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What is the evaluation standard for hifi headphones?

Hi-Fi is the abbreviation of High-Fidelity in English, literally translated as "high fidelity". Its definition is: a playback sound that is highly similar to the original sound. So what kind of audio equipment reproduces sound that is Hi-Fi? It is still difficult to draw firm conclusions so far. Professionals in the audio industry use various instruments and various means to detect various indicators to determine the Hi-Fi level of the equipment, while audio enthusiasts often use their own ears to judge whether the equipment reaches the Hi-Fi level in their minds. . To judge the high-fidelity level of the reproduced sound, not only high-performance equipment and software are required, but also a good listening environment. Therefore, there is still a difference between objective testing and subjective evaluation on how to correctly measure the Hi-Fi level of audio equipment.

Hi-Fi = high fidelity. The Hi-Fi system among audiophiles generally refers to audio equipment with higher technical specifications. The sky is the limit on Hi-Fi.

Hi-Fi sound systems can be divided into integrated, packaged and combined types in terms of structure. An integrated audio system assembles equipment and speakers with various functions into a chassis and cannot be disassembled at will. This type of machine is generally a low-end and popular machine. The packaged audio system is designed by the manufacturer to combine various pieces of equipment into a set, and each unit can be disassembled. The audio combination is to choose various types of equipment according to personal preferences and combine them freely.

The audio system mainly consists of the auditory system (human ears), hardware system (equipment), software system (signal source) and listening environment.

Audio source refers to equipment that converts magnetic signals or digital signals in audio source software into electrical signals. It mainly includes DVD, S-VCD, VCD, CD, tuner, deck and high-fidelity video Machine etc.

The power amplifier mainly amplifies the weak signal input from the audio source equipment and generates a current large enough to drive the speaker to reproduce the sound.

The speaker is the mouthpiece of a set of audio equipment. The final sound of the audio source software depends on the speaker. The quality of the reproduced sound of the audio equipment is completely expressed by the speaker. Therefore, the speaker plays a decisive role in the audio equipment.

[Edit this paragraph] What are the main technical indicators of the sound system?

The main technical indicators of the sound system include: frequency characteristics, signal-to-noise ratio, dynamic range, transient response, stereo separation, and stereo balance.

Frequency characteristics: the frequency range (frequency response) of audio equipment when played back and the relationship between signal amplitude and frequency (amplitude-frequency characteristics). The unit of amplitude is dB and the unit of frequency is Hz. The frequency response of the sound system should be at least 32-18000Hz, and the signal amplitude change within this frequency range should be less than 2dB.

Signal-to-noise ratio: The logarithm of the ratio of useful signal to noise at the same reference point. The signal-to-noise ratio at the speaker input point is 70dB. The human ear is almost inaudible one meter away from the speaker. Hi-Fi systems generally reach more than 100dB.

Dynamic range: The logarithm of the ratio of the maximum undistorted output power of the audio equipment during playback to the system noise output power at rest. Hi-Fi systems generally reach above 100dB.

Distortion: The degree of distortion of the audio source signal when played back by audio equipment. There are harmonic distortion, intermodulation distortion, and transient distortion. Hi-Fi system harmonic distortion is generally less than 1%.

Stereo separation: the separation of the left and right channels. Reflects the degree of crosstalk between the left and right channels.

Stereo balance: the difference in signal gain between the left and right channels.

[Edit this paragraph] What are the differences between Hi-Fi and Hi-End?

Generally speaking, Hi-Fi and Hi-end have excellent indicators in terms of conventional objective technical parameters. However, if we use these conventional technical parameters to distinguish Hi-Fi and Hi-end, we will inevitably be wrong. Conventional technical parameters are the basic means and methods to measure the quality of audio equipment. An excellent technical parameter is essential for both Hi-Fi and Hi-end. However, the sensitivity of people's hearing to technical parameters is limited. For example, a distortion difference of a few thousandths or an imbalance difference of a few tenths of a decibel is difficult for most people to detect.

However, whether they are designers and manufacturers of audio equipment or welding enthusiasts, they all have this experience in their own practice, that is, some technical parameters or technical characteristics other than conventional technical parameters have an important impact on The timbre and sound quality of the equipment have a certain impact. For example, the introduction method of negative feedback and the choice of negative feedback depth will have a great impact on the timbre and sound quality, but they have little to do with conventional technical parameters. It goes without saying that the audio equipment handles a signal with multiple frequency components in a wide frequency band and a large change in signal amplitude. It is difficult to express this signal with a simple mathematical model when it passes through a nonlinear system.

As far as the technical parameters of audio equipment are concerned, what ordinary Hi-Fi equipment pursues and guarantees are basically conventional technical parameters, and they often strive to achieve the highest possible indicators. In addition to conventional technical parameters, Hi-end equipment often pays attention to deeper technical parameters and technical characteristics.

Therefore, Hi-end equipment may not have any obvious advantages in terms of conventional technical parameters, but its subjective listening experience has left a deep impression on people.

There are many factors that affect the quality of equipment. In addition to perfect circuit design, the selection of manufacturing processes and materials is also critical. This can be said to be one of the differences between Hi-Fi and Hi-end. Generally speaking, Hi-Fi equipment is in high demand, and the design of the manufacturing process during the production process is often as simple as possible to reduce costs. The selection of components should also try to use varieties with higher performance and lower prices. Hi-end equipment is different, because the market for Hi-end is much smaller than Hi-Fi, and if the quality of the equipment is not good enough, users will not think it is Hi-end equipment. Therefore, Hi-end equipment attaches great importance to the manufacturing process, often paying great attention to the position of a wire and a solder joint. The original parts used are made of high-quality products from famous brands as much as possible. As for the appearance of the equipment, it is not a big deal. We often strive to have a harmonious and exquisite appearance, and even the mechanical center of gravity and mechanical vibration characteristics of the equipment are not ignored. In some audio publications, you often see words describing Hi-end equipment, such as "exhausted materials" when talking about components, "powerful image" when talking about appearance, and "exquisite" when talking about craftsmanship. Unparalleled". These words are indeed the objective characteristics of some current Hi-end equipment, but for the user, his pursuit is often more focused on the musical expression of Hi-end equipment. In other words, when pursuing Hi-end equipment, he pays more attention to Its sound is "quality".

Those Hi-end equipment with "powerful image", "exquisiteness" and "exhausted materials" are all expensive and far away from most music lovers. But products are determined by market demand. Among audio equipment, there is also a type of equipment that does not pursue a "powerful" image and "exquisite" craftsmanship, but uses the limited cost budget to improve the "quality" of the sound. superior. This makes its equipment with high-end equipment quality closer to more music lovers. For this type of high-quality equipment, we might as well call it "quasi" Hi-end equipment.

It is difficult to say that there is an obvious technical parameter boundary between Hi-Fi equipment and Hi-end equipment, nor can Hi-Fi and Hi-end be distinguished simply by appearance and market price. They are the same equipment. Whether it can be called Hi-end often needs to be evaluated based on many factors such as subjective listening experience, its own technical parameters, manufacturing process and price.

[Edit this paragraph] What elements should audio equipment have?

If you have visited the showrooms of some video stores or attended some audio exhibitions, you will find that the high-end audio equipment used for demonstration is really refreshing, they are eye-catching and exquisite. The craftsmanship is even more stunning, but when asked about the price, many people can’t close their mouths. Why do a pair of speakers, an amplifier or a record player cost hundreds of thousands of yuan? Do they really have this value?

This question is like asking: "Santana can run just as well, so why build a Porsche or Ferrari?" or "Ordinary violins can be bought for thousands or even hundreds of dollars, why? Why do masters such as Perlman use millions of instruments? Wouldn’t they be able to play without such expensive instruments? "Yes, high-end sports cars also have four wheels, and expensive violins are very cheap in appearance and structure." There is no difference between the two, there is no difference between the two in terms of basic functions, but what the high bidder is after is the ultimate performance. Cheap speakers can still play back music, but if you have to pay attention to perfect playback, you won't be able to achieve full success without using more advanced audio equipment. So to sum it up in one sentence, the difference between high-end speakers and ordinary speakers is not the functional difference, but the quality of the music played back that matters! In other words, the purpose of audio equipment is to reproduce the recording scene as the highest goal, hoping to simulate a fantasy-like space, where the expressions of performers and singers, and the shapes and positions of various instruments can be The clear distinction allows you to face the sound as if you are facing a musician, allowing you to communicate spiritually and move you endlessly.

So, what elements must audio equipment have to meet such demanding requirements? Please pay close attention to the following points:

1 Sound quality and timbre

Even the same type of musical instruments will have different sound performances. The most important part is the difference in sound quality. . The sound quality of audio equipment will also vary depending on the internal materials and the designer's tuning taste. Of course, noble sound quality and timbre are difficult to appear on ordinary musical instruments, and it is also difficult to appear on low-priced sound systems. What you need to pay attention to with cheap speakers is whether they can correctly express the differences between different instruments in the recording software. If the recording of a Steinway piano sounds no different from that of a cheap piano, then there is no way to fully appreciate the beauty of excellent recording. .

2 Distribution and control of volume in high, medium and low frequency bands

The frequency that the average human ear can hear is about 20Hz-20KHz, which is a quite wide range. The equipment should try its best to emit sounds in this complete frequency range, so that the performance will be better.

What is usually more difficult to express is the high and low ends, especially the lower low frequency parts. Since the human ear is relatively insensitive to these frequency parts, they require stronger energy, and stronger energy requires a lot of power. It is difficult for large, not high-end equipment to truly reproduce them perfectly.

The so-called capacity distribution of high, medium and low frequency bands refers to the amount of each frequency band within the frequency range that the equipment can emit. Some equipment has more high-frequency bands, some have a stronger sense of low-frequency, and some mid-range vocals are particularly full, but the volume in the high and low bands is not that much. In short, no one is enough, which forms the characteristics of various types of speakers in terms of confidence.

It should be noted that the amount of volume in each frequency band is not absolutely good or bad. The important thing is to achieve a balance after the overall mix. Don't have any one frequency band that stands out in particular, which will make it unbearable to listen to. . As for the control of each frequency band, it indicates the quality of it. Similarly, perfect low-frequency control is relatively difficult to obtain. Many equipment may have a lot of low-frequency volume, but poor control. This kind of low-frequency sounds at first glance. It is very "soft", but due to the lack of control over how to freely expand and expand it, it will appear weak, not full, not fully elastic, and will overflow into the space. If you listen to it for a long time, you will feel nauseated. Of course, the better the sound. , the control in each frequency band will be better, and the performance will often be excellent.

3 Sound field performance

Sound field performance is very important and can be said to be the primary condition for live reproduction. So what exactly is a sound field? The so-called sound field is the range in which the sound emitted by the two speakers can be condensed and formed. Usually, if the two speakers are placed appropriately (including the distance from the back wall and side walls, the height of the speakers and the angle of inward tilt, etc.) A concrete sound field will emerge. You can even "see" the size, position and shape of each sounding instrument and human voice behind the speaker. This is the sound field!

If the speaker is not adjusted to the best position in the listening space, then you can only hear the sound, and you will not be able to have the fun of "seeing through" the three-dimensional sound field, let alone "live reproduction". realm.

The performance of the sound field not only includes height, depth and width, but also includes the mutual relationship between the "objects" in the sound field, which is the clear relationship between far and near, depth, front and back, height and low. Taking the singing of a choir as an example, you should not only hear the sound of a voice, but also be able to distinguish the height and distance between the actors in the front and rear rows, which is commonly referred to as "level". It is not nonsense that some "high-level" audiophiles can "count" the number of "heads" in high-quality chorus recordings after carefully adjusting the positioning of super speakers. Usually the size and shape of the sound field will vary due to different recordings. When playing some software that has an amazingly deep and wide sound field, it will also feel like the sound field is larger than the actual space.

In addition, it should be noted that a complete sound field is not just about seeing the individual sounds, but also the size and shape of the space in which these sounders exist. For example, recording in a church will have the feeling that the hall is higher and the reverberation echo of the sound is longer. Live recording in jazz clubs, stadiums, etc. should also give the listener a different spatial experience.

In short, the concept of sound field performance contains almost all the meanings of words such as "positioning", "level", "depth and width", "sense of space" and "reverberation" that audiophiles often talk about.

4 Transparency and Analytical Power

When your sound system can already have a sound field concretely formed, first of all, congratulations on having crossed the threshold of Hi-Fi. The next step is to improve the transparency and analysis of the field. What is transparency? There is a good metaphor that can illustrate the problem. It is like looking at the scenery outside the window through glass. If the glass is dirty, it will reduce our visual effect. What we expect is of course that the cleaner the glass, the better, or even no glass. In this way We can see everything at a glance. The better the transparency of the same sound system, the easier it is for the listener to be immersed in the music, and there will be no hazy feeling like looking at flowers in the fog or looking at the moon in the water (of course, if the music wants to create such an effect, It’s up to the sound engineer). As for analytical skills? In terms of vision, it is like a lens with powerful resolution, which can take photos that are clearer than what the human eye can see, and can even reproduce the pigmentation of the skin and the size of the pores. The same is true for audio equipment. , good analytical skills can describe the ups and downs and patchwork details in the music very clearly, down to the smallest detail.

Even if a sheet of music falls softly to the ground while a large section of string instruments is playing in unison, you can still hear it!

5 Imagery and Body Sense

It is not enough to “see” the size, position and shape of each sounding instrument in the sound field. Further requirements are required. The shape of the sounding body should be condensed and should not feel loose. At the same time, the sounding body should not feel thin, but should have a corresponding thickness, like a soprano standing in front of you, or a tall and upright If the cello reproduced in the sound field is just a flat piece, that would be completely wrong!

6 The size ratio of musical instruments and vocals

Each sounding instrument and vocals should have an appropriate and accurate size ratio to each other. Drums cannot occupy the entire sound field with just one strike. It cannot happen that the violin is bigger than the piano; when some audio equipment plays vocal discs, the mouth shape of the soloist is out of proportion, and the big mouth sounds like it can swallow the entire band. With such a sound, even No matter how good the performance is in other aspects, it is impossible for the listener to feel as if he is at the scene. Of course, it is difficult to achieve this. This is a state that can only be achieved by extremely excellent Hi-End audio and first-class tuning skills.

7 A sense of life

A sense of life? A sense of life is a vivid feeling that is not rigid and feels like life. Music has incomparable vitality in audio equipment, and the artist's performance is full of vitality. When it should be fast, it will not lose its energy, and when it should be slow, it will not stop the car. We often talk about the performance of "dynamic" and "transient". In the final analysis, what these professional technical terms refer to is the comprehensive expression of audio life. Just imagine: if a piece of audio equipment or a record recording cannot allow you to easily feel the rhythm of the rhythm, the ups and downs of the melody, and the jumping and flying of the notes, naturally it cannot clearly express the quiet harmony of chamber music and the majesty of the symphony. , the passion of jazz, so how can you experience the souls of the musicians and enter their emotional world?

8 Overall balance

If a sound system performs quite well in all the above aspects, but combined it gives people a disharmonious feeling, just like each musician in the band. If you only care about expressing yourself and don't care about others, the result will be unbearable. In fact, it is quite simple to know whether the overall balance of a sound system is excellent. As long as it allows you to listen to it again and again for a long time, instead of becoming impatient, it makes you reluctant to turn off the phone and leave. That's right. ! Of course, this also means that it has a very good "musical taste", that is to say, this kind of equipment and music are naturally integrated, and it is completely tailor-made for music and art. Such a speaker has almost the same attributes as a musical instrument. It is hard to find, and it feels outrageous!

Okay, are so many elements already dazzling you? In fact, as long as you remember that the better the sound, the more people can feel the living music, just like the beauty and dynamics obtained at the scene, that is enough. Knowing this, I hope that you will no longer be shocked when you see sky-high-priced Hi-End equipment in the future, and at the same time, I hope that when you read reports about Hi-Fi, you will have a clear understanding and no longer be confused. Because you already know, what are enthusiasts constantly pursuing? Yes, it’s just getting closer and closer to art.