and sensitivity.

Bookshelf speakers Dynaudio DM 2/7

Particular attention is paid to maximum impedance linearity to minimize speaker dependence on the amplifier.

Sound
The presentation of musical material by the speaker is relaxed and natural. Excellent tonal resolution makes the sound stage very believable. The spatial placement of instruments is clearly visible.

The bass is tight and well-developed. The upper register is clear and pleasant to the ear. The sound is highly detailed and lacks coloration. At low volumes the speakers play just as confidently as at high volumes.

Measurements

The frequency response is elongated into a very even strip with a barely noticeable skew towards high frequencies. The focus is broad. THD is low and stable. The impedance is quite stable. Exemplary results.

Magnat Quantum 753

Sound: 5

Construction: 4

Price: 4

Advantages:

- Timbral accuracy

- Clean music scene

Flaws:

- Slightly sparse sound

The speaker from Magnat's mid-priced Quantum 750 line looks solid. The front wall is made thick (40 mm) to radically combat body resonances. A solid 30 mm thick podium also emphasizes the solidity of the structure. It is curious that the front panel and podium are polished to a shine, while the rest of the surface of the case is matte. The F-max tweeter is equipped with a dome made of a double textile compound and has an extended operating frequency range. The midrange/bass speaker diffuser is made of ceramic/aluminum. The voice coil is well ventilated. The aluminum speaker basket design is optimized for optimal airflow and reduced resonances.

Bookshelf speakers Magnat Quantum 753

The bass reflex port with a large horn is located on the rear wall. The crossover is optimized for signal phase and amplitude and is assembled from selected high-quality elements.

Sound
The speakers play emotionally, dynamically, quickly. At the same time, the timbres of instruments are perfectly conveyed, and the musical scene is not obscured by extraneous sounds - they are pure and deep. Sound source localization is excellent. The detailing is also at a high level.

The HF level is enough for an open sound with the presence of airiness, and at the same time the upper register is very neat and unobtrusive.

Bass of medium depth, collected and fast. There is a little lack of physicality and density of presentation. At low volumes, the enthusiasm of the speakers is lost, the emotionality fades.

Measurements

The unevenness of the frequency response is minimal, but the frequency imbalance towards the HF is obvious. The SOI varies within 1% and noticeably depends on the volume, but no obvious resonances are noted. Good SOI margin at low frequencies. Impedance is unstable.

Martin Logan Motion 15

Sound: 4

Construction: 4

Price: 3

Advantages:

- Energetic delivery

- Fast and tight bass

Flaws:

- Weak at low volumes

The speakers are eye-catching with their stunning natural finish and attractive black steel grille. The housing cover is slightly tilted back. There is another surprise under the grille - a ribbon tweeter (a sign of an expensive device). The front panel of the speaker is made of black anodized aluminum. The diffuser of the long-throw midrange/woofer speaker is also made of black anodized aluminum to match the panel. The emitters are matched through a crossover with an improved topology, assembled using polypropylene capacitors and low-loss electrolytes, as well as hand-wound inductors.

Bookshelf speakers Martin Logan Motion 15

The circuit provides thermal and current protection. The bass reflex port is located on the rear wall. The speaker body is assembled from 19 mm thick MDF boards.

Sound
The peculiarity of the speakers is that they do not like to play at low and medium volumes. In this mode of operation, only the midrange remains of the frequency range, and the dynamics become inexpressive.

As the volume increases, fast, elastic bass and fairly detailed highs appear. However, the lower middle still continues to prevail. The presentation of the musical material is scathing. At the same time, we must pay tribute, no extraneous overtones are felt; on the contrary, after-sounds sometimes disappear even where they should be.

The model tends to simplify the instrument timbres a little. At the same time, the ribbon tweeter is very audible, which gives a characteristic delicate color to the mid-high range.

Measurements

Uneven frequency response in the HF region is noticeable. The decrease in sensitivity towards the low frequencies is quite sharp. The focus is broad. The SOI has slight rises in the midrange, but nevertheless remains below 1%. The impedance is relatively stable.

MK Sound LCR 750

Sound: 5

Construction: 5

Price: 4

Advantages:

- Focused sound

- Good tonal resolution

Flaws:

- Do not hide the shortcomings of the recording

All acoustic systems of the American company M&K Sound are made in black without any embellishment. And the main decoration of the products is compliance with the highest standards of sound reproduction. Series 750 is a compact set of speakers for creating a home theater. And the largest speaker in the series (not counting the subwoofer) is the 750 LCR model. The speaker is quite unusual, especially in our test. Firstly, the closed acoustic design reduces bass response. Secondly, the use of two midrange/woofer speakers at once significantly expands the dynamic range of the speaker. Third, the tweeter panel being rotated 4.7° away from the listener likely increases and/or equalizes the dispersion of various frequencies. The tweeter dome is made of silk coated with polymer.

Bookshelf speakers MK Sound LCR 750

The speaker diffusers are polypropylene, with mineral filler. Of particular note is the Phase-Focused crossover, which significantly improves almost all speaker parameters. The back wall has many threaded holes for different speaker mounting options.

Sound
Excellent control of musical material. The sound is almost monitor-like, smooth. All instruments are clearly visible: they are clearly defined both spatially and timbre. Nothing unnecessary interferes with the overall musical picture; all the nuances are heard clearly. And since there is no emotional coloring, the sound of the speakers is not as exciting as many other models, and depends entirely on the musical composition itself.

Measurements

Irregularities in the frequency response of the column are insignificant. A rotation of 30° gives the best results. The THD is very low and increases very smoothly towards low frequencies, exceeding 5% only at low volumes. The impedance is quite stable. Very worthy results.

PSB Imagine B

Sound: 5

Construction: 5

Price: 3

Advantages:

- Natural transmission of timbres

- Smooth dynamics

Flaws:

- HF area limited

The Canadian company PSB has been offering the Imagine line for several years. During this time, she managed to earn the Red Dot award for design and weight positive feedback various experts. The column body is a geometric intersection of several elliptical cylinders. All walls are curved. And this creates a feeling of solidity and strength of the structure. The 25 mm tweeter also looks solid - a dome made of durable titanium, the coil is cooled by magnetic fluid, and a powerful neodymium magnet. The midrange/bass speaker diffuser is made of polypropylene with clay-ceramic filler (mineral). The bass reflex port is located on the rear side. The column is finished with high quality natural veneer.

Bookshelf speakers PSB Imagine B

Sound
The sound is collected and well balanced in frequency. Excellent localization and natural transmission of timbres make the musical scene almost real, alive. Smooth dynamics allow the speakers to play naturally and freely even at low volumes. Musical matter is pure. The high-frequency range is slightly limited, due to which the airiness is partially lost, turning into intimacy.

Speakers can miss the smallest details, but at the same time maintain expressiveness and richness of sound. The bass, although not deep, is very well designed. The mid frequencies are also quite good, timbre rich and quite correct.

Measurements

A very flat frequency response measured along the acoustic axis. Turning the speakers away from the listener is undesirable - they begin to lose treble frequencies. SOI is stable and low down to the lower frequency limit. Impedance is stable.

Rega RS1

Sound: 5

Construction: 4

Price: 4

Advantages:

- Clean uppercase

- Wide dynamic range

Flaws:

- Slight coloration of sound

The English company Rega has developed and offers customers the only series of RS speakers. The purpose of their creation is to harmoniously complement other sound equipment also developed within the walls of Rega. However, speakers are available to buyers separately from this equipment. The RS1 model is quite compact and, judging by its weight, is assembled from thin MDF. Despite this, the performance of the speakers is top notch, with neat veneer finishing and a strict design. The drivers are designed by Rega engineers and hand-assembled in-house. The 19mm tweeter features a specially shaped rear chamber to better dampen sound waves from the back of the tweeter dome. Mid/bass speaker with paper diffuser.

Bookshelf speakers Rega RS1

The smooth frequency response of the speaker makes it easy to integrate it with a tweeter using a simple crossover with good phase locking. The bass reflex port is located on the rear wall.

Sound
The speakers reproduce timbres quite accurately, but due to the slight coloration, the music scene becomes a little less transparent. The upper register is missing quite a bit, but it is very clean. The details are present, but slightly veiled. Musical material is presented in a sweeping, open manner

The bass is quite accurate, but sometimes lacks weight. The localization of sound sources is somewhat blurred.

The speaker handles complex music somewhat worse - the intelligibility of the sound material decreases. However, at low volumes the speakers play very convincingly.

Measurements

Irregularities in the frequency response in the upper middle and high frequencies form the special character of the sound of the speakers. The speakers play more smoothly if they are rotated 30°. The SOI is unstable, but quite low, less than 1%. The impedance is extremely unstable.

Triangle Color Bookshelf

Sound: 5

Construction: 4

Price: 5

Advantages:

- Open live sound

- Accurate reproduction of timbres

Flaws:

- Slight excess bass

Very nice-looking speakers from the French manufacturer Triangle are available in three varnish colors - white, black and red. The Color line stands out with its bright, cheerful style among all Triangle products and takes its place as the entry-level line.

The bookshelf model uses a tweeter with a titanium membrane and a midrange/woofer with a paper cone. In general, the speaker is quite interesting; its suspension is wide, corrugated and basically made of fabric. The paper diffuser is coated with a special compound. The dust cap is designed in the shape of a bullet. The design of the crossover uses developments from the top Magellan line. The bass reflex port is located on the rear wall of the speaker.

Bookshelf acoustics Triangle Color Bookshelf

Sound
The sound of the model is very lively and natural. Timbre fidelity is very high. The presentation of sound material is natural and relaxed.

The dynamics amazingly accurately replicate a live performance. The bass is deep and beautifully defined. Sometimes it even seems like there is too much of it.

The musical matter is very pure and extremely detailed. No nuances escape the speakers' field of view.

They cope with compositions of any complexity. The sound quality is not lost even at low volumes.

Measurements

The imbalance of the frequency response towards the HF is obvious. It is treated as usual - turning the AC by 30°. The SOI is quite low, although in the midrange it is noticeably higher, but remains within 1%. High volume causes slightly more distortion in the upper bass. Impedance is unstable.

Wharfedale Jade 3

Sound: 5

Construction: 5

Price: 4

Advantages:

- Good detail

- Clear localization

Flaws:

- Slightly weakened dynamics

The British company Wharfedale traditionally spares neither effort nor materials even on budget lines. And the Jade 3 model once again confirms this. In our test, this is the largest and heaviest shelf speaker, and the only 3-way one. A body with curved walls is a feature of the top lines of many other manufacturers, but not Wharfedale. Both the body shape and the additional bulkheads make the body as acoustically inert as possible, preventing unwanted sound coloration. High frequencies takes over the aluminum dome tweeter. At the border of 3 kHz it is replaced by a midrange speaker with a diffuser made of aluminum-cellulose composite. And already in the region of 350 Hz, the initiative is seized by the woofer, equipped with a woven diffuser made of a mixture of carbon and fiberglass. The combination of such materials with a braided structure brings the diffuser closer to an ideal piston, eliminating the problematic resonance phenomena inherent in metal diffusers.

Bookshelf speakers Wharfedale Jade 3

The speakers operate in a closed volume. The crossover for the speaker was optimized on a computer for maximum linearity of signal phase transmission.

Sound
Wharfedale speakers sound traditionally beautiful. All instruments are clearly arranged spatially. The music stage is clean and spacious.

The speakers deliver bass carefully, not forcefully, as if they are afraid of damaging the balance of the overall sound picture. The same can be said about upper case.

The softness of the presentation of musical material is interestingly and harmoniously combined with excellent sound detail. In addition, the speakers play very well at low volumes.

Measurements

The frequency response of the model is flat, but at high frequencies it behaves peculiarly - a decline and a sharp rise. The bass is deep. The SOI is almost perfectly flat and extremely low. Very solid headroom for low frequencies. The impedance is quite stable.

conclusions

It should be noted that it is becoming less and less interesting to study the results of speaker measurements in our test laboratory. Almost all models showed a remarkably flat frequency response and a very low THD even in the bass region! This is explained by the fact that almost all companies have already adopted computer modeling tools, with the help of which you can make, perhaps, anything sound, which, for example, the company Boston Acoustics has proven to us more than once. Even the shape of the body no longer plays such a significant role; the main thing is to correctly calculate the damping elements. Therefore, the design ratings for all models are either good or excellent.

Two models from our test deserve special mention. These are MK Sound LCR 750 and Dynaudio DM 2/7. The companies that created them were initially focused on developing professional acoustics and pursue this line even in their youngest lines. The main principle is maximum accuracy in transmitting musical material. And no decorations. These two models fully meet this principle and, in fact, represent professional-level monitor acoustics, with all its advantages and disadvantages. Not all listeners may like the sound, or more precisely, the neutrality of the sound. This is a product for special music connoisseurs and connoisseurs, or even for a home studio. Both models are worthy of the sympathy prize.

Almost all companies have already adopted computer modeling tools, with the help of which you can make, perhaps, anything sound.

If we talk about beautiful and comfortable sound, then many of the speakers in our test successfully coped with this task. Accurate transmission of timbres, precise localization, accurate bass - all this is inherent in almost all speakers tested. The only difference is in the nature of the sound. And here the choice turned out to be rich: in the test you can find a dense, rich sound (PSB Imagine B), and an impressively sophisticated sound (Wharfedale Jade 3), and a collected, neat presentation of material (Canton Chrono 503.2), and an open airy image (Rega RS1, B&W 685), and even defiantly aggressive pressure (Martin Logan Motion 15). However, most of all I would like to highlight the French columns Triangle Color Bookshelf. They turn almost any musical material into a celebration of sound. The speakers know how to not miss the main idea of ​​the work and at the same time present the material very beautifully, lively and dynamically. They are very pleasant and interesting to listen to. The Triangle Color Bookshelf model takes the title of test winner.

1. The issue of acoustic resistance has already been discussed many times, but still I decided to return to it, due to the lack of a single final opinion on this matter! So, most modern amplifiers (based on their description) are usually designed to work with acoustics with a resistance of 6 - 8 Ohms. (8 Ohms seems to be the standard). At the same time, a lot of acoustics (especially those from the 70s-90s) have a nominal value of 4 Ohms! It is clear that this is precisely the “nominal” value, and that, in fact, this is a dynamic value, but still...! It is “stupidly” clear from physics that as the load resistance decreases, the current increases proportionally and there is a risk of burning the amplifier. With all this, some manufacturers openly declare the ability of their amplifiers to work with acoustics with almost any impedance, and some, on the contrary, warn against using speakers with inappropriate impedance! There are a lot of devices where these conditions are not specified at all! And what to do in this case, and in general, what is the general trend in this regard?
   I would like to understand once and for all:
   1-Is it possible to safely connect low-impedance speakers to any amplifier (both a transistor and a lamp)?
   2-it is absolutely forbidden (and compliance must always be strictly observed)?
   3-or is it a “lottery”, and everyone isolated case- is this a separate risk (or lack thereof)?
   Let's discuss!

2. Everything here, in principle, is quite banal and simple - when selecting an amplifier for speakers, be guided primarily by Class One, and not by performance characteristics. Let me explain.
   If you look at the circuit diagram of a budget and an expensive amplifier, then in principle there is no difference - complete parity... So what's the catch?
   In details and “safety margin” - budget amplifiers are designed for average volume with the possibility of short-term peaks, therefore the power supply unit, especially the transformer, is actually less powerful than the sum of two channels + efficiency. Output transistors and radiators, respectively, are also designed for this operating mode. Any transistors, especially bipolar ones, have an innate weak point - the crystal area. This crystal is physically unable to quickly transfer heat to the radiator and under long-term heavy load it simply melts - breakdown!
   In an expensive amplifier, everything is done with reserve - long-term maximum output power of both channels + efficiency + 25%. Also output transistors, radiators, wires, transformers, electrolytes... in short - EVERYTHING!
   All amplifiers, I repeat - ALL modern amplifiers(lamp and stone) are designed for ANY load. Another question is what is the sensitivity of the speakers and what is the class of the amplifier in a given room volume. The speaker resistance can drop to 3 ohms, but the sensitivity is 93dB - the current is not very high even for a budget amplifier. But if it’s 85dB, for the same speaker you need either a 4 times more powerful budget amplifier, or with the same power (initial for 93dB), but of a higher class (sound quality at this moment we do not consider).
   Here's the arithmetic...

3. Well, actually, the conclusion is again unfortunately ambiguous! Like - in theory, everything is possible, but in practice, who knows! Just relying only on the price and level of the manufacturer was a bit scary for me personally! For example, let's say, not very expensive NAD, nevertheless, boldly indicates in the manuals for its amplifiers various power values ​​​​with resistances from 8 to 2 ohms, thereby confirming the possibility of their devices operating with such a load. At the same time, for example, in the description of my Alchemist, which is clearly more expensive and higher level, there is only mention of an 8 Ohm load!
   I would like to clarify one more point - the connection of sensitivity to this whole story is not entirely clear.
   Since sensitivity is, say, not quite an “electrical” parameter, reflecting the degree of sound pressure created by a speaker at a certain distance, when 1 Watt of power is supplied, then what does the current have to do with it?
   In my understanding, when this one Watt is applied to acoustics with different sensitivity, but the same impedance, only the sound pressure created by it will change, in other words, one will simply play quieter. Why do we talk about increasing current?
   Another question about the lamp. There is often just a set of output connectors for different load resistances. I would like to understand the principles of this approach.

4. sensitivity, let’s say not quite an “electrical” parameter
   Sensitivity is the efficiency of acoustics. The lower the efficiency, the more current is needed to create the same sound. pressure.
   question about the lamp. There is often just a set of output connectors for different load resistances
   The 4-8-16 Ohm outputs are essentially the equivalent of an autotransformer. The bottom line is that the lowest distortion and highest efficiency in the transmission line (electrical term) is when the output impedance of the amplifier and the input speaker are matched. Tube amplifiers have a significantly higher output impedance, which is why they have a sectioned output winding of the transformer.
   By the way, some companies make one universal 6 Ohm output. But as practice shows, this is still a compromise and such amplifiers play better with a high-impedance load...
   in the description for my Alchemist, which is clearly more expensive and of a higher level, there is only mention of an 8 Ohm load!
   Yes, there are a lot of such companies - they indicate the optimal honest power. The load in reality is ALWAYS reactive and frequency-dependent, therefore the performance characteristics of NAD are deceit. They take an active resistor and measure it... this is for lovers of beautiful numbers and pictures.
   

5. Thanks for the clarifications!
   About sensitivity, it means we were talking about the same thing, but from different sides!
   Everything is clear now with the tube output too.
   Otherwise, it turns out that any experiments with connecting low-impedance acoustics are done at your own peril and risk!
   It’s not clear then, since so many predominantly vintage acoustics have an impedance of 4 Ohms, were the amplifiers of that time originally designed for this? (I'm just not very familiar with these types of amplifiers)

6. so many mostly vintage acoustics have an impedance of 4 ohms, were the amplifiers of that time originally designed for this?
   Certainly. It is not the low-impedance as such that is critical, but the sensitivity... Therefore, the amplifier is always selected according to the sensitivity of the speakers, the room and the genres, and everything else is for the gourmand of electronics engineers...

7. And what is the exact principle of selection? (and rather the opposite, if we select acoustics for an existing system) We simply proceed from the fact that the higher the sensitivity, the lower the risk of burning out? Or is it possible to approach the issue with some kind of calculations?

8. And what is the exact principle of selection? (And rather the other way around, if we select acoustics for an existing system) Simply We proceed from the fact that the higher the sensitivity, the lower the risk of burning? Or is it possible to approach the issue with some kind of calculations?

   Click to expand...

   Well, yes... But, first of all, we decide on the class of the amplifier and speakers - this is more important than all other parameters. And so -
   
   

9. Soooo, the further into the forest, the more questions!
   
   I can’t seem to get my head around the table! :-(Let's say you are interested in a volume level of about 80dB (at a distance of 1m as I understand it), let's say an acoustic system with a sensitivity of 91-95db. From the table we get something on the order of 0.6 watts???

10. I also want to add a nuance about our hearing. We hear the volume increase in a logarithmic sequence. If you notice, in magazines when measuring distortion and power, the scale is uneven 0.1-1-10-100... So, the difference in hearing between 10 and 100 watts is only two times... This is by the way about what is better In total, a person hears in the range of 0.1-10 watts (and why this range is very popular in tube technology), and then loses sensitivity to volume...
    
    

11. Soooo, the further into the forest, the more questions!
    What should be understood by the class of amplifier and acoustics?
    I can’t seem to get my head around the table! :-(Let's say you are interested in a volume level of about 80dB (at a distance of 1m as I understand it), let's say an acoustic system with a sensitivity of 91-95db. From the table we get something on the order of 0.6 watts???

    Click to expand...

12. Hmmm! Well then, can you (for me, an idiot) give an example of how to draw a conclusion from all this about which amplifier to choose!? And how to tie all this to the question of 4 Ohm acoustics.

13. To begin with - what kind of speaker? room... genres...

14. Well, as I already said, the question is rather about selecting acoustics for an existing amplifier. I’ll try to describe what I’m generally thinking about. There is a tube single-ended circuit, and Lately I came up with the idea of ​​assembling a separate tract based on it, because Although he plays soulfully with my Tannoy 638, he still does not control this acoustics as the transistor Alchemist does. Single-cycle craftsman, initially designed for 8 Ohm acoustics, approximate design power 5-6 W, one single pair of acoustic connectors. Accordingly, I decided to match the lamp with sensitive (most likely vintage) acoustics. Because There is simply no separate room for this tract; I am planning a somewhat strange option. This set should be located at my workplace (on the table near the computer) and will be listened to in close proximity to the acoustics. (although all this will still be located in a room with an area of ​​about 40 square meters!) Thus, the acoustics are planned to be bookshelf and not too large.
    Having started to study the offers on the secondary market, I was faced with the fact that a lot of such acoustics have a resistance of 4 or 6 Ohms! Well, that’s where the thoughts actually began...

15. Oh yes, genres... Well, here almost everything can be except heavy metal, although mostly jazz, jazz-rock...