Premium floor-standing acoustics: five leaders. Review of floor-standing acoustic systems: Stand your ground New budget floor-standing acoustics tests
Floor-standing acoustics are a system that has significant dimensions (especially vertically) and is installed directly on the floor, without the use of any additional devices. The main distinguishing feature of such devices is their higher sensitivity compared to shelf analogues. However, a floor-standing home audio system will only work fully if it is provided with a powerful amplifier, otherwise you will just get large speakers.
Such devices can be equipped with two, three or more frequency bands, but not in all cases the number of speakers corresponds to the “cavity” indicator. Very often, manufacturers equip their systems with two “woofers”, then it is called 2.5-way.
Let's try to identify the most distinguished models by presenting to your attention a short review from famous brands.
Sonus Faber Amati Anniversario
We can safely say about this system: “Handmade in Italy.” Even a quick glance at this model will be enough to say that we are looking at extremely high-quality and good acoustics from a famous brand.
Resembling a spindle from above and resembling a lute in profile, this serious structure is assembled from twelve maple bars carefully adjusted to each other and held together with a patented adhesive with a vibration-absorbing composition. Active acoustics with a cross section of this kind eliminate the occurrence of standing waves, plus, they will provide the user with excellent damping of the “cabinet”.
The manufacturer offers its fans only two finishing options - black (graphite) and wood (violin). Like the great creators of impeccable instruments Stradivarius and Guarneri, the brand hides the recipes of its varnishes, adhesives and subtleties of technology from prying eyes, emphasizing the fact that a home audio system is, in fact, the same means of playing music as a violin. That is why this model got its name in honor of the violin maker Andrea Amati from ancient Cremona.
Model characteristics
Sonus Faber is equipped with a double ring tweeter with a total diameter of 25 mm, without ferromagnetic fluid, but with an element optimizing the polar pattern. The sound efficiency corresponds to the “open acoustic chamber” design, that is, the design of the 150 mm midrange driver was made using the principles of Kellogg and Faraday.
Equipped with two 220 mm woofers with aluminum-magnesium diffusers plus a coil with a significantly increased working stroke. Each head is unloaded onto its own bass reflex port and is located in the rear part of the structure. All phase-amplitude characteristics are balanced, and the input impedance value is optimized for crossover frequencies of 350 and 4000 Hz (optimal acoustics). Reviews about “Sonus Faber” are extremely positive, and they are left by both ordinary users and specialist music lovers, so we can recommend this modern creation to everyone.
T+A KS 300
The 300th model was made the flagship of the entire series. The system turned out to be quite compact and somewhere even elegant with dimensions of 95 cm (height) and 19 cm (width) - stylish, simple and high quality.
This floor-standing speaker embodies the concept of a general approach to sound signature and know-how in technological solutions. All components that were involved in the design of the model are a continuation of the original T+A series and, at the same time, unique developments by the brand’s engineers.
The body is made of extruded aluminum, which provides the entire structure with rigidity and unshakability, and thanks to the exquisite solutions of local designers, the acoustics, speakers, and the entire appearance are saturated with elegance and high cost.
The side walls of the housing are damped with a proprietary material that can absorb any sound, while suppressing vibration for the entire structure, and at the same time reducing resonant vibrations.
The low-frequency speakers are matched to millimeter precision according to their parameters to the total volume of the body. Due to the carbon fiber reinforcement of the diffusers, the output is ultra-deep and extremely accurate low-frequency sound, even despite the volume level.
Series characteristics
Mid frequencies easily cover the entire vocal range from 200 to 2000 Hz, turning the sound into a dynamic, natural and incredibly lively instrument of perception. The diffuser, made using the latest GreyCone technology, has special notches that free it from any resonances, and due to the flexible suspension, the operation of the moving system is completely controlled and has excellent sound visibility. Such a plan has not yet been invented, and the legendary ring high-frequency radiator from T+A can cover frequency ranges up to 40,000 Hz and even higher without any effort. The overall sound image looks dynamic, airy and fast, without any trace of harshness or harshness.
A carefully calculated crossover filter involves dividing frequencies into three bands. It uses only the highest quality components, and the characteristics are carefully optimized. The filter prevents loss of linearity of speaker movements and keeps the sound within the established range. As a result, even large and extremely powerful signals present no difficulties for a three-way system. The KS-300 is an excellent model and excellent acoustics. Reviews about the system are mostly positive; the only thing users complain about is the modest color scheme, but this, as they say, is not for everyone.
Vienna Acoustic Beethoven Baby Grand
This model from the famous Grand brand can also be called the company’s flagship. "Beethoven" is a reflection of the superiority of the entire line of Vienna acoustic systems, which allows you to enjoy excellent sound both in large concert venues and in the home.
The model turned out to be dynamic, open and extremely musical, because the device combines two 6-inch speakers with low frequency, one with medium frequency, and the whole thing is completed by a tweeter with a silk diffuser.
Model features
The sound from the speakers is transparent and natural, and the mids and highs are perfectly balanced. The whole picture is complemented by two bass loudspeakers, where the user enjoys amazing balance and uniformity of sound. “Beethoven” is truly high-quality, modern and simply beautiful acoustics. Reviews about the model are entirely positive, so it is extremely difficult to find any critical points or nuances. Some owners complain that the system’s legs are too sharp and scratch the parquet, but this can easily be solved with a small mat or the “put it in and leave it alone” principle.
Opera Seconda
The Marshall acoustics pleased us with the Opera model. Just like in previous lines, the “closed box” was used as the sound design for this series. The new model received some visual updates, but the design principle itself has not changed at all, and why change something that works great.
The good acoustics feature a 2.5-way design, and the mid-woofers were developed in collaboration with Scanspeak. The diffusers are covered with high-quality aluminum with the addition of mastic to further reduce resonances. The speakers are molded into the housing and have a reinforced design.
System characteristics
The high-frequency section is equipped with a silk diaphragm and an innovative cooling system, where the operating range of the emitter is increased to 30 kHz. It is also worth noting that the amplitude of movement of the working diaphragm is almost 1 mm (twice as much as competing analogues), allowing high-frequency emitters to reach a higher level.
The tweeter is practically insensitive to any vibrations that come from other speakers in the system. All this is due to the resonant frequency (860 Hz) and due to the thick front panel (30 mm). Second-level acoustic separation filters have excellent circuitry, which is made on two separate boards and is located at a considerable distance from each other. This is done in order to reduce the unpleasant effect of mutual induction of the coils, and in addition, it allows you to get rid of the microphone effect.
All design elements undergo careful selection and testing at all stages of production, so we can say with confidence that “Opera” transmits the musical signal extremely accurately and correctly builds sound stages (surround acoustics). Reviews about the model are entirely positive, so there’s simply nothing to complain about, maybe only the price, but all high-quality acoustic systems are susceptible to this “disease.”
Epos M 16i
"Epos" is a floor-standing 2.5-way acoustic system with a phase inversion type. The model looks equally good as a stereo system and as a home theater. The series received an improved tweeter with an aluminum dome (25 mm), ferrofluid cooling for the coil and an excellent ferrite magnet, which greatly improved sound transparency compared to its predecessors.
Speakers
A speaker with mid frequencies (140 mm), together with a polypropylene diffuser, is built into the structure next to the tweeter and separated from the low frequencies by a special section. The speakers operate in the optimal frequency range thanks to a first-order filter (one tweeter - one capacitor).
It is distinguished by the presence of a dust-proof matrix instead of a phase distributor, and the bass reflex port located on the rear of the structure has symmetrical tubes to reduce the turbulence of the sound flow. The design also provides for by-wiring, and all key terminals are located on an anodized aluminum frame.
Yamaha NS 777
The Yamaha NS series acoustic set is a three-way bass-reflex floorstanding speaker in a stylish and distinctive body. The model has a Waveguide horn design, which means the presence of woofers with reinforced PMD membranes and high-quality proprietary wiring from Monster Cable. This allows the system to reproduce the most complex digital audio signals and accompany movies with any music sources.
In addition to excellent technical characteristics, the Yamaha acoustics set has a specific and at the same time elegant design, which is recognized by millions of fans of the brand. The body is polished black with a light speaker insert, which is typical for the brand’s products.
The size of the mid-frequency speaker remained the same from previous lines (130 mm), the sensitivity (89 dB) and the frequency range limits changed - 30-35,000 Hz. The rated power of the system does not exceed 100/250 W with a resistance of 6 ohms. There is also a Bi-Wiring function and detailed filter settings. The model is perfect for both professional and amateur needs.
Floor-standing speakers in the budget segment of the market have a serious advantage over bookshelf speakers: they do not require the purchase of racks, and tall enclosures do not necessarily have impressive dimensions. It's also worth noting that many speakers of this type have a bigger, stronger and bolder sound - so choosing the right set is very important to the quality of your system.
Having triumphantly passed the first test, the Wharfedale Diamond 230 immediately took on the battle. Hot on their heels is the new Q Acoustics 3000 series: the exceptionally talented budget bookshelf speakers QA 3020 have already made the Diamond 220 a lot of fun.
Also in the running are the Cambridge Audio Aero 6 - the superstar of an award-winning multi-channel package - and the miniature floorstanding speakers from JBL's new Arena range. They are all determined to fight to the end; who will win?
Cambridge Audio Aero 6 $900
We're already familiar with Aero 6: it's the brightest star of Cambridge Audio's double award-winning Aero 5.1 multi-channel package. They often visited our test laboratories, but always in the company of their brothers. Now they are performing a solo program - and taking into account the serious price reduction, they look like an exceptionally good purchase.
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For this amount you will get a lot of interesting things. Of course, we are talking about BMR speakers, which are often found in the company's higher-end models. The BMR head emits in a wide frequency range (from 250 Hz to 22 kHz), which allows you to move the band section to an area of lower hearing sensitivity. The distortion inherent in the frequency response point is less noticeable there, increasing clarity and improving matching.
At first glance, the 4.6 cm BMR driver can be mistaken for a regular tweeter; underneath there are two 16.5-centimeter midrange/bass emitters. Regular rectangular cases look very nice thanks to the natural veneer finish (walnut or ebony). A small bass reflex port on the front panel, similar in size to a BMR speaker, adds symmetry to the speaker.
The front port allows you to install the speaker near a wall; however, they play best at some distance from it and with a slight turn inward. The height of 98 cm and the proportionally voluminous design create a solid impression. But if you have room for them, you won't regret it.
The Cambridge has a truly inspiring sound - rich in detail, sharply focused and full of enthusiasm. They are noticeably different from most equivalent competitors.
The song Hooked on a Feeling by Blue Swede delights with enthusiasm and energy, fully conveying the powerful rhythmic drive and inspiration of the catchy melody.
The catchy chorus “hooga chaka” emphasizes the scale, volume and openness of the music scene. By the way, it is one of the main advantages of the Aero 5.1 multi-channel kit.
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Aero 6 - straightforward and purposeful; They are more confident than assertive. Reliable control ensures sound clarity and stability; Balance and high precision allow these speakers to play in such a way that it is impossible to tear yourself away.
The $1,500 Q Acoustics 3050 are a little more refined, but the Aero 6's heartfelt sound is highly detailed and isn't shy about showing off its enviable dynamic power. The drumming in "Aggressive Expansion" from the soundtrack to "The Dark Knight" is presented increasingly intensely, each blow is powerful and strong.
These beauties are also inferior to the Q Acoustics in terms of bass mobility, but they cannot be accused of lacking power and energy. The BMR speaker does an excellent job: the high frequencies are clear, detailed and coherent. The voices of any vocalists, be it the angelic melodies of Eva Cassidy or the patter of Kanye West, sound lively and intelligible.
If your budget is limited to $900, we highly recommend the Aero 6 for review. For this price you won't find anything better.
Grade: 5
BEHIND: Strong sound; spacious music stage; rhythmic drive; work in any range; coherence; robust construction; stylish front panel
AGAINST: Dimensions
VERDICT: Aero 6 are great; you won't find anything better for this price
Figures and facts
- Sensitivity:90dB
- Resistance:8 ohm
- Maximum power:120W
- Dual cable connection:No
- Finish options:2
- Dimensions (H×W×D):98×24×34 cm
JBL Arena 170 $500
Until recently, JBL's most affordable floorstanding speakers occupied the middle positions in the Studio or ES Series lines. This is no longer the case. With the release of the new budget Arena line, which includes two floorstanding models, two pairs of bookshelf speakers, a center channel speaker and a subwoofer, a JBL multi-channel set can be assembled for about $1,000.
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The smaller floorstanders in this set, the Arena 170, are the first of the new line in our labs, and they are very good.
If you need floorstanding speakers for a small room, be sure to check them out: they are compact, sound great when placed close to the wall (their bass reflex port is at the back), and do not overload the space.
But owners of large rooms should not discount them, although JBL is not capable of creating the same powerful sound as the Q Acoustics 3050 or Wharfedale Diamond 230.
This is partly due to the bass - quite detailed and moving, but not the most powerful and energetic, which makes the sound overall less weighty. The mighty crescendos are not as swift and impressive as they should be.
Still, the sound of the Arena 170 captivated us. Crisp and clean, lively and flexible, it, distinguished by accuracy and rhythm, is perfect for music of a wide variety of genres - from Van Morrison's blues rock to Eminem's bile rap.
The galloping rhythm of Frankly, Mr. Sh ankly by The Smiths never fails to lift the mood, with a fast and direct approach that doesn't feel intrusive. Thanks to the development of the musical scene, Morrissey's voice sounds clear and open. The treble is a little lacking in sophistication - the ubiquitous cymbals seem a little harsh.
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Despite the lack of scope, the stage is quite spacious, and even the dense ensemble of strings in the chorus does not cause crowds.
You can get denser and better sound by installing the speakers closer to the back wall and attaching the supplied spikes to the rubber feet. The correct selection of the system is very important; An amplifier that's agile and rhythmic in nature—like the $900 Marantz PM6005—is perfect. You should avoid components with too bright and dry sound.
We love the Arena 170's quirky, modern design: only the side panels are covered in natural wood veneer, while grainy plastic trims the front and funky angled rear; Perhaps this was done to save money, but it looks stylish.
Half-height protective grids make the facade more neat. If you remove them, the front panel reveals a scattering of bolts and holes, as if the speakers served as targets in a shooting range.
Hidden under the mesh is an inch soft-dome tweeter housed in an unusual waveguide, carried over from the company’s top “professional” models. According to JBL, it widens the angular radiation pattern and increases HF detail (the latter can be argued). Below it is a more traditional 18cm composite mid/bass driver.
The Arena 170s don't have the versatility of the sub-$1000 category leaders, but they do have a very pleasant and engaging sound. If these are any indication of the entire line, we're looking forward to the rest of the models. Follow the news!
Grade: 4
BEHIND: Lively and flexible; clean and crisp sound; suitable for small and uncomfortable rooms; quality of finish
AGAINST: LF lacks energy and density; strong competitors in the category up to $1000
VERDICT: Not perfect at everything, but talented in many ways
Figures and facts
- Sensitivity:87dB
- Resistance:8 ohm
- Maximum power: 200W
- Dual cable connection:No
- Finish options:2
- Dimensions (H×W×D):96×22×28 cm
Q Acoustics 3050 $1150
Q Acoustics' 2000i series has won a ton of awards over the years, and its developers have worked hard to reach new heights. Meet the 3000 Series - the latest budget line.
That doesn't mean it's time to say goodbye to the 2000i Series - it will remain on shelves until the end of the year - but as word spreads, sales will slow down.
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We had a hunch that the floor-standing speakers 3050 should be good - their bookshelf counterparts received the epithets “sensation” and “phenomenal” in the review. And so it turned out: we are completely fascinated.
The changes made to the 2000i series more than justify its relaunch. The cones of a pair of 16.5-centimeter midrange/woofers are now made of paper and aramid (or Kevlar); According to Q Acoustics, this material enhances the natural sound character.
The inch tweeter is decoupled from the body using butyl rubber, which insulates it from vibrations. High-quality crossover components help reduce distortion and phase failure at the crossover point.
The case with walls made of MDF 1.5 cm thick is closed on top with a two-centimeter double-layer panel, and on the front with an even thicker one; Stiffening ribs increase strength and suppress resonances. Terminals for two-cable connection are now on the rear panel, rather than on the bottom; it's much more convenient.
The manufacturing quality of heavy-duty cases is traditionally high. Rounded ribs are already familiar; high-end trim - one of two standard (matte graphite and black American walnut) and three optional (black or white lacquer or black leather) options, for $1,500 each. Externally, they resemble the 2050i model, but are slightly narrower (30 cm) and flatter (20 cm). The plinth and adjustable cleats are carried over from the older Concept 40; Thanks to them, the speakers are able to stand stably on any surface.
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However, the reduction in size did not affect the sound quality: the 3050 is good in all respects. Carefully recreating Q Acoustics' signature sophisticated approach, they are even more compelling, transparent and precise than their predecessors.
Full-bodied, mobile and mellifluous bass, as well as clear, controlled highs determine their tonal character - a little richer than neutral, as always with Q Acoustics. Their sound is full, dense and strong throughout the entire frequency range.
You will never guess by the sound that the volume of the case has been reduced. Powerful and assertive, the speakers are impressive in scale and can easily fill even the largest of our test labs. Even if you place them very far from each other, this will not reduce the density of the stereo panorama; The best sound quality is achieved when positioned approximately 20 cm from the wall.
Their measured musicality and precise rhythmic drive create amazing sound magic; we listened to the entire Dire Straits album without even realizing it.
By the time the song Brothers in Arms began, we did not feel the slightest sign of fatigue from the speakers. The electric guitar solo is free-flying, the soft vocals are full of emotions.
The Q Acoustics 3050 is another remarkable achievement from the company; they are capable of giving a decent fight to speakers with a price approaching $2000. They are simply great.
Grade: 5
BEHIND: Richness and elaboration; maximum sophistication; power and persuasiveness; rhythmic drive; construction and finishing
AGAINST: Nothing
VERDICT: Q Acoustics has raised the bar even higher, setting a new price point standard
Figures and facts
- Sensitivity:92dB
- Resistance: 6 ohm
- Maximum power: 100W
- Dual cable connection: Yes
- Finish options:5
- Dimensions (H×W×D):100×30×20 cm
Wharfedale Diamond 230 $650
It's amazing how much can change in the blink of an eye. Take Wharfedale's new floorstanding speakers, for example: they received a perfect rating just a month ago, but have already fallen short compared to capable rivals. But this does not mean that Diamonds 230 has become worse; If you're looking for talented floorstanding speakers with compact dimensions but big sound, these are worth a look.
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The immersive sound of the Diamond 230 - 95 cm high and 32 cm deep - makes these robust speakers feel even larger. The chorus of Macklemore and Ryan Lewis' "Wing$" fills the music stage with a dramatic crescendo that few competitors can match.
However, their powerful image does not reduce mobility: Diamond 230 is characterized by enviable energy and drive. The neutral tonal character is convincing, the bass is deep and powerful, and the treble is clear and precise.
The crossover has been redesigned to improve coherence between speakers; In our opinion, the goal has been achieved - the midrange is presented exceptionally harmoniously.
The Q Acoustics 3050's timing and note placement are a little more precise, but the Wharfedale approach is very pleasing, with a natural warmth and softness to the instruments. But one cannot blame them for their smoothness and toothlessness: every sound turns out to be dense and strong.
The piano in Rachmaninov's Rhapsody on a Theme of Paganini plays with weight and speed, the changing intensity of each stroke demonstrating the excellent dynamics of the Diamond 230.
But in this regard, Q Acoustics is stronger: they have higher texture of the keys, the listener receives more timbral information.
Wharfedales work best when there is free space - at least 30cm from the back wall and 60cm from the sides. A slight turn towards the listener increases the density of the stereo panorama, but reduces the width of the music stage.
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The unusual acoustic design, first used in the Diamond 100 series, increases the versatility of the installation. Instead of using the more conventional rear or front bass reflex port, Wharfedale decided to direct the air down into the gap between the cabinet and the speaker base. Thanks to this, they are not as capricious in location as many competitors; In addition, the noise level is reduced.
Luckily, the Diamond 230 doesn't inherit the finish of the 100 series, which was the subject of many complaints about its uneven quality. The new building does not cause any complaints; Carefully bonded vinyl trim and neat ribs rival those found in the competition. The lacquered front panel looks very stylish.
In addition to the new housing and improved crossover, it is worth noting the enlarged magnet of the woofer, which enhances its responsiveness and facilitates “pumping”. Twitter remains the same; it is surrounded by a deep waveguide, increasing its efficiency.
The loss of valuation would be a sad surprise for Wharfedale. However, these speakers are still very good; Thanks to their versatility, they can be used in a variety of rooms and systems.
Grade: 4
BEHIND: Surround and large-scale sound; spacious music stage; neutral tonal character; accuracy and density; construction and finishing
AGAINST: Lacks texture and finesse
VERDICT: Having lost their high ratings, Wharfedale speakers still deserve attention
Figures and facts
- Sensitivity:88dB
- Resistance:8 ohm
- Maximum power:150W
- Dual cable connection: Yes
- Finish options:4
- Dimensions (H×W×D):95×20×32 cm
Let's sum it up
Winner Q Acoustics 3050 $1150
Competition in the budget segment is extremely high, no matter what type of product we are talking about, and floor-standing speakers are no exception. With the Q Acoustic 3050 raising the bar in its category, you can now buy as great speakers as ever for under $1,500.
With improvements to the award-winning 2050i, the British company has once again set higher standards for floor-standing speakers. The unrivaled refinement and musicality of the Q Acoustic 3050 allows them to outshine the competition.
We feel sorry for the Wharfedale 230, which has lost its top rating after just a month. But they are still very good: power, precision, enthusiasm and excellent finishing are very pleasing.
We wouldn't hesitate to put them on our list of recommendations, but there are better options out there today in terms of value for money. Among them is the Cambridge Audio Aero 6, which has entered the five-star club thanks to a sharp price cut. Their energy, strength and meticulousness are much higher than you would expect from a $900 speaker.
We were pleased with JBL's return to the budget segment. The Arena 170 is another decent pair of speakers - especially good for small or awkward rooms. We look forward to the next models in the Arena line.
We are pleased to report that all four test pairs performed excellently. But if we were choosing speakers for ourselves, we would definitely go with the Q Acoustics 3050.
COMPLETE THE SYSTEM
Three partners to get the most out of the amazing Q Acoustics 3050
CD player
Marantz CD6005 $700
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Fantastic value for money; its predecessor was already a leader, and this model received our award in 2014
Amplifier
Marantz PM6005 $900
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An excellent amp and one of our favorites; affordable price and excellent sound quality of any analog and digital music
Network music player
Bluesound Node $700
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A 2014 award winner, this modestly priced player is a great addition to your system.
For any home audio system, the right choice of acoustics is one of the main points. After all, it’s hard to imagine another component that would be able to have such a serious impact on the sound quality. One model will delight even when working with the simplest music center, while the other is capable of “killing” the sound with the best models of High-End complexes. We bring to your attention a review of floor-standing acoustics that will be a win-win option.
Features of floor-standing speaker systems
Despite the higher cost and relatively large dimensions, equipment of this particular class is especially in demand among professionals. Its choice provides many advantages:
- high quality (especially in comparison with shelf models) of low frequency reproduction;
- greater dynamic range of audio frequencies;
- more powerful and deeper bass;
- There is no need to purchase additional stands to install speakers.
As the most successful examples in the review of floor-standing speakers, I would like to offer you several interesting options: PolkAudio Signature S60, B&W 804D3, Dynaudio Excite X38, Dynaudio Contour 30.
PolkAudio Signature S60
Signature Series Features
The Signature series is positioned by the manufacturer as an acoustic system that implements a new quality standard. To achieve this task we used:
- Dynamic Balance technology, which allows you to determine the most effective geometric shapes and the best materials that provide the most realistic sound quality;
- optimized speaker design due to the installation of a distortion analyzer, which uses the Klippel system;
- Power Port technology, patented by the manufacturer, to reduce noise and significantly increase sound pressure at the lower frequency limit, which ultimately makes it possible to use the amplifier power more efficiently and produce more concentrated, detailed and deep bass;
- polymer diffusers for mid- and low-frequency speakers using mica filler.
As part of a review of floor-standing acoustics, it is difficult to ignore one of the recognized leaders in its field and the senior model of the series. If you are planning to install a Hi-Fi home theater, this model is created just for you! Among the main advantages of the model are:
- two-way bass reflex acoustics with an inch tweeter with a Mylar dome, which is optimal for high-quality reproduction of High-Res audio;
- a lower limit of operating frequencies, which ensures greater uniformity of the sound field at mid-frequencies, which are critical for the listener;
- high sound purity due to the presence of an anti-resonance housing made of MDF;
- cascading crossover that provides realistic sound regardless of which zone of the room the listener is in.
The only significant “minus” is the ability to work only with AV receivers or low-power amplifiers due to the sensitivity of 90 dB.
B&W 804D3
Bowers and Wilkins (B&W) is one of the few manufacturers that can prove its ability to develop equipment for connoisseurs of impeccable realistic sound. The secret of success is the active development and implementation of the best existing acoustic technologies. - Hi-End level product.
Proprietary technologies as the secret to the model’s success
With each subsequent model, B&W manages to achieve benchmark quality. This is achieved thanks to the following factors:
- Diamond tweeters for rich tones and perfect sound purity.
- Low-frequency Aerofoil diffusers that provide volume and depth of sound, impressive bass.
- Matrix system with internal ribs of increased rigidity, providing additional reliability of the frame.
Advantages and disadvantages of the model
In addition to the advantages listed above, owners of the B&W 804D3 will be pleased with:
- Impeccable sound purity in any frequency range.
- Increased design reliability.
- Rigid, inert housing that eliminates vibration.
- Composite structure of the diffuser, providing greater openness of sound.
But at the same time you will have to come to terms with the impressive weight and the cost corresponding to all the listed advantages.
Dynaudio Excite X38
This model is the flagship in its series, during the development of which the manufacturer managed to achieve a denser and more realistic sound in comparison with previously released models. In addition, it is worth highlighting the possibility of selecting speakers with a power of up to 250 W and high sensitivity (up to 88 dB), thanks to which the sound quality will be ideal even at low volumes.
Features of the technologies used
A key feature of the brand was the technology of using magnesium silicate material patented by the manufacturing company for the manufacture of diffusers with a diameter of 18 cm. In addition, it is worth noting:
- new heads for low frequencies;
- voice coils with a diameter of 75 mm, which are wound using aluminum wire;
- cast basket of reinforced design;
- magnetic system made of neodymium alloy.
Advantages and disadvantages of the model
A review of floor standing column brands and models revealed that they are characterized by:
- delicate, clear, but still energetic “low”;
- coordinated work of a bunch of mid- and low-frequency heads;
- clear, rich sound at high frequencies;
- large frequency range (34 Hz - 24 kHz).
Such acoustics will satisfy the tastes of the most demanding listeners and will delight them with multi-dimensional, balanced sound.
Among the disadvantages of the model, we can only note the rather impressive cost in comparison with analogues of other brands. Although it is relative, if you take into account other characteristics.
Dynaudio Contour 30
As part of this line, the manufacturer offers a two-way floor-standing speaker system for medium-sized rooms. It will not come as a surprise to users who are already familiar with the equipment of this series in terms of transparency and sound authenticity. But there are also important features that are specific to the Contour 30.
Model features
- Bass reflex, equipped with two ports.
- Increased speaker travel.
- Different diffuser thicknesses.
- Aluminum coils to reduce the weight of the speakers and increase the length of the winding, which improves handling. This is especially important when playing sound at high volumes.
- New speaker mounts.
Advantages and disadvantages of the model
- Clearer bass thanks to the new crossover.
- Excellent load capacity.
- No speaker vibration during operation due to the use of a durable solid aluminum plate on the front panel.
- Reduced levels of resonances, vibrations, and increased structural rigidity are ensured by the multi-layer structure of the body, which is made by hand.
Contour 30 allows us to say with confidence that today it is one of the best models in its class. The only thing that somewhat limits its popularity is the high cost, which is typical for most of the brand’s products.
Knowing the features of the most popular bookshelf acoustics models, you can easily choose the ideal option for yourself! You can view the full product catalog on our online store website.
Achieving clear and spacious sound is not the easiest task, especially when it comes to budget segment acoustics. High-quality systems allow you to transmit sound with maximum detail and reproduce high, mid and low frequencies in a balanced manner. What types of acoustic speakers exist, and how to choose the right equipment for home use? An acoustic system is a device for sound reproduction, consisting of an amplifier, several emitters (most often dynamic) and electrical filters for dividing the reproduced frequency range between loudspeakers. The optimal spectrum for mid- and high-class speakers is considered to be a frequency from 20 Hz to 20 kHz. This allows you to produce a noticeable “springy” bass and crystal clear vocals. Of course, frequency range indicators cannot fully reflect sound quality. For this purpose there is an amplitude-frequency characteristic. There are two main types of speaker systems - active and passive. Active speakers, in addition to the crossover and speaker, contain a built-in power amplifier inside the housing. This makes them more versatile and compact than passive component systems. Active closed-type acoustics can include not only a sound source, but also a player, a pre-processing console, and even an entire instrument. This allows you to quickly configure and assemble the equipment. However, active systems are not suitable for large halls and clubs because they concentrate sound in one specific location. Passive acoustics require a separate amplifier, and in some cases a crossover. It will not be convenient for small halls or clubs, since it takes up quite a lot of space. But such equipment copes better with creating a sound atmosphere in large rooms. Another advantage is the even distribution of power, reducing the risk of amplifiers overheating. Based on their location in the apartment, acoustic systems are divided into shelf, floor, built-in and wall-mounted. They differ in size, sound transmission quality, ergonomics and service life. Let's discuss each type of accommodation in more detail. Such speakers are installed mainly in small rooms up to 18 square meters, but there are models that can fill even large concert halls with sound. Shelf systems are not nearly as compact as they seem at first glance. They can only be installed on special mounts. That is, saving space, as is the case with built-in or wall-mounted acoustics, will not work. If you try to install bookshelf speakers on a regular table or shelf, they will begin to resonate and vibrate strongly, which will certainly spoil the sound quality. Some people think that bookshelf speakers are great for home theater use. But it’s still better to use floor-standing equipment, as it gives richer bass and creates an immersive effect. At the same time, the quality of sound transmission depends not so much on the type of speaker, but on the quality of the speakers, components and room area. For small rooms it is better to use shelf units, for large rooms - floor units. Advantages: Flaws: Floor-standing speaker systems are most often used in halls and clubs with an area of more than 20 square meters. The richness of the sound in such systems directly depends on the chosen amplifier. As a rule, floor-standing devices are more demanding of load, so an incorrectly selected amplifier can damage the equipment. Before purchasing, be sure to compare the power ratings of the speakers with the power ratings of all components. If you over- or under-estimate your receiver, it may not deliver its full audio potential or may cut out when the volume is turned up. Advantages: Flaws: Built-in speaker systems are most often installed in ceilings or walls. Unlike shelf and wall-mounted devices, their housing is completely hidden and does not take up space. Usually only the speaker grilles remain visible, but there is special “invisible” equipment where even the radiator is covered with a thin layer of plaster. Such speakers are suitable for commercial premises such as clubs, supermarkets, sports centers, etc., as they are resistant to external factors. They are distinguished by less natural sound transmission, but good compactness. However, you will also have to pay a large sum for the process of installing acoustics. Advantages: Flaws: Hanging speakers are a budget-friendly and fairly compact alternative to shelf systems. They save space in the room because they have a small emitter and a lightweight body. Hanging systems are great for home theaters and TVs because they have sufficient sound performance for watching movies and other video files. However, the playback quality is not up to par with floor-standing or bookshelf acoustics, so music lovers are better off paying attention to more professional models. Advantages: Flaws: When choosing speakers for your home, you need to pay attention to technical characteristics, such as frequency range, number of bands, playback area, impedance level, maximum sensitivity and compactness. Here are some useful tips to help you choose acoustics for your home: Also pay attention to the dimensions of the device. You should not choose bulky speakers for small apartments, as they will take up a lot of space and will not provide the desired sound. Powerful acoustics in small rooms can hum or distort the sound. Buying a home audio system from a reliable manufacturer means getting a long warranty period, good service and constant customer support. If you are ready to spend enough money to buy a quality device, we present you a list of the best audio equipment manufacturers: Each of these brands creates excellent equipment for any occasion. The equipment lasts a long time and pleases with good sound quality. Manufacturers produce many models of acoustic speakers, but not all of them sound good. It is especially difficult to find a high-quality device among representatives of suspension systems. We have compiled a rating of the top 9 best acoustics of different types, based on reviews and customer feedback:Placement
Shelf
Floor-standing
Built-in
Hanging (wall-mounted)
How to choose for your home
Manufacturers
Rating 2019
Floor-standing
- need a subwoofer;
- require warming up.
The best acoustics from the Censors range. It has a durable aluminum base that protects the case from external damage. The side panels are made of MDF and covered with high quality laminate. The suspension design and patented wood-finished diffuser provide excellent sound transmission and long-lasting music listening.
- high-quality sound;
- suitable for home cinema;
- Excellent sound in both stereo and five-channel mode.
- low quality cladding;
- great weight and size.
Home acoustics that can provide excellent sound quality even in large rooms. The speaker cones are covered with a layer of craft paper. Thanks to a special ferromagnetic fluid, the system operates stably at high volumes and does not overheat. The device is suitable for both home and commercial use.
- high power;
- deep and springy bass;
- smooth amplitude-frequency response.
- you need an equally expensive amplifier.
Premium acoustics from the famous American manufacturer Polk Audio. Balanced six-layer laminate design with five liquid layers creates the best shear suppression system. The special rounded wall shape reduces resonance and reduces distortion.
Hanging
- affordable price;
- two playback bars;
- high sensitivity;
- quick installation.
- not enough bass.
Inexpensive 2-way wall-mount stereo system. It is positioned by the manufacturer as all-weather, since it has a protected housing and speakers. Equipped with high quality surge protection and a 90 by 90 degree HF horn.
- suitable for outdoor use;
- takes up little space in the apartment;
- high sound quality.
- you need a good amplifier.
All-weather speaker system from the GLE range - one of the most popular series in Europe. Equipped with an innovative frequency filter and bass resonant hole. Suitable for both connection with a home theater and for use in music classes, cafes, restaurants, sports clubs, etc.
We continue our tradition and publish another article in the “testing methods” series. Articles such as these serve as both a general theoretical framework to help readers gain an introduction to the topic, and specific guidance for interpreting test results obtained in our laboratory. Today's article on the methodology will be somewhat unusual - we decided to devote a significant part of it to the theory of sound and acoustic systems. Why is this necessary? The fact is that sound and acoustics are practically the most complex of all the topics covered by our resource. And, perhaps, the average reader is less savvy in this area than, say, in assessing the overclocking potential of various Core 2 Duo steppings. We hope that the reference materials that formed the basis of the article, as well as a direct description of the measurement and testing methodology, will help fill some gaps in the knowledge of all lovers of good sound. So, let's start with the basic terms and concepts that any novice audiophile must know.
Basic terms and concepts
A short introduction to music
Let's start in an original way: from the beginning. From what sounds through the speakers, and about other headphones. It just so happens that the average human ear can distinguish signals in the range from 20 to 20,000 Hz (or 20 kHz). This fairly substantial range, in turn, is usually divided into 10 octaves(can be divided by any other quantity, but 10 is accepted).
In general octave is a frequency range whose boundaries are calculated by doubling or halving the frequency. The lower limit of the next octave is obtained by doubling the lower limit of the previous octave. Anyone familiar with Boolean algebra will find this series strangely familiar. Powers of two with an added zero at the end in their pure form. Actually, why do you need knowledge of octaves? It is necessary in order to stop the confusion about what should be called lower, middle or some other bass and the like. The generally accepted set of octaves clearly determines who is who to the nearest hertz.
|
Octave number |
Lower limit, Hz |
Upper limit, Hz |
Name |
Title 2 |
|
Deep Bass |
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|
Mid Bass |
Subcontrol |
|||
|
Upper Bass |
||||
|
Lower middle |
||||
|
Actually the middle |
||||
|
Upper middle |
||||
|
Bottom top |
||||
|
Middle top |
||||
|
Upper high |
||||
|
Upper octave |
||||
The last line is not numbered. This is due to the fact that it is not included in the standard ten octaves. Pay attention to the column "Title 2". This contains the names of the octaves that are highlighted by musicians. These “strange” people have no concept of deep bass, but they have one octave above - from 20480 Hz. That is why there is such a discrepancy in numbering and names.
Now we can talk more specifically about the frequency range of speaker systems. We should start with some unpleasant news: there is no deep bass in multimedia acoustics. The vast majority of music lovers have simply never heard 20 Hz at a level of -3 dB. And now the news is pleasant and unexpected. There are no such frequencies in a real signal either (with some exceptions, of course). An exception is, for example, a recording from an IASCA Competition judge's disc. The song is called "The Viking". There, even 10 Hz are recorded with a decent amplitude. This track was recorded in a special room on a huge organ. The judges will decorate the system that wins over the Vikings with awards, like a Christmas tree with toys. But with a real signal everything is simpler: bass drum - from 40 Hz. Hefty Chinese drums also start from 40 Hz (among them, however, there is one megadrum. So it starts playing as early as 30 Hz). Live double bass is generally from 60 Hz. As you can see, 20 Hz is not mentioned here. Therefore, you don’t have to worry about the absence of such low components. They are not needed to listen to real music.
The figure shows a spectrogram. There are two curves on it: purple DIN and green (from old age) IEC. These curves display the spectrum distribution of the average musical signal. The IEC characteristic was used until the 60s of the 20th century. In those days, they preferred not to mock the squeaker. And after the 60s, experts noticed that listener preferences and music had changed somewhat. This is reflected in the great and mighty DIN standard. As you can see, there are much more high frequencies. But there was no increase in bass. Conclusion: no need to chase super-bass systems. Moreover, the desired 20 Hz was not put in the box there anyway.
Characteristics of acoustic systems
Now, knowing the alphabet of octaves and music, you can begin to understand the frequency response. Frequency response (amplitude-frequency response) - dependence of the oscillation amplitude at the device output on the frequency of the input harmonic signal. That is, the system is supplied with a signal at the input, the level of which is taken as 0 dB. From this signal, speakers with an amplification path do what they can. What they usually end up with is not a straight line at 0 dB, but a somewhat broken line. The most interesting thing, by the way, is that everyone (from audio enthusiasts to audio manufacturers) strives for a perfectly flat frequency response, but they are afraid to “strive.”
Actually, what is the benefit of the frequency response and why do the authors of TECHLABS constantly try to measure this curve? The fact is that it can be used to establish real frequency range boundaries, and not those whispered by the “evil marketing spirit” to the manufacturer. It is customary to indicate at what signal drop the boundary frequencies are still played. If not specified, it is assumed that the standard -3 dB was taken. This is where the catch lies. It is enough not to indicate at what drop the boundary values were taken, and you can absolutely honestly indicate at least 20 Hz - 20 kHz, although, indeed, these 20 Hz are achievable at a signal level that is very different from the prescribed -3.
Also, the benefit of the frequency response is expressed in the fact that from it, although approximately, you can understand what problems the selected system will have. Moreover, the system as a whole. The frequency response suffers from all elements of the path. To understand how the system will sound according to the schedule, you need to know the elements of psychoacoustics. In short, the situation is like this: a person speaks within medium frequencies. That’s why he perceives them best. And at the corresponding octaves the graph should be the most even, since distortions in this area put a lot of pressure on the ears. The presence of tall narrow peaks is also undesirable. The general rule here is that peaks are heard better than valleys, and a sharp peak is heard better than a flat one. We will dwell on this parameter in more detail when we consider the process of measuring it.
Phase frequency response (PFC) shows the change in the phase of the harmonic signal reproduced by the speaker depending on the frequency. Can be uniquely calculated from the frequency response using the Hilbert transform. The ideal phase response, which says that the system has no phase-frequency distortions, is a straight line passing through the origin of coordinates. Acoustics with such a phase response are called phase-linear. For a long time, no attention was paid to this characteristic, since there was an opinion that a person is not susceptible to phase-frequency distortions. Now they measure and indicate in the passports of expensive systems.
Cumulative Spectral Attenuation (CSF) - a set of axial frequency response (frequency response measured on the acoustic axis of the system), obtained with a certain time interval during the attenuation of a single pulse and reflected on one three-dimensional graph. Thus, from the GLC graph one can accurately say which regions of the spectrum will decay at what speed after the pulse, that is, the graph allows one to identify delayed resonances of the AS.
If the KZS has many resonances after the upper middle, then such acoustics will subjectively sound “dirty”, “with sand on the high frequencies”, etc.
AC impedance - this is the total electrical resistance of the speaker, including the resistance of the filter elements (complex value). This resistance contains not only active resistance, but also the reactance of capacitors and inductances. Since reactance depends on frequency, impedance is also entirely dependent on it.
If they talk about impedance as a numerical quantity, completely devoid of complexity, then they speak about its modulus.
The impedance plot is three-dimensional (amplitude-phase-frequency). Usually its projections on the amplitude-frequency and phase-frequency planes are considered. If you combine these two graphs, you get a Bode plot. And the amplitude-phase projection is a Nyquist plot.
Considering that impedance depends on frequency and is not constant, you can easily determine from it how difficult the acoustics are for an amplifier. Also, from the graph you can tell what kind of acoustics it is (ZYa - closed box), FI (with a bass reflex), how individual sections of the range will be reproduced.
Sensitivity - see Thiel-Small parameters.
Coherence - coordinated occurrence of several oscillatory or wave processes in time. This means that the signal from different GG acoustic systems will arrive at the listener simultaneously, that is, it indicates the safety of phase information.
Listening Room Meaning
The listening room (among audiophiles is often shortened to KdP), and its conditions are extremely important. Some put the CDP in first place in importance, and only after that - acoustics, amplifier, source. This is somewhat justified, since the room is capable of doing whatever it wants with the graphs and parameters measured by the microphone. Peaks or dips in the frequency response may appear that were not observed during measurements in a quiet room. Both the phase response (following the frequency response) and the transient characteristics will change. In order to understand where such changes come from, we need to introduce the concept of room modes.
Room mods are the beautifully named room resonances. The sound is emitted by the speaker system in all directions. Sound waves bounce off everything in the room. In general, the behavior of sound in a single listening room (CLR) is completely unpredictable. There are, of course, calculations that allow us to evaluate the influence of various modes on sound. But they exist for an empty room with an idealized finish. Therefore, it is not worth presenting them here; they have no practical value in everyday life.
However, you must know that resonances and the reasons for their appearance directly depend on the frequency of the signal. For example, low frequencies excite room modes, which are determined by the size of the CDP. Bass boominess (resonance at 35-100 Hz) is a clear representative of the appearance of resonances in response to a low-frequency signal in a standard room of 16-20 m 2. High frequencies give rise to slightly different problems: diffraction and interference of sound waves appear, which make the directivity characteristics of the speakers frequency-dependent. That is, the directionality of the speakers becomes increasingly narrow with increasing frequency. It follows from this that the listener will receive maximum comfort at the intersection of the acoustic axes of the speakers. And only him. All other points in space will receive less information or receive it distorted in one way or another.
The influence of the room on the speakers can be significantly reduced if the control panel is muffled. For this, various sound-absorbing materials are used - from thick curtains and carpets to special slabs and cunning configurations of walls and ceilings. The quieter the room, the more the speakers contribute to the sound, and not the reflections from your favorite computer desk and pot of geraniums.
Recipes for placing speakers in a room
Vandersteen recommends placing speakers along the long wall of the room at points where low-frequency modes are least likely to occur. You need to draw a plan of the room. On the plan, divide the long wall successively into three, five, seven and nine parts, draw the corresponding lines perpendicular to this wall. Do the same with the side wall. The intersection points of these lines will indicate those places where the excitation of low frequencies in the room is minimal.
Lack of bass, lack of tight and clear bass:
try moving the speakers closer to the back wall;
check whether the stands under the speakers are stable: if necessary, use spikes or conical legs;
Check how solid the wall behind the speaker is. If the wall is flimsy and makes noise, place the speaker in front of a strong (solid) wall.
The stereo image does not extend beyond the space limited by the speakers:
move the speakers closer to each other.
There is no depth of sound space. There is no clear sound image in the center between the speakers:
select the optimal height for the speakers (use stands) and your listening position.
Sharp annoying sound in the mid and high frequencies:
if the speakers are new, warm them up on a music signal for several days;
Check for strong reflections from side walls or the floor in front of the listener.
Distortions
From subjectivism we need to move on to technical concepts. It's worth starting with distortions. They are divided into two large groups: linear and nonlinear distortions. Linear distortion do not create new spectral components of the signal; they change only the amplitude and phase components. (They distort the frequency response and phase response, respectively.) Nonlinear distortion make changes to the signal spectrum. Their number in the signal is presented in the form of nonlinear distortion and intermodulation distortion coefficients.
Harmonic distortion factor (THD, THD - total harmonic distortion) is an indicator characterizing the degree to which the voltage or current shape differs from the ideal sinusoidal shape. In Russian: a sinusoid is supplied to the input. At the output, it does not resemble itself, since the path introduces changes in the form of additional harmonics. The degree of difference between the signal at the input and output is reflected by this coefficient.
Intermodulation distortion factor - this is a manifestation of amplitude nonlinearity, expressed in the form of modulation products that appear when a signal is applied, consisting of signals with frequencies f 1 And f 2(based on the recommendation of IEC 268-5, frequencies are taken for measurements f 1 and f 2, such that f 1 < f 2/8. You can take another relationship between frequencies). Intermodulation distortion is assessed quantitatively by spectral components with frequencies f 2±(n-1) f 1, where n=2,3,... At the system output, the number of extra harmonics is compared and the percentage of the spectrum they occupy is estimated. The result of the comparison is the intermodulation distortion coefficient. If measurements are carried out for several n (usually 2 and 3 are sufficient), then the final intermodulation distortion coefficient is calculated from the intermediate ones (for different n) by taking the square root of the sum of their squares.
Power
We can talk about it for a very long time, since there are many types of measured speaker powers.
A few axioms:
Volume does not depend only on power. It also depends on the sensitivity of the speaker itself. And for an acoustic system, sensitivity is determined by the sensitivity of the largest speaker, since it is the most sensitive;
the indicated maximum power does not mean that you can apply it to the system and the speakers will play perfectly. Everything is just more unpleasant. Maximum power for a long time is highly likely to damage something dynamically. Manufacturer's warranty! Power should be understood as an unattainable limit. Only less. Not equal, and certainly not more;
little of! At maximum power or close to it, the system will play extremely poorly, because distortion will increase to completely indecent values.
The power of the speaker system can be electrical or acoustic. It is unrealistic to see the acoustic power on a box with acoustics. Apparently, so as not to scare off the client with a small number. The fact is that the efficiency (efficiency factor) of the GG (loudspeaker head) in a very good case reaches 1%. The usual value is up to 0.5%. Thus, the acoustic power of a system can ideally be one hundredth of its electrical potential. Everything else is dissipated in the form of heat, spent on overcoming the elastic and viscous forces of the speaker.
The main types of powers that can be seen on acoustics are: RMS, PMPO. This is electrical power.
RMS(Root Mean Squared - root mean square value) - average value of the supplied electrical power. Power measured in this way has a meaning. It is measured by applying a sine wave with a frequency of 1000 Hz, limited from above by a given value of total harmonic distortion (THD). It is imperative to study what level of nonlinear distortion the manufacturer considered acceptable, so as not to be deceived. It may turn out that the system is stated at 20 watts per channel, but the measurements were carried out at 10% SOI. As a result, it is impossible to listen to acoustics at this power. Also, the speakers can play at RMS power for a long time.
PMPO(Peak Music Power Output - peak music output power). What is the benefit of a person knowing that his system may suffer a short, less than a second, low frequency sine wave with high power? However, manufacturers are very fond of this option. After all, on plastic speakers the size of a child’s fist there can be a proud number of 100 Watts. There were no healthy boxes of Soviet S-90s lying around! :) Oddly enough, such figures have very little relation to the real PMPO. Empirically (based on experience and observations) you can obtain approximately real watts. Let's take the Genius SPG-06 as an example (PMPO-120 Watt). It is necessary to divide PMPO into 10 (12 Watts) and 2 (number of channels). The output is 6 watts, which is similar to the real figure. Once again: this method is not scientific, but is based on the author’s observations. Usually works. In reality, this parameter is not so large, and the huge numbers are based only on the wild imagination of the marketing department.
Thiel-Small parameters
These parameters completely describe the speaker. There are parameters both constructive (area, mass of the moving system) and non-structural (which follow from the constructive ones). There are only 15 of them. In order to roughly imagine what kind of speaker is working in the column, four of them are enough.
Speaker resonant frequency Fs(Hz) - resonance frequency of a speaker operating without acoustic design. Depends on the mass of the moving system and the rigidity of the suspension. It is important to know, since below the resonant frequency the speaker practically does not sound (the sound pressure level drops strongly and sharply).
Equivalent Volume Vas(liters) - the useful volume of the housing required for the speaker to operate. Depends only on the diffuser area (Sd) and the flexibility of the suspension. It is important because, when working, the speaker relies not only on the suspension, but also on the air inside the box. If the pressure is not what is needed, then the speaker will not work perfectly.
Full quality factor Qts - the ratio of elastic and viscous forces in a moving dynamic system near the resonance frequency. The higher the quality factor, the higher the elasticity in the dynamics and the more readily it sounds at the resonant frequency. It consists of mechanical and electrical quality factors. Mechanical is the elasticity of the suspension and the corrugation of the centering washer. As usual, it is the corrugation that provides greater elasticity, and not the external suspensions. Mechanical quality factor - 10-15% of total quality factor. Everything else is the electrical quality factor formed by the magnet and the speaker coil.
DC resistance Re(Ohm). There is nothing special to explain here. Resistance of the head winding to direct current.
Mechanical quality factor Qms- the ratio of elastic and viscous forces of the speaker; elasticity is considered only for the mechanical elements of the speaker. It is made up of the elasticity of the suspension and the corrugation of the centering washer.
Electrical quality factor Qes- the ratio of elastic and viscous forces of the speaker, elastic forces arise in the electrical part of the speaker (magnet and coil).
Diffuser area Sd(m2) - measured, roughly speaking, with a ruler. It has no secret meaning.
Sensitivity SPL(dB) - sound pressure level developed by the loudspeaker. Measured at a distance of 1 meter with an input power of 1 Watt and a frequency of 1 kHz (typical). The higher the sensitivity, the louder the system plays. In a two-way or more-way system, the sensitivity is equal to the SPL of the most sensitive speaker (usually the bass mug).
Inductance Le(Henry) is the inductance of the speaker coil.
Impedance Z(Ohm) is a complex characteristic that appears not on direct current, but on alternating current. The fact is that in this case, the reactive elements suddenly begin to resist the current. Resistance depends on frequency. Thus, impedance is the ratio of the complex voltage amplitude and the complex current at a certain frequency. (Frequency dependent complex impedance, in other words).
Peak power Pe(Watt) is PMPO, which is discussed above.
Weight of the moving system mms(d) is the effective mass of the moving system, which includes the mass of the diffuser and the air oscillating with it.
Relative hardness Cms(meters/newton) - flexibility of the moving system of the loudspeaker head, displacement under the influence of mechanical load (for example, a finger that aims to poke the speaker). The higher the parameter, the softer the suspension.
Mechanical resistance Rms(kg/sec) - active mechanical resistance of the head. Everything that can provide mechanical resistance in the head is included here.
Motor power BL- the value of magnetic flux density multiplied by the length of the wire in the coil. This parameter is also called the power factor of the speaker. We can say that this is the power that will act on the diffuser from the magnet side.
All of the above parameters are closely interrelated. This is pretty obvious from the definitions. Here are the main dependencies:
Fs increases with increasing rigidity of the suspension and decreases with increasing mass of the moving system;
Vas decreases with increasing suspension rigidity and increases with increasing diffuser area;
Qts increases with increasing rigidity of the suspension and mass of the moving system and decreases with increasing power B.L..
So, now you are familiar with the basic theoretical apparatus necessary to understand articles on acoustic systems. Let's move on directly to the testing methodology used by the authors of our portal.
Testing methodology
Frequency response Measurement technique and interpretation
At the beginning of this section, we will deviate a little from the main topic and explain why all this is being done. First, we want to describe our own method for measuring frequency response so that the reader does not have any additional questions. Secondly, we will tell you in detail how to perceive the resulting graphs and what can be said from the given dependencies, as well as what should not be said. Let's start with the methodology.
Measurement microphone Nady CM-100
Our technique for measuring frequency response is quite traditional and differs little from the generally accepted principles of conducting detailed experiments. Actually, the complex itself consists of two parts: hardware and software. Let's start with a description of the real devices that are used in our work. As a measuring microphone, we use a high-precision condenser microphone Behringer ECM-8000 with an omnidirectional polar pattern (omnidirectional), which has quite good parameters at a relatively low price. So to speak, this is the “heart” of our system. This instrument is designed specifically for use with modern technology as part of budget measurement laboratories. We also have at our disposal a similar microphone, the Nady CM-100. The characteristics of both microphones practically repeat each other, however, we always indicate with which microphone a particular frequency response was measured. As an example, here are the stated technical characteristics of the Nady CM-100 microphone:
impedance: 600 Ohm;
sensitivity: -40 dB (0 dB = 1 V/Pa);
frequency range: 20-20000 Hz;
maximum sound pressure: 120 dB SPL;
power supply: phantom 15…48 V.
Frequency response of the measuring microphone
M-Audio AudioBuddy microphone preamplifier
We use an external compact solution, M-Audio AudioBuddy, as a microphone preamplifier. The AudioBuddy preamplifier is designed specifically for digital audio applications and is optimized for use with microphones that require phantom power. Plus, the user has independent outputs at his disposal: balanced or unbalanced TRS. The main parameters of the preamplifier are:
frequency range: 5-50,000 Hz;
microphone gain: 60 dB;
microphone input impedance: 1 kOhm;
instrument gain: 40 dB;
instrument input impedance: 100 kOhm;
power supply: 9 V AC, 300 mA.
Sound card ESI Juli@
For further analysis, the signal from the output of the amplifier is fed to the input of a computer audio interface, which uses an ESI Juli@ PCI card. This solution can easily be classified as a semi-professional or even entry-level professional device. Main parameters:
number of I/O: 4 inputs (2 analog, 2 digital), 6 outputs (2 analog, 4 digital);
ADC/DAC: 24-bit/192 kHz;
frequency range: 20 Hz - 21 kHz, +/- 0.5 dB;
dynamic range: ADC 114 dB, DAC 112 dB;
inputs: 2 analog, 2 digital (S/PDIF Coaxial);
outputs: 2 analog, 2 digital (S/PDIF Coaxial or Optical);
MIDI: 1 MIDI input and 1 MIDI output;
interface: PCI;
synchronization: MTC, S/PDIF;
Drivers: EWDM driver support for Windows 98SE/ME/2000 and XP, MAC OS 10.2 or older.
In general, the unevenness of the path of the entire system in the frequency range 20-20000 Hz lies within +/- 1...2 dB, so our measurements can be considered quite accurate. The main negative factor is that all measurements are carried out in an average living room with standard reverberation. The area of the room is 34 m2, the volume is 102 m3. The use of an anechoic chamber, naturally, increases the accuracy of the result obtained, but the cost of such a chamber is at least several tens of thousands of dollars, so only large manufacturers of acoustic systems or other very wealthy organizations can afford such a “luxury”. However, there are also tangible advantages to this: for example, the frequency response in a real room will always be far from the frequency response that was obtained by the manufacturer in the test chamber. Therefore, based on our results, we can draw some conclusions about the interaction of specific acoustics with the average room. This information is also very valuable, because any system will be operated in real conditions.
Popular utility RightMark Audio Analyzer
The second important point is the software part. We have several professional software packages at our disposal, such as RightMark Audio Analyzer ver. 5.5 (RMAA), TrueRTA ver. 3.3.2, LSPCad ver. 5.25, etc. As a rule, we use the convenient RMAA utility; provided it is freely distributed and constantly updated, it is very practical and provides high accuracy of measurements. In fact, it has already become a standard among test packages throughout the RuNet.
Program TrueRTA
Measuring module JustMLS programs LSPCAD
It would seem that any measurement should be carried out according to strictly established rules, but in the field of acoustics there are too many of these rules, and they often diverge somewhat from each other. For example, the basic standards and measurement methods are given in several very significant documents at once: outdated GOSTs of the USSR (GOST 16122-87 and GOST 23262-88), IEC recommendations (publications 268-5, 581-5 and 581-7), German DIN standard 45500, as well as American AES and EIA regulations.
We make our measurements as follows. The acoustic system (AS) is installed in the center of the room at the maximum distance from walls and three-dimensional objects; a high-quality stand 1 m high is used for installation. The microphone is installed at a distance of about a meter on a straight axis. The height is chosen in such a way that the microphone “looks” at approximately the central point between the midrange and tweeter speakers. The resulting frequency response is called the characteristic taken on the direct axis, and in classical electroacoustics it is considered one of the most important parameters. It is believed that the fidelity of reproduction directly depends on the unevenness of the frequency response. However, read about this below. We also always measure the angular characteristics of the system. Ideally, it is necessary to obtain a whole set of dependencies in the vertical and horizontal planes in increments of 10...15 degrees. Then it is quite reasonable to draw conclusions about the directional pattern of the speakers and give advice on the correct placement in space. In fact, the angular frequency response is no less important than the frequency response along the straight axis, since they determine the nature of the sound reaching the listener after reflection from the walls of the room. According to some reports, the share of reflections at the listening point reaches 80% or more. We also remove all possible characteristics of the path with all available frequency adjustments, modes such as 3D, etc.
Simplified flowchart of the measurement process
You can tell a lot from these graphs...
Subjective listening
So, the frequency response graphs have been obtained. What can you say after studying them in detail? In fact, a lot can be said, but it is impossible to unambiguously evaluate the system based on these dependencies. Not only is the frequency response not a very informative characteristic, and a whole series of additional measurements are required, for example, impulse response, transient response, cumulative spectrum attenuation, etc., but even from these comprehensive dependencies it is quite difficult to give an unambiguous assessment of acoustics. Strong evidence of this can be found in the official statement of the AES (Journal of AES, 1994) that subjective assessment is simply necessary to obtain a complete picture of the acoustic system in combination with objective measurements. In other words, a person can hear a certain artifact, but it is possible to understand where it comes from only by making a series of precise measurements. Sometimes measurements help to identify an insignificant defect that can easily slip past your ears when listening, and you can “catch” it only by focusing your attention on this particular range.
First, you need to break the entire frequency range into characteristic sections so that it is clear what we are talking about. Agree, when we say “mid frequencies”, it is not clear how much it is: 300 Hz or 1 kHz? Therefore, we suggest using a convenient division of the entire sound range into 10 octaves, described in the previous section.
Finally, we move directly to the moment of subjective description of sound. There are thousands of terms for assessing what is heard. The best option is to use some kind of documented system. And there is such a system, it is offered by the most authoritative publication with a half-century history, Stereophile. Relatively recently (in the early 90s of the last century), an acoustic dictionary, Audio Glossary, edited by Gordon Holt, was published. The dictionary contains an interpretation of more than 2000 concepts that in one way or another relate to sound. We propose to familiarize yourself with only a small part of them, which relates to the subjective description of sound in the translation by Alexander Belkanov (Magazine "Salon AV"):
ah-ax (rhymes with "rah" - Hurray). The coloring of vowels caused by a peak in the frequency response around 1000 Hz.
Airy - airiness. Refers to high frequencies that sound light, gentle, open, with a feeling of unlimited top end. A property of a system that has a very smooth response at high frequencies.
aw - (rhymes with "paw" [po:] - paw). The coloring of vowels caused by a peak in the frequency response around 450 Hz. Strives to emphasize and embellish the sound of large brass instruments (trombone, trumpet).
Boomy - read the word "boom" with a long "m". Characterizes an excess of mid-bass, often with a predominance of a narrow low-frequency band (very close to “one-note-bass” - bass on one note).
Boxy (literally “boxy”): 1) characterized by “oh” - the coloring of the vowels, as if the head is speaking inside the box; 2) used to describe the upper bass/low mids of speakers with excessive cabinet wall resonances.
Bright, brilliant - bright, with shine, sparkling. An often misused term in audio, it describes the degree of hardness of the edge of the sound being reproduced. Luminance refers to the energy contained in the 4-8 kHz band. This does not apply to the highest frequencies. All living sounds have brightness, the problem arises only when there is excess of it.
Buzz is a buzzing low-frequency sound that has a fluffy or sharp character due to some uncertainty.
Chesty - from chest (chest). A pronounced density or heaviness when reproducing a male voice due to excessive energy in the upper bass/lower midrange.
Closed-in (literally - hidden, closed). Needs openness, air and good detail. Closed-off sound is usually caused by HF roll-off above 10 kHz.
Cold - cold, stronger than cool - cool. Has some excess highs and weakened lows.
Coloration - coloring. An audible "signature" with which the reproducing system colors all signals passing through it.
Cool - cool. Moderately lacking in density and warmth due to monotonic decay starting at 150 Hz.
Crisp - crisp, clearly defined. Precisely localized and detailed, sometimes excessively due to the peak in the mid-HF range.
Cupped-hands - a mouthpiece made of palms. Coloration with a nasal sound or, in extreme cases, sound through a megaphone.
Dark - dark, gloomy (literally). Warm, soft, overly rich sound. It is perceived by ear as a clockwise slope of the frequency response throughout the entire range, so that the output level is attenuated with increasing frequency.
Dip (literally - immersion, failure). A narrow gap in the middle of a flat frequency response.
Discontinuity (literally - gap). Change in timbre or color during the transition of a signal from one head to another in multi-band acoustic systems.
Dished, dished-down - in the form of a saucer, an inverted saucer. Describes the frequency response with a failed middle. The sound has a lot of bass and high frequencies, the depth is exaggerated. Perception is usually lifeless.
Dry (literally - dry). Describes the quality of the bass: lean, lean, usually overdamped.
Dull (literally - dull, dull, boring, lethargic, depressed). Describes a lifeless, veiled sound. Same as “soft” - soft, but to a greater extent. An audible HF roll-off effect after 5 kHz.
her - rhymes with we. Coloration of vowels caused by a peak in the frequency response around 3.5 kHz.
eh - as in "bed". Coloration of vowels caused by a short rise in frequency response in the region of 2 kHz.
Extreme highs - ultra-high. The range of audible frequencies is above 10 kHz.
Fat (literally - plentiful, rich, fatty, oily). An audible effect of moderate redundancy in the mid and upper bass. Excessively warm, more "warm".
Forward, forwardness (literally - brought to the fore, moving forward). A reproduction quality that gives the impression that sound sources are closer than they were when recorded. Typically this is the result of a hump in the midrange plus the narrow directivity of the speakers.
Glare (literally - dazzling, sparkling). An unpleasant quality of hardness or brightness due to excessive low or mid-high energy.
Golden (literally - golden). A euphonious color, characterized by roundness, richness, and melody.
Hard (literally - hard, hard). Aspiring to steel, but not so piercing. This is often the result of a moderate hump around 6 kHz, sometimes caused by slight distortion.
Horn sound - horn sound made through a horn. "aw" coloring, characteristic of many acoustic systems that have a mid-frequency horn driver.
Hot (literally - hot). Sharp resonant surge in high frequencies.
Hum (literally - buzzing). Continuous "itching" at frequencies that are multiples of 50 Hz. Caused by the penetration of the main frequency of the power supply or its harmonics into the playback path.
Humped (literally - hunched over). Characterizes the sound pushed forward (in terms of spatial characteristics). The overall sound is sluggish and meager. Caused by a broad rise in the mid frequencies and a fairly early fall in the lows and highs.
ih - as in the word "bit". Coloration of vowels caused by a peak in the frequency response around 3.5 kHz.
Laid-back (literally - pushed back, pushed back). Depressed, distant sounding, with exaggerated depth, usually due to a saucer-shaped midrange.
Lean - thin, skinny, frail. The effect of a slight downward decline in frequency response, starting from 500 Hz. Less pronounced than “cool” - cool.
Light - light. The audible effect of tilting the frequency response counterclockwise relative to the middle. Compare with "dark" - dark.
Loose - loose, loose, unstable. Refers to poorly defined/washed out and poorly controlled bass. Problems with damping of the amplifier or dynamic drivers/acoustic design of speakers.
Lumpy (literally - lumpy). A sound characterized by some discontinuity in the frequency response in the lower part, starting from 1 kHz. Some areas appear bulging, others appear weakened.
Muffled - muted. It sounds very sluggish, dull, and has no high frequencies in the spectrum at all. The result is a roll-off of high frequencies above 2 kHz.
Nasal (literally - nasal, nasal). It sounds similar to talking with a stuffy or pinched nose. Similar to the coloring of the vowel "eh". In loudspeaker systems, this is often caused by a measured pressure peak in the upper midrange followed by a dip.
oh - pronunciation as in "toe". Vowel coloration caused by a wide spike in the frequency response in the region of 250 Hz.
One-note-bass - bass on one note. The predominance of one low note is a consequence of a sharp peak in the lower range. Usually caused by poor damping of the woofer head, room resonances can also appear.
oo - pronunciation as in the word "gloom". The coloring of the vowel is caused by a wide surge in the frequency response in the region of 120 Hz.
Power range - maximum energy range. The frequency range of approximately 200-500 Hz corresponds to the range of powerful orchestral instruments - brass.
Presence range (literally - range of presence). The lower part of the upper range is approximately 1-3 kHz, creating a sense of presence.
Reticent (literally - restrained). Moderately set back. Describes the sound of a system whose frequency response is saucer-shaped in the midrange. Opposite of forward.
Ringing (literally - ringing). Audible resonance effect: coloration, smeared/fuzzy sound, shrillness, buzzing. It has the nature of a narrow overshoot in the frequency response.
Seamless (literally - without a seam, from a single/solid piece). Has no noticeable discontinuities throughout the entire audible range.
Seismic - seismic. Describes the reproduction of low frequencies that make the floor seem to vibrate.
Sibilance (literally - whistling, hissing). Coloration emphasizing the vocal sound "s". It may be associated with a monotonic rise in the frequency response from 4-5 kHz or with a wide surge in the 4-8 kHz band.
Silvery - silvery. Somewhat harsh, but clear sound. It gives the flute, clarinet, and violas an edge, but the gong, bells, and triangles can be obtrusive and excessively sharp.
Sizzly - hissing, whistling. The frequency response rises in the region of 8 kHz, adding hissing (whistle) to all sounds, especially to the sound of cymbals and hissing in vocal parts.
Sodden, soggy (literally - wet, swollen with water). Describes loose and poorly defined bass. Creates a feeling of vagueness and illegibility in the lower range.
Solid-state sound - transistor sound, semiconductor sound. A combination of sonic qualities common to most solid-state amplifiers: deep, tight bass, slightly offset bright stage character and clearly defined, detailed treble.
Spitty (literally - spitting, snorting, hissing). A sharp “ts” is a coloring that overemphasizes musical overtones and sibilants. Similar to the surface noise of a vinyl record. Usually, the result is a sharp peak in the frequency response in the extreme HF region.
Steely - steely, steely. Describes shrillness, harshness, importunity. Similar to "hard", but to a greater extent.
Thick - fat, thick, dull. Describes a wet/dull or bulky, heavy bass sound.
Thin - liquid, frail, thinned. Very lacking in bass. The result is a strong, monotonous downward decay starting at 500 Hz.
Tizzy (literally - excitement, anxiety), “zz” and “ff” are the coloration of the sound of cymbals and vocal hisses, caused by an increase in the frequency response above 10 kHz. Similar to "wiry", but at higher frequencies.
Tonal quality - tonal quality. The accuracy/correctness with which the reproduced sound reproduces the timbres of the original instruments. (It seems to me that this term would be a good replacement for timbral resolution - A.B.).
Tube sound, tubey - sound due to the presence of tubes in the recording/playback path. A combination of sound qualities: richness (richness, liveliness, brightness of colors) and warmth, an excess of midrange and a lack of deep bass. Protruding image of the scene. The tops are smooth and thin.
Wiry - hard, tense. Causes irritation with distorted high frequencies. Similar to brushes hitting cymbals, but capable of coloring all sounds produced by the system.
Wooly - lethargic, vague, shaggy. Refers to loose, loose, poorly defined bass.
Zippy - lively, fast, energetic. Slight emphasis in the upper octaves.
So, now, looking at the given frequency response, you can characterize the sound with one or more terms from this list. The main thing is that the terms are systemic, and even an inexperienced reader can, by looking at their meaning, understand what the author wanted to say.
What material is the acoustics tested on? When choosing test material, we were guided by the principle of diversity (after all, everyone uses acoustics in completely different applications - cinema, music, games, not to mention different tastes in music) and the quality of the material. In this regard, the set of test disks traditionally includes:
DVDs with films and concert recordings in DTS and DD 5.1 formats;
discs with games for PC and Xbox 360 with high-quality soundtracks;
high-quality recorded CDs with music of various genres and genres;
MP3 discs with compressed music, material that is mainly listened to on MM acoustics;
special test CDs and HDCDs of audiophile quality.
Let's take a closer look at the test discs. Their purpose is to identify shortcomings in acoustic systems. There are test discs with a test signal and with musical material. Test signals are generated reference frequencies (allowing you to determine by ear the boundary values of the reproduced range), white and pink noise, a signal in phase and antiphase, and so on. The popular test disk seems to us the most interesting F.S.Q. (Fast Sound Quality) and Prime Test CD . Both of these discs, in addition to artificial signals, contain fragments of musical compositions.
The second category includes audiophile discs containing entire compositions, recorded in studios of the highest quality and mixed with precision. We use two licensed HDCD discs (recorded at 24-bit and 88 kHz sampling frequency) - Audiophile Reference II (First Impression Music) and HDCD Sampler (Reference Recordings), as well as a CD sampler of classical music, Reference Classic, from the same label, Reference Recordings .
AudiophileReference II(the disc allows you to evaluate such subjective characteristics as musical resolution, involvement, emotionality and presence, the depth of the nuances of the sound of various instruments. The musical material of the disc is classical, jazz and folk works, recorded with the highest quality and produced by the famous sound wizard Winston Ma. On the recording You can find magnificent vocals, powerful Chinese drums, deep string bass, and on a truly high-quality system you can get real listening pleasure.
HDCDSampler from Reference Recordings contains symphonic, chamber and jazz music. Using the example of his compositions, one can trace the ability of acoustic systems to build a musical stage, convey macro- and microdynamics, and the naturalness of the timbres of various instruments.
ReferenceClassic shows us the real strong point of Reference Recordings - chamber music recordings. The main purpose of the disc is to test the system for faithful reproduction of various timbres and the ability to create the correct stereo effect.
Z-characteristic. Measurement technique and interpretation
Surely even the most inexperienced reader knows that any dynamic head, and, consequently, the speaker system as a whole, has a constant resistance. This resistance can be regarded as direct current resistance. For household equipment, the most common numbers are 4 and 8 ohms. In automotive technology, speakers with a resistance of 2 ohms are often found. The resistance of good monitor headphones can reach hundreds of ohms. From a physics point of view, this resistance is determined by the properties of the conductor from which the coil is wound. However, speakers, like headphones, are designed to operate with audio frequency alternating current. It is clear that as the frequency changes, the complex resistance also changes. The dependence characterizing this change is called the Z-characteristic. The Z-characteristic is quite important to study because... It is with its help that you can draw clear conclusions about the correct matching of the speaker and amplifier, the correct calculation of the filter, etc. To remove this dependence, we use the LSPCad 5.25 software package, or more precisely, the JustMLS measuring module. Its capabilities are:
MLS Size (Maximum-Length Sequence): 32764,16384,8192 and 4096
FFT (Fast Fourier Transform) size: 8192, 1024 and 256 points used in different frequency bands
Sampling rates: 96000, 88200, 64000, 48000, 44100, 32000, 22050, 16000, 1025, 8000 Hz and user selectable Custom.
Window: Half Offset
Internal representation: From 5 Hz to 50000 Hz, 1000 frequency points with logarithmic periodicity.
To measure, you need to assemble a simple circuit: a reference resistor (in our case C2-29V-1) is connected in series from the speakers, and the signal from this divider is fed to the input of the sound card. The entire system (speaker/AC+resistor) is connected through an AF power amplifier to the output of the same sound card. We use the ESI Juli@ interface for these purposes. The program is very convenient because it does not require careful and lengthy setup. Just calibrate the sound levels and press the "Measure" button. In a split second we see the finished graph. Next comes its analysis; in each specific case we pursue different goals. So, when studying a low-frequency speaker, we are interested in the resonant frequency to check the correct choice of acoustic design. Knowing the resonant frequency of the high-frequency head allows you to analyze the correctness of the isolation filter solution. In the case of passive acoustics, we are interested in the characteristic as a whole: it should be as linear as possible, without sharp peaks and dips. So, for example, acoustics whose impedance sags below 2 ohms will not be to the taste of almost any amplifier. These things should be known and taken into account.
Nonlinear distortions. Measurement technique and interpretation
Total Harmonic Distortion (THD) is a critical factor when evaluating speakers, amplifiers, etc. This factor is due to the nonlinearity of the path, as a result of which additional harmonics appear in the signal spectrum. The nonlinear distortion factor (THD) is calculated as the ratio of the square of the fundamental harmonic to the square root of the sum of the squares of the additional harmonics. Typically, only the second and third harmonics are taken into account in calculations, although accuracy can be improved by taking into account all additional harmonics. For modern acoustic systems, the nonlinear distortion factor is normalized in several frequency bands. For example, for the zero complexity group according to GOST 23262-88, the requirements of which significantly exceed the minimum requirements of the IEC Hi-Fi class, the coefficient should not exceed 1.5% in the frequency band 250-2000 Hz and 1% in the frequency band 2-6.3 kHz. Dry numbers, of course, characterize the system as a whole, but the phrase “THE = 1%” still says little. A striking example: a tube amplifier with a non-linear distortion coefficient of about 10% can sound much better than a transistor amplifier with the same coefficient of less than 1%. The fact is that lamp distortion is mainly caused by those harmonics that are screened by auditory adaptation thresholds. Therefore, it is very important to analyze the spectrum of the signal as a whole, describing the values of certain harmonics.
This is what the signal spectrum of a specific acoustic looks like at a reference frequency of 5 kHz
In principle, you can look at the distribution of harmonics across the spectrum using any analyzer, both hardware and software. The same programs RMAA or TrueRTA do this without any problems. As a rule, we use the first one. The test signal is generated using a simple generator; several test points are used. For example, nonlinear distortions that increase at high frequencies significantly reduce the microdynamics of the musical image, and a system with high distortions as a whole can simply greatly distort the timbral balance, wheeze, have extraneous sounds, etc. Also, these measurements make it possible to evaluate the acoustics in more detail in combination with other measurements, and check the correctness of the calculation of the separation filters, because the nonlinear distortions of the speaker increase greatly outside its operating range.
Article structure
Here we will describe the structure of the article on acoustic systems. Despite the fact that we try to make reading as pleasant as possible and do not squeeze ourselves into a certain framework, articles are compiled taking into account this plan, so that the structure is clear and understandable.
1. Introduction
Here we write general information about the company (if we are getting to know it for the first time), general information about the product line (if we are taking it for a test for the first time), and we give an outline of the current state of the market. If the previous options are not suitable, we write about trends in the acoustics market, in design, etc. - so that 2-3 thousand characters are written (hereinafter - k). The type of acoustics is indicated (stereo, surround sound, triphonic, 5.1, etc.) and positioning on the market - as a multimedia gaming for a computer, universal, for listening to music for an entry-level home theater, passive for a home theater, etc.
Tactical and technical characteristics summarized in the table. Before the table with performance characteristics, we make a short introduction (for example, “we can expect serious YYY parameters from acoustics costing XXX”). The table type and set of parameters are as follows:
For systems2.0
|
Parameter |
Meaning |
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Output power, W (RMS) |
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External dimensions of speakers, WxDxH, mm |
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Gross weight, kg |
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Net weight, kg |
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Speaker diameter, mm |
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Speaker resistance, Ohm |
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Supply voltage, V |
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Frequency range, Hz |
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Frequency response unevenness in the operating range, +/- dB |
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Low frequency adjustment, dB |
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Crosstalk, dB |
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Signal to noise ratio, dB |
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Completeness |
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Average retail price, $ |
For systems2.1
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Parameter |
Meaning |
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Output power of satellites, W (RMS) |
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SOI at rated power, % |
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External dimensions of satellites, WxDxH, mm |
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Gross weight, kg |
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Net weight of satellites, kg |
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Subwoofer net weight, kg |
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Speaker diameter, mm |
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Speaker resistance, Ohm |
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Magnetic shielding, presence |
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Supply voltage, V |
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High frequency adjustment, dB |
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Low frequency adjustment, dB |
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Crosstalk, dB |
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Signal to noise ratio, dB |
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Completeness |
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Average retail price, $ |
For 5.1 systems
|
Parameter |
Meaning |
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Output power of front satellites, W (RMS) |
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Output power of rear satellites, W (RMS) |
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Center channel output power, W (RMS) |
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Subwoofer output power, W (RMS) |
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Total output power, W (RMS) |
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SOI at rated power, % |
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External dimensions of front satellites, WxLxH, mm |
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External dimensions of rear satellites, WxDxH, mm |
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External dimensions of the central channel, WxDxH, mm |
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External dimensions of the subwoofer, WxDxH, mm |
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Gross weight, kg |
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Net weight of front satellites, kg |
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Net weight of rear satellites, kg |
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Net weight of the central channel, kg |
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Subwoofer net weight, kg |
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Speaker diameter, mm |
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Speaker resistance, Ohm |
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Magnetic shielding, presence |
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Supply voltage, V |
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Frequency range of satellites, Hz |
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Subwoofer frequency range, Hz |
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Frequency response unevenness in the full operating range, +/- dB |
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High frequency adjustment, dB |
|
|
Low frequency adjustment, dB |
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Crosstalk, dB |
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Signal to noise ratio, dB |
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Completeness |
|
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Average retail price, $ |
We take the tables given as a basis; if additional data is available, we create additional columns; columns for which there is no data, we simply remove them. After the table with performance characteristics, some preliminary conclusions.
3. Packaging and accessories
We describe the delivery package and box, at least two photographs. Here we evaluate the completeness of the kit, describe the nature of the cables included in the kit, and, if possible, estimate their cross-section/diameter. We conclude that the kit corresponds to the price category, convenience and packaging design. We note the presence of a Russian-language operating manual and its completeness.
4. Design, ergonomics and functionality
We describe the first impression of the design. We note the nature of the materials, their thickness, quality factor. We evaluate design decisions in terms of their potential impact on sound (remembering to add the word “allegedly”). We evaluate the quality of workmanship, the presence of legs/spikes, grill/acoustic fabric in front of the diffusers. We are looking for fastenings, the possibility of installation on a stand/shelf/wall.
Describes ergonomics and impressions of working with acoustics (excluding listening). It is noted whether there is a click when turned on, whether the wires are long enough, and whether all controls are convenient to use. Implementation of controls (analog sliders or knobs, digital encoders, toggle switches, etc.) Several photographs of controls, remote control if available, photos of speakers in a setting or in comparison with ordinary objects. Convenience and speed of switching, the need to check phasing, whether the instructions help, etc. We note the effectiveness of magnetic shielding (on a CRT monitor or TV). We pay attention to additional inputs, operating modes (pseudo-surround sound, built-in FM tuner, etc.), service capabilities.
5. Design
We disassemble the speakers, if there is a subwoofer, then that too. We note the following design features:
Type of acoustic design (open, closed box, bass reflex, passive radiating, transmission line, etc.) + general photo of the internal structure;
Dimensions and internal volume of the case, assume the compatibility of the AO with the GG;
Location of loudspeaker heads (SG), method of attachment to the acoustic design;
Quality of internal installation, assembly, fastening + 1-2 photos with internal installation details;
Availability of mechanical damping, quality of its execution and materials used + photo;
The shape and dimensions of the bass reflex (if any), its location (estimated effect on the sound) and the manufacturer’s likely adaptations to eliminate jet noise + photo;
The quality of internal wiring, the presence of overload protection, proposals for modernization;
The GGs used are the type, material of manufacture (paper, impregnated silk, aluminum, plastic, etc.), the nature of the diffuser surface (conical, exponential surface, corrugated, with “stiffening ribs,” etc.) and the protective cap (flat , “acoustic bullet”, etc.), suspension (rubber, paper, etc.), degree of suspension rigidity), coil diameter, tweeter cooling, markings, resistance + photo of each GG;
Type of fastening of the wire to the speakers (detachable, screw clamps, spring clamps, banana clamps, etc.) + photo;
Signal cable connectors - types, quantity, quality.
We illustrate the following with diagrams and graphs:
Amplifier chip(s) - table with key characteristics, their analysis for compliance with performance characteristics and speakers, if possible - provide a graph of power versus SOI and a photo, maybe a photo of the radiator;
Power transformer - table with currents, type of transformer (torus, on W-shaped plates, etc.) indicating the total power in VA, conclusions about the availability of power supply reserve, the presence of a power filter, etc. + photo;
Separation filter - we sketch the circuit, indicate the order of the filter (and, accordingly, the attenuation of the signal), and draw a conclusion about its justification; application (if appropriate measurements are available), we calculate the cutoff frequency if we subsequently measure resonance and/or Z-characteristic;
We calculate the resonant frequency of the bass reflex, present the formula and justify its use.
6. Measurements
We make the following measurements and provide an analysis for each of them, making assumptions about the nature of the sound.
Axial frequency response of the column with detailed analysis;
Frequency response of speakers at angles of 30 and 45 degrees, analysis of the nature of speaker dispersion;
Frequency response of the subwoofer (if any) + total frequency response of systems, quality analysis; trifonic matching, influence of bass reflex resonance;
Axial frequency response depending on tone controls (if any);
Frequency response of the bass reflex, analysis;
Harmonic distortion spectrum;
Frequency response of speakers separately (for example, LF and HF), if necessary.
7. Audition
First, we give the first subjective assessment of the nature of the sound, indicating whether the volume is sufficient for various playback modes. We note the peculiarities of the acoustics in each of the typical applications - cinema (for 5.1 systems we focus on the quality of positioning), music and games. We indicate the type of listening room, its area and volume, as well as the degree of demands of the given acoustics on the room. Next, we analyze the sound of the speakers using the list of characteristics and terminology described above. We try to avoid subjective comments and, at every opportunity, make a reference to the measurement result that confirmed this or that sound feature. In general, all sound analysis is done in conjunction with measurements. Be sure to pay attention to the following parameters:
The nature of the acoustics in each of the key frequency ranges, the extent to which one or another range is emphasized;
The nature and quality of the stereo effect (the width of the stage, the positioning of sound sources and instruments on it); for 5.1 acoustics, a separate assessment of spatial positioning is given. Don’t forget to place the acoustics correctly (the angle to the front pair is 45 degrees, the distance is slightly greater than the stereo base, the rear pair is twice as close to the listener as the front pair, all speakers are at ear level);
Detail, sound transparency, “grain” (post-pulse activity at mid and high frequencies);
The presence of color and its character in different ranges, timbral balance and natural sound;
Clarity of sound attack (impulse response) and separately - subwoofer operation (if any);
Signal saturation with harmonics (warmth or coldness of sound);
Micro- and macrodynamics of sound, detail of background sounds, “openness” or “tightness” of sound (width of the dynamic range, quality of the transient response of the GG);
Optimal values for tone controls.
Here we give a general assessment of the acoustics, first of all, the compliance of the solutions used in it with the final result and price category. It is assessed whether the acoustics are successful, promising, and suitable as a “blank” for modifications. A list of pros and cons of the system is given.
Conclusion
The assiduous reader, having completed reading this article, probably learned something new and interesting for himself. We did not try to embrace the immensity and cover all possible aspects of the analysis of acoustic systems and, especially, sound theory; we will leave this to specialized publications, each of which has its own view of the line where physics ends and shamanism begins. But now all aspects of acoustics testing by the authors of our portal should be extremely clear. We never tire of repeating that sound is a subjective matter, and you cannot be guided by tests alone when choosing acoustics, but we hope that our reviews will greatly help you. Have a good sound, dear readers!
