The main features of digital audio
1, high signal-to-noise ratio
Digital audio recording form is a binary code, playback only need to determine the "0" or "1". Therefore, the noise of the recording medium on the playback of the signal-to-noise ratio has almost no effect. The analog audio recording form is a continuous sound signal, in the process of recording and playback will be affected by such as tape noise, to be superimposed on the sound signal and make the sound quality deterioration, although the analog audio in the noise reduction measures, but can not be eliminated fundamentally.
2, low distortion
In the analog audio recording and playback process, the nonlinearity of the magnetic head will be introduced into the distortion, which must take measures such as AC bias recording, but the distortion still exists. In digital audio, the magnetic head only works in the magnetic saturation or non-magnetic two states, that is, 1 or 0, there is no linear requirement for the magnetic head.
3, good repeatability
Digital audio equipment by many copies and playback, the sound quality will not deteriorate. Traditional analog cassette recording, each re-recorded once, the noise recorded on the tape should be increased, resulting in each re-recorded to reduce the signal-to-noise ratio of about 3 dB, the sub-tape is not as good as the master tape, the Sun tape is not as good as the sub-tape, the quality of the sound degradation by and by.
4, shake rate is small
Digital audio playback system due to the role of time-based correction circuit, rotating system, drive system instability will not cause shake, and therefore do not have to ask for precision mechanical systems like analog records.
5, adaptable
Digital audio is recorded in binary code, a variety of processing can be carried out as a numerical operation, and can not change the hardware, only software operation, easy to control the microcomputer, so adaptable.
6, easy to integrate
Because of the digital, thus facilitating the use of ultra-large-scale integrated circuits, and make the whole machine easy to debug, stable performance, high reliability, and convenient for mass production, can reduce costs. Flat panel audio is composed of audio input device, signal amplifier (amplifier) and speakers, is a complete set of systems, through the exciter (driver) to stimulate the bending wave in the sound emitting plate and sound. After several years of market expansion in the industry, has been widely used in: home theater systems, background music systems, multimedia sound systems, public **** broadcasting system.
Advantages
1. Very good directivity. Generally with traditional speakers composed of speakers, directionality is very poor, you must stand in front of the speaker, in order to hear a more perfect sound, especially the treble part; and if you stand in the side of the speaker, may be some background or accompaniment sound can not be heard; if you stand in the back of the speaker, may be that sweet song, has become reluctant to appreciate the sound of the voice. The flat panel speakers do not have the above problems exist, no matter where you stand, you can appreciate the complete, real sound;
2. sound attenuation is small. Traditional speakers, when you lean too close to find the sound is very large, and a little farther away, you feel the sound is much smaller. Flat panel speakers do not have the above problem, whether you are in close proximity or a little farther away, the size of the sound heard does not have a big difference;
3. The sound of the fidelity of the higher. General traditional speaker, it is the shape of the acoustic cone, when it vibrates to send out the sound, often the sound will be concentrated in the throat, after compression, and then spread out, and people hear the sound, is after compression and deformation of the sound. Flat-panel speakers will not have the above problems, only because people used to listen to too much distortion, so once exposed to flat-panel audio, the beginning of listening will feel it is very ordinary, and then tend to be its natural performance and y attracted;
4. Due to the special structure of the flat speaker, the composition of the speaker can be placed in any position, unlike traditional speakers, due to the placement of different positions, hear the effect is very different; Classification
Combination of audio can be generally divided into a mini combination of audio and home theater sets.
Commonly referred to as a combination of audio has a desktop combination of audio and floor-standing combination of audio two categories. Because of the requirements of the combination of audio has a relatively high quality of sound, so its two speakers are generally larger.
By the structure of the host (layers), the audio has a one-piece and layered two categories. In the one-piece combination stereo, its various parts of the circuit (including the jukebox) are in a shell, this structure is generally used in low-grade combination stereo. In the layered combination of audio, according to the different grades of the machine is divided into different layers. Layers more combination of audio: a phonograph layer, a CD player layer, a tuner layer, a double card recording and playback seat layer, a tone controller layer, the main power amplifier layer. In the combination of less layered audio, the electric phonograph, CD player each divided into a layer, the other for a layer.
The development trend
Miniaturization, digitalization, specialization, film and television is the inevitable development trend of home audio.
Miniaturized audio. Miniature desktop combination stereo has a long history of development, more than 10 years ago there have been advanced ultra-small combination stereo. However, due to the listening speakers, stereo record player, recording card holder is not well resolved, so it has been stuck in a lower grade. In order to create a compact audio world, not only from the amplifier, control components, left and right speakers, but also from the tuner, CD phonograph and recording deck together.
Digital audio. Digital technology is a new technology, so digital audio in the solution to the distortion of analog audio noise developed. After the audio used digital technology, the digital signal recorded from the sampling frequency to quantize the characteristics, there is a clear resolution, there is no color jitter, get is a very clear image. And can be interchanged with the upper computer, which is incomparable with analog recording and playback equipment. Digital recording can be time, name, address together with the tape, using a miniature keyboard to complete the cataloging work, replace the track number, coupled with the remote control function, so that you can automatically search for the desired track, easy to use. Integration of film and television listening equipment. Digital audio with the development of electro-acoustic technology, film and television technology, computer technology, they can constitute a multimedia film and television audio system in the family as a whole. Such a system, can hear a variety of inputs in the input side to add a variety of needed signal input and function conversion, through computer processing can make the crowd see a variety of images and hear a variety of sounds.
Ultra-thin flat panel speakers, the emergence of flat-panel audio so that the family combination (home theater, background music) to the ultra-thin direction has become possible since 1998 to 2012 flat-panel audio has gone through several stages of development, the introduction of flat-panel audio in 1998 Sanno to the Hualong Dixing (DS), Tovic (TVC) inheritance and development, to the 2008 Chengdu Tianxiang (HVS) developed China's own flat-panel articulation technology. ) developed China's own flat-panel sound technology VT called "the fifth generation of flat-panel sound technology", the development of flat-panel audio technology in China is becoming more and more mature, thin mural ultra-thin audio in the family tends to use the maturation!
Embedded audio, embedded audio appeared in 1998 in Chengdu Fuyun (FREENOTE), after more than a decade of development, embedded audio in the "family central network sound system", "embedded home theater" Chengdu Tianxiang (HVS) combined with flat-panel speakers and embedded audio strengths, developed a new generation of home audio system "home health audio system", for the development of home audio to make a tentative step! Loudness
Professional audio acoustic characteristics not only to meet the national standards of acoustic characteristics indicators, but also to meet the subjective listening requirements, because the acoustic characteristics indicators can not fully reflect the actual sound effect, the sound is ultimately good or bad by the subjective listening to the human audio feeling to decide, in the acoustic design, electro-acoustic and acoustic design should be a good match to meet the following subjective listening requirements: the appropriate loudness.
Loudness is the actual listening to the intensity of the feeling, it has a direct relationship with the maximum sound pressure level of the sound reinforcement system indicators, for the performance, only to achieve sufficient loudness, in order to make the sound effects to be fully expressed. System output power, speaker placement will directly determine the loudness of the listening area state: high definition.
Fullness
When used as a speech, must ensure the clarity of the language, if people can not hear the speaker's language, will affect the effect of the speech. Therefore, in the electro-acoustic system design to give full consideration to improve the clarity of speech: enough fullness.
The performance effect with good fullness can make the human voice full, thick, lively music sound. In the electro-acoustic system, only through the use of audio peripheral equipment for effective processing of sound signals and reasonable selection of speakers these measures, the sound of the fullness of the requirements can be achieved.
Application
Sound reinforcement system acoustic characteristics of computer-aided design is the use of modern technology to engage in engineering design is an ideal method of high precision, high efficiency, and more importantly, do not have to wait until the end of the installation and commissioning will be able to know the results of the engineering design. Acoustic characteristics of the computer design system has a very good credibility and accuracy, in the input hall sound data is accurate enough, its calculated data and the final electro-acoustic measurements compared to the error can be controlled within decibels. For engineering design and installation and commissioning, this is already enough, at the same time it also has a very good design and installation and commissioning guidance, which has been well verified in the previous engineering design. The use of acoustic CAD computer system to design and calculate the hall, stadium (field), multi-purpose hall, lecture hall sound reinforcement system acoustic characteristics, it means that, without waiting for the system installation, commissioning and measurement is completed, you can know the design and installation and commissioning results. In other words, based on the design of the audio system and design calculations given by the program, has clearly seen the system's expected acoustic characteristics of the sound reinforcement system. Mini-speaker (mini-speaker) is a kind of micro-audio, many friends also call it "USB audio", USB interface to connect to the computer or USB jack, small, portable, novel style. Mini stereo can be connected to most of the audio output devices, such as MP3, MP4, MP5, cell phones, computers, etc. (some devices may need to be adapted to the interface). The shape design is simple and fashionable, small and exquisite, with many varieties. The lithium battery power supply of the body can be carried around. High power output is also suitable for outdoor use. Combination of mini audio is more suitable for placing at home.
Features
1, compact size, easy to carry, cool appearance, trendy fashion, personalized color matching, fresh and natural. Size specifications of the largest not more than a soccer ball, the smallest as the size of an egg;
2. Set amplifier, battery, dual speakers in one, the first patented technology to expand the telescopic expansion *** sound cavity, to solve the mini-speaker *** sound cavity narrow problem, breaking decades of speaker specifications limitations, compressed to the limit;
3. Do not need a long audio line, do not need external power supply, whether it is the mountains and rivers like fresh rhythms, or passionate DJ dance music, can be shown to the fullest!
4, the design is simple and clear, easy to use. The use of USB standard interface power supply and audio input, driver-free USB interface plug and play, fully compatible with WINDOW 95 98 ME 2000 and XP operating system. With 3.5mm stereo audio input interface link notebook, desktop PC, cell phones, PSP, Walkman, MD, Mp3, Pocket PC, PDA, Mp4, repeater, iPod, cell phones and other devices;
5, mini speakers only need to be connected to a laptop computer, cell phones and other devices, without the need for power supply, you can play beautiful music. Some speakers are equipped with a high-capacity lithium battery inside, the product can play 5-8 hours of music. Dual power supply mode is more durable.
6, portable performance is suitable for outdoor sports explorers, recreation, cycling outdoor sportsmen, also suitable for computer amplification, as a computer small speaker. In short, the mini small speakers because of the small size of the playback time, the external speaker sound, unlike the traditional MP3 need to bring earplugs, hurt the eardrums, has been more and more widely loved by people! Especially sports small speakers, bicycle audio and so on! Selection guidelines
Since the use of desktop stereo clear location and purpose of use, so we can initially judge the desktop stereo most of the cases are played on the radio, pop music and other vocal content, so for the stereo speakers do not have to work in the frequency band requires too low. Usually the lowest performance frequency of the audio system can be selected in the 40Hz above, of course, this is only one unit for each speaker.
If each speaker can be guaranteed two units (also coaxial speakers bass and treble embedded in the speaker), then the sound effect will be much more perfect. It's as if one instrument is never as expressive as an orchestra.
The layout of desktop audio
Although desktop audio, but some desktop audio speakers can be installed separately. So how do you lay out the speakers in a split installation?
Maybe you will say, a **** just two speakers, but also to talk about what layout? Of course, if your speakers are placed in the corner or your speakers are placed in the center of one side of the room, to achieve the sound effect is very different. Generally speaking, the two speakers of a small desktop stereo are recommended to be placed closest to the listening position, on an axis of symmetry in the room. The distance between the two speakers should not be too far, otherwise the power of the two speakers of the desktop stereo, it is difficult to generate a balanced sound field.
Because it is not a professional listening room with sound-absorbing structures, it is best to reduce the number of times the sound is reflected back and forth in the room, to prevent too many reflections because of the noise caused by the increased number of times, but also to avoid the left and right soundstage imbalance caused by the two channels of the reflection of the path of the different.
Of course, every separable desktop stereo comes with speaker cables at the beginning of the purchase. The speaker cables are of equal length, and should not be shortened during installation for fear of trouble, or it will be no different from having two speakers placed far apart and one close together. If your speaker cable is not long enough, or for other reasons need to be purchased separately, then it is recommended that you buy a higher quality hi-fi speaker cable, because of such a small loss of resistance of the speaker cable sound quality is higher, in addition to some of the speaker cable also has the ability to anti-interference. Of course, you need to buy the same length of line.