Speaker, what is hi-fi
The main technical performance
Due to the combination of multiple speakers for playback inside the speaker, the quality of the speakers, crossovers, cabinets and other components all play a decisive role in the performance of the speaker. Due to many changes, its performance parameters are There is a certain difference between a simple speaker, and the main technical performance of a speaker generally has the following items.
1. Rated impedance
The impedance of a speaker is generally determined by the rated impedance of the speakers that make up the speaker, but the impedance of the speaker is much more complicated than the concept of the impedance of a simple speaker, because the speakers in the speaker are of many varieties, high, medium, and low speakers. It is impossible for the performance to be exactly the same, and many factors such as the frequency divider and the cabinet structure and the materials used are added. Therefore, when analyzing the impedance characteristics of the speaker, many considerations are needed.
As mentioned above, due to the diversity of the internal structure of the speaker, its distortion is also composed of multiple factors. When making a speaker for trial listening, the cause of the distortion cannot be found from the speaker or one aspect alone. It should be considered from multiple angles. At the same time, the distortion of the output signal of the power amplifier cannot be ignored.
3. Rated frequency and effective frequency range
The rated frequency range of a speaker is generally specified in the product standard, and the frequency range that the speaker can actually achieve is called the effective frequency range.
Generally, in an ideal state, the frequency range that the speaker can reach is 16 Hz ~ 20000 Hz, but the frequency range that can be actually achieved is generally 40 Hz ~ 20000 Hz.
4. Characteristic sensitivity
The characteristic sensitivity of the speaker is the same as that of the speaker, which is equivalent to the voltage generated on the reference axis one meter away from the reference point when the pink noise signal voltage of 1 watt of electric power is at the rated impedance. The characteristic sensitivity uses "microbar" as the unit, and the characteristic sensitivity level uses "decibel" as the unit.
In addition, according to the international GB9396-88 test standard and GB9399-88 technical standard, there are also indicators such as the maximum sound pressure level, the rated maximum noise power, and the rated long-term maximum noise power. These indicators have little to do with amateur producers and are used in amateurs. It is difficult to detect under circumstances, so I won’t introduce it here.
In addition, some technical parameters in some imported speakers or speakers are marked in English. In order to facilitate the identification of the producer, the Chinese meanings of the common speakers and speakers in English are given here.
nominal impedance－nominal impedance
nominum power－nominal power
transient response-transient response
DC resistance－DC resistance
2-way system－2 frequency division system
floor standing－Floor speakers
vented box－inverted speaker
sealed(closed)box－closed sound box
voice coil－voice coil
voice coil inductance－voice coil inductance
voice coil diameter－voice coil diameter
magnet dimension－magnet size
volume equivalent-equivalent volume
What is high-fidelity audio? What is its connotation?
In the past years, high-fidelity sound has been familiar to people. It is precisely because of the basic composition system of high-fidelity sound ─ ─ audio equipment, power amplifiers, speakers that the reproduction of music has brought many audio enthusiasts and families. Happiness and enjoyment enable people to understand the connotation of music; cultivate their own sentiments; express the emotions of the soul, as the famous musician Xian Xinghai said, "Music is the greatest joy in life; music is the life's A clear spring; music is a melting pot of temperament."
With the continuous development of television technology, audio technology, and digital technology, as well as the continuous improvement of people’s living standards, the home theater boom that has risen in recent years has risen one after another. People are no longer satisfied with the pure appreciation of music in the past. It is to move the movie theater's replay effect with the integration of audio and video home to enjoy the wonderful and high-quality pictures; to listen to the replay effect of "quiet like a ghost, moving like thunder". Audio equipment has also changed from the past three-piece set (audio source, power amplifier, speaker) to a complicated high-definition large-screen TV, projector, VCD, CVD, SCVD, DVD, Dolby Surround system, SRS system, AC -3 system and DTS system and so on.
Due to the continuous emergence of new technologies and new types of equipment for various new types of home theaters, there are many types of audio equipment in the market. Audio enthusiasts and ordinary families are often asked by audio equipment stores when configuring and purchasing home theater audio equipment. The equipment is dazzling, and there is no way to start, often investing a lot of money and not getting a better playback effect. The main reason is that buyers of ordinary home theater systems do not have a clear understanding of the characteristics and differences between high-fidelity audio systems and home courtyard audio systems, and it is easier to confuse the two.
What is high-fidelity audio equipment? Friends who love audio can often see the English label "Hi-Fi" in audio magazines or audio equipment. It is the abbreviation of "High-Fidelity" in English, literally translated as "sound that is highly similar to the original sound". The sound system means "high-fidelity", which means that the sound reproduced by the audio equipment is highly similar to the sound emitted by the sound source recorded at the recording site. This type of equipment is called high-fidelity audio equipment. Or high-fidelity sound system. In some articles commenting on the sound reproduction effect of high-fidelity audio systems, it is often seen that the reproduction sound of equipment is described as "authentic", which is actually a description of the fidelity of the reproduction sound of the high-fidelity audio system.
High-fidelity audio is mainly composed of audio source system, pre-amplifier, power amplifier and speaker system. It can be seen from the figure that the composition of the high-fidelity audio system is relatively simple, with only one main line from beginning to end, and the design of the high-fidelity audio system equipment circuit is based on the principle of "simplicity first".
In the circuit design of high-fidelity audio systems, it is generally necessary to consider the simplicity of the circuit part, and minimize the amplification links, various components and switches in the circuit to reduce its impact on the audio signal. If there are more amplification links in the circuit, the waveform of the signal will change in geometry after the signal is input from the input end to the output end. This change in form is the distortion of the signal. Due to the quality of the components used, the circuit structure of the amplifier, the quality of the power supply and other factors, the amplifier will more or less have a certain impact on the amplified signal. If there are more amplification links in the entire circuit, correspondingly The greater the distortion, the higher the fidelity of the equipment's playback sound.
In addition, audio enthusiasts can generally find that there are more various function switches on the panels of some middle and low-end audio equipment, but the more high-end equipment, the fewer switches on the panel, and some power amplifiers only A power switch and volume control switch. For friends who have just come into contact with audio equipment, they may think that this type of equipment is too simple. The more various functions, the more complex the internal circuit of the equipment, and the higher the grade. In fact, it is not the case. The signal is transmitted in the circuit. One more switch is equivalent to putting a resistor in the circuit. As we all know, resistance has an obstructive effect on the movement of electric charges. Although some equipment switches or jacks are plated with 24K gold, the resistivity is small, but there is still a certain resistance value. If a certain number of various switches are added to the circuit, then it will have a certain influence on the signal transmission, especially on the smaller signals. Some audiophiles often feel that some subtle changes in the sound can be heard on this set of equipment, but not on another set of equipment. Part of the reason is here. Of course, other factors such as the circuit structure, the quality of the selected components, etc. can also cause the loss of tiny signals. In some low-end popular audio equipment, manufacturers have designed more function switches on the machine for the convenience of most consumers. This type of equipment has poor performance on some subtle changes in signals.
To sum up, the more concise the circuit of high-fidelity audio is, the smaller the loss of the electrical signal during transmission, the smaller the influence of the circuit on the electrical signal, the smaller the distortion, and the greater the quality of the reproduced sound. it is good. When making high-fidelity audio systems, we pay more attention to the materials used. For example, the signal output and input jacks use gold-plated non-magnetic jacks; the signal output lines are made of high-purity oxygen-free copper materials; the final output uses Some well-known dedicated audio pairs, etc. From the point of view of its production process, the high-fidelity audio system pays great attention to the arrangement, orientation and welding quality of internal components. For example, the pre-amplification part and the post-amplification part are isolated from each other, and the "ground" in the circuit board is used to amplify small signals. The circuit is shielded and isolated, etc. These factors have a certain impact on the playback effect of the equipment. If a certain equipment only pays attention to the selection of components and does not pay attention to its production process, its playback sound will definitely be affected.
From the perspective of replay sound, the high-fidelity audio system pays great attention to the connotation and details of the music. Through the replay of the equipment, the profound meaning of the music can be expressed, and the emotional communication with the audience can be generated during the replay. It should be able to express the subtle sounds in the music. For example, it can often be seen from audio reviews articles that when the equipment is replaying the music played by the violin, it will produce a "loose fragrance". Although this statement is a bit exaggerated, it shows that the equipment combines the pony tail of the violin bow with each other. The faint sound produced by the friction of a string is fully revealed. Most friends who like music know our famous violin concerto "Liang Shanbo and Zhu Yingtai". If you use a high-fidelity sound system to replay this piece, you can use it from the twenty minutes of violin performance. Appreciators experience the whole process of the development of the love tragedy between Liang Shanpo and Zhu Yingtai, which can easily resonate with the appreciator, bringing the appreciator to a fairy who "a rainbow of thousands of miles and hundreds of flowers bloom, two pairs of butterflies among the flowers, and thousands of generations are not separated." The realm makes people cry. Some more senior audio enthusiasts have mostly heard the CD film "Will it alone" published by the Hong Kong Hugo Company. Through the playback of the equipment, the listener seems to be in a remote, ethereal, and indefinite world. This is the effect of high-fidelity audio equipment on music. Connotation performance.