Audio basic knowledge dissemination

1.CD
A digital music disc jointly developed by Sony and Philips has two specifications of 12cm diameter and 8cm diameter. The former is the most common. It can provide 74 minutes of high-quality music.
2. CD-ROM
Read-only CD for storing computer data.
3.VCD
The audio-visual disc using MPEG-1 compression coding technology has the same image clarity as VHS video tape.
4. Super VCD
The improved product of VCD adopts MPEG-2 encoding, and the image clarity has been improved.
5.DVD
A new generation of ultra-large-capacity optical disc similar to CD, it will be widely used in high-quality audio and video program recording and as a mass storage device for computers.
6.MD
The mini-recordable music disc developed by Sony has a 3.5-inch floppy disk shape like a computer, but uses an optical signal pickup system, similar to a CD. MD uses efficient compression technology to achieve the same recording time as CD, and the sound quality is close to CD.
7. D / A converter digital audio products (such as CD, DVD) device that converts digital audio signals into analog audio signals. The D / A converter can be made into an independent machine to match the CD turntable, which is often called a decoder.
8. CD turntable is a machine that separates the mechanical transmission part of the CD player.
9. The oversampling sampling frequency is several times the standard sampling frequency of the CD system, 44.1kHz. Its purpose is to facilitate the digital noise filtering after D / A conversion and improve the high frequency phase distortion of the CD player. Early CD players used 2x or 4x sampling, and recent machines have reached 8x or higher.
10.HDCD
Abbreviation of High DefiniTIon Compact Disc (high-resolution CD)-an encoding system that improves the sound quality of CDs, is compatible with traditional CDs, but requires playback on a CD player with HDCD decoding or an external HDCD decoder to get improved effect.
11. bits
The smallest unit of binary digital signal, it always takes one of two states of 0 or 1.
12. Bitstream Philips' technology that converts CD digital signals into analog music signals.
13. Dolby B, C, S
A series of tape noise reduction systems developed by Dolby Corporation of the United States are used to reduce the "hiss" produced by tape recording and expand the dynamic range. Type B noise reduction system can reduce noise by 10dB, type C increases to 20dB, and type S can reach 24dB.
14. Dolby HX Pro
It is not a noise reduction system, but a technology to improve the distortion of high-frequency tape recording, which is also commonly referred to as "upper headroom expansion".
15. Dolby Surround (Dolby Surround)
A sound that encodes the rear effect channel into a stereo channel. During playback, a decoder is needed to separate the surround sound signal from the encoded sound.
16. Dolby Pro Logic
(Dolby Pro-Logic) adds a front center channel to the Dolby surround sound to lock the dialogue in the movie to the screen.
17. Dolby Digital
Also known as AC-3, a new generation of home theater surround sound system released by Dolby Laboratories. Its digital sound contains 5 channels of left-front, center, right-front, left surround, and right surround signals, all of which are independent full-band signals. In addition, there is a separate channel for subwoofer effect, commonly known as 0.1 channel. All these channels together are called 5.1 channels.
18. Amplifiers specifically designed for home theater use by AV power amplifiers generally have more than 4 channels and surround sound decoding.
19. Directional logic surround sound amplifier AV power amplifier with Dolby directional logic decoding function.
20. Dolby Digital Amplifier is also called AC-3 amplifier, an AV power amplifier with Dolby Digital decoding function.
21. The receiver has an amplifier with radio function.
22.THX
A surround sound standard developed by Lucasfilm in the United States. It improves the Dolby directional logic surround system and further enhances the surround sound effect. The THX standard has a set of strict and specific requirements for playback equipment such as audio and video sources, amplifiers, speakers, and even connecting cables. Products that meet this standard and are certified by Lucas are only granted the THX logo.
23.THX 5.1
THX based on Dolby Digital System.
24.DTS
Discrete-channel home cinema digital sound system (Discrete-channel home cinema digital sound system), which also uses an independent 5.1 channel, the effect is even better than Dolby digital surround sound system, is a strong competitor of Dolby digital surround sound .
25. SRS
An American SRS company's system that uses two speakers to produce a surround sound effect.
26. A circuit device in the crossover speaker box to separate the input music signal into different parts such as treble, midrange and bass, and then send them to the corresponding high, middle and woofer units for playback.
27. Biamping (Biamping)
Each speaker unit of the speaker is driven by an independent amplifier channel. A pair of two-way speakers requires two stereo amplifiers and two pairs of speaker cables. See "Double Line Crossover".
28. Biwiring
A wiring method that uses two sets of speaker cables to separately transmit the high and low parts of the music signal. Two-wire crossover requires specially designed speakers with two pairs of terminals.
29. A general term for amplifier preamplifier and power amplifier.
30. Power amplifier is abbreviated as power amplifier, an electronic device used to enhance the signal power to drive the sound of the speaker. Power amplifiers without auxiliary functions such as signal source selection and volume control are called post-stage.
31. The pre-amplification and control part before the preamplifier power amplifier is used to enhance the voltage amplitude of the signal, provide input signal selection, tone adjustment and volume control functions. The preamplifier is also called the pre-stage.
32. See "Power Amplifier" for the next stage.
33. For the front stage, see "Preamplifier".
34. The combined amplifier integrates the pre-amplification and power amplification in one chassis.
35. Another way to say tube amplifier.
36. Rated power For power amplifiers, rated power generally refers to the RMS power that can be continuously output; for speakers, the general term for rated power refers to the speaker can withstand this value of power for a long time without damage, which does not mean Such a high-power amplifier must be needed to push it, and the drive of the speaker is mainly determined by its sensitivity and impedance characteristics. Nor does it mean that a power amplifier with an output power greater than the rated power of the speaker cannot be equipped. Just like driving a car, driving a sports car with a speed of 300 kilometers per hour does not mean that a car accident will occur, you can not drive so fast. Similarly, as long as the volume is not increased blindly, high-power amplifiers can also be equipped with low-power speakers.
37. Peak music output power (PMPO)
The commercial power of the output power calculated by the peak voltage that the music signal can reach in an instant is greater than the actual effect. PMPO power can be 3 to 4 times higher than the internationally recognized effective value rated output power (RMS). For example, the RMS power per channel of early portable recorders is only 4, 5 watts, but it is marked by PMPO. As big as 20W.
38. The output stage of the single-ended amplification power amplifier is completed by one amplifying element (or multiple elements but connected in parallel to a group) to amplify the positive and negative two and a half cycles of the signal. Single-ended amplifiers can only take Class A working conditions.
39. The output stage of the push-pull amplifier has two "arms" (two sets of amplification elements). When the current of one "arm" increases, the current of the other "arm" decreases, and the state of the two switches in turn. To the load, it seems that an "arm" is pushing and an "arm" is pulling together to complete the current output task. Although class A amplifiers can use push-pull amplification, it is more common to use push-pull amplification to form a class B or class A amplifier.
40. The conduction mode of the power amplifier tube in the class power amplifier is divided into class A (class A), class B (class B) and class A and class B (class AB).
41. Class A is also known as Class A. During the entire period of the signal (both positive and negative halves of the sine wave), any power output element of the amplifier will not have a current cutoff (ie, stop output). Class A amplifiers generate high heat during operation, and the efficiency is very low, but the inherent advantage is that there is no crossover distortion. Single-ended amplifiers are all Class A working methods. Push-pull amplifiers can be Class A, B, or A or B.
42. Class B is also known as class B. The positive and negative half cycles of the sinusoidal signal are output by the two "arms" of the push-pull output stage, and the output time of each "arm" is half of the signal. cycle. The advantage of Class B amplifier is high efficiency, the disadvantage is that it will produce crossover distortion.
43. Class A and B, also known as class AB, is between class A and class B. The on-time of each "arm" of the push-pull amplification is greater than half a cycle of the signal and less than one cycle. Class A and Class B amplification effectively solves the crossover distortion problem of Class B amplifiers, and the efficiency is higher than that of Class A amplifiers, so it has been extremely widely used.
44. The output of the distorted device cannot completely reproduce its input, resulting in distortion of the waveform or increase or decrease of the signal components.
45. Harmonic distortion Because the amplifier is not ideal, in addition to the amplified input components, the output signal also adds some 2 times, 3 times, 4 times ... or even higher frequency components of the original signal (harmonics ), Causing the output waveform to alias. This distortion caused by harmonics is called harmonic distortion.
46. ​​Crossover distortion A type of distortion unique to Class B amplifiers. The mechanism of this distortion is that the positive and negative half cycles of the signal are amplified by different sets of devices, and the positive and negative waveforms cannot be smoothly connected.
47. The opposite of the natural neutral of sound-dye music, that is, the sound is dyed with some characteristics that the program itself does not have. For example, the kind of sound obtained by speaking into a jar is a typical sound-dye. The sound stain indicates that some components are added (or reduced) in the reproduced signal, which is obviously a distortion.
48. Sound pressure indicates the physical quantity of sound strength.
49. The sound pressure level is expressed in decibels.
50. Sensitivity For amplifiers, sensitivity generally refers to the magnitude of the voltage applied to the input when the rated output power or voltage is reached, so it is also called input sensitivity; for speakers, sensitivity refers to the application of 1W of input power to the speaker How many decibels of sound pressure can be generated 1 meter away in front of the horn.
51. The general term for the physical strength of voltage, current, power, etc. in level electronic systems. The level is generally expressed in decibels (dB). That is, a voltage or current number is taken as a reference value (0dB) in advance, and the ratio of the amount to be expressed to the reference value is taken as a logarithm, and then multiplied by 20 as the decibel number of the level (the power level value is changed by 10) .
52. Decibels (dB)
Unit of level and sound pressure level.
53. Ratio of damping coefficient load impedance to amplifier output impedance. The output impedance of the transistor amplifier using negative feedback is extremely low, only a few ohms or even smaller, so the damping coefficient can reach tens to hundreds.
54. Feedback is also called feedback, a technique that returns part or all of the output signal to the input of the amplifier to change the circuit magnification.
55. Negative feedback leads to feedback with reduced magnification. Although negative feedback causes loss of amplification, it can effectively widen the frequency response and reduce distortion, so it is widely used.
56. Positive feedback feedback that increases the magnification. The role of positive feedback is just the opposite of negative feedback, so you should be careful when using it.
57. The level difference between the strongest part and the weakest part of the dynamic range signal. For equipment, the dynamic range means that the equipment can handle both strong and weak signals.
58. Frequency response is abbreviated as frequency response, which measures the ability of a piece of equipment to reproduce the signals of high, medium and low frequency bands evenly. There are two requirements for the frequency response of equipment. One is that the range is as wide as possible, that is, the lower limit of the frequency that can be replayed is as low as possible, and the upper limit is as high as possible. Second, the response of each point in the frequency range is as flat as possible to avoid excessive fluctuations.
59. The ability of transient response equipment to follow sudden signals in music. The equipment with good transient response should respond immediately as soon as the signal comes, and stop suddenly when the signal stops.
60. Signal-to-noise ratio (S / N)
Also known as the signal-to-noise ratio, the useful component of the signal is compared with the strength of the noise, often expressed in decibels. The higher the signal-to-noise ratio of the device, the less noise it produces.
61. The signal with the most single sine wave frequency component is named because the waveform of this signal is a mathematical sine curve. Any complex signal, such as a music signal, can be seen as a composite of many sine waves with different frequencies and different sizes.
62. The travel of a wavelength sound wave in one cycle. The wavelength is numerically equal to the speed of sound (344 meters per second) divided by the frequency.
63. The technology of shielding the outside of electronic devices or wires with materials that are easy to conduct electromagnetic waves to prevent external electromagnetic clutter from interfering with useful signals.
64. Impedance matching A certain relationship between the output impedance of a piece of equipment and the load impedance of the connected device, so as not to have a significant impact on the working state of the equipment itself after the load is connected. For the interconnection of electronic equipment, such as a signal source connected to an amplifier and a pre-stage connected to a post-stage, as long as the input impedance of the next stage is greater than 5-10 times the output impedance of the previous stage, the impedance matching can be considered good; for the amplifier connection As far as the speakers are concerned, the electronic tube machine should use speakers whose output terminal has a nominal impedance equal to or close to it, while the transistor amplifier has no such limitation, and can connect speakers of any impedance.
65. The new equipment of the machine uses the preheating process before power-on, so that the sound of the equipment enters a stable state.
66.ADD
Refers to the recording of CD records in analog mode, and editing and mastering in digital mode.
67.AC (AlternaTIng Current)
Alternating current refers to the mains power supply whose current direction changes periodically. Anglo-American uses 60Hz, while China uses 50Hz.
68. Active crossover network (AcTIve Crossover)
Refers to an active electronic network that can group the frequency components of the audio signal (bass, midrange, and treble) before amplification and add them to their respective speaker systems. Although the active crossover network is mostly built into speakers such as subwoofers to drive the subwoofer, in a multi-channel system, the active crossover network can also be used alone.
69.ATRAC
Refers to adaptive transform acoustic coding. It is a low bit rate data compression coding technology adopted by Sony Corporation in its MD magneto-optical disc recorder.
70. Audiophile
Refers to those who have a particular preference for audio technology.
71. Bandwidth (Bandwidth)
Refers to a range of frequencies. For audio recording, bandwidth refers to the frequency response range of band performances or soloists that the sound system or recording device can tolerate; for home sound playback devices, bandwidth refers to system playback The frequency range that can be "listened" is usually in the range of 20Hz or 30Hz to 15kHz or 20kHz.
72. Bipolar Loudspeaker
Refers to a type of speaker device in which the sound-generating unit points to the front and rear of the speaker and feeds signals in phase. Since the pushed signals are in the same phase, the acoustic signal will not be cancelled in reverse phase, and the lateral acoustic radiation will not be attenuated sharply. Bipolar speakers usually need to be placed far away from the front wall, so that the sound waves directed backwards can be properly reflected.
73. Connecting cables (Cables)
Refers to the signal line or the speaker wire, usually the purity of the copper content of the wire is used to indicate the quality of the wire, such as 6N means that the copper content of this wire has reached 99.99997%. Speaker wires with good performance are mostly composed of multi-core wires, and single or a few thick-gauge copper wires are also available. Directional speaker lines are marked with arrows to indicate the wiring direction from the power amplifier to the speaker, and some signal lines are also marked with arrows to indicate the wiring direction from the signal source to the power amplifier.
74.DAB (Digital Audio BroadcasTIng)
Refers to digital audio broadcasting. Both FM and AM broadcasts are digital stereo. The British BBC radio station is being piloted in some areas. In recent years, China has also started pilot broadcasts in Guangdong, Beijing and other places. DAB needs to use a special receiver (radio) to listen.
75.DAC (digital-to-analog converter, also called decoder)
Refers to a digital-to-analog (D / A) converter that converts on / off pulse signals into analog sound signals. The DAC is installed in the CD player, but the external DAC can upgrade the sound quality of the CD player or other digital players.
76.DAT (Digital Audio Tape Drive)
Acronym for Digital Audio Tape. Refers to a digital recording device mainly used for professional recording, using a rotating magnetic head similar to a video recorder (VCR).
77. Data Reduction
A technique that seeks to reduce the amount of data required to store music. Sony Corporation of Japan has adopted ATRAC compression encoding technology in its MD magneto-optical disc recorder, while Philips in the Netherlands has adopted similar PASC (Precision Adaptive Subband Coding) technology in the DCC digital cassette tape drive it developed. Both of these methods use data compression methods to try to remove data that is not audible to those people's ears.
78. DCC (Digital Compact Cassette)
A home-use digital cassette tape recorder developed by Philips in the Netherlands sounds close to a CD player, but it is inconvenient to use. Due to the competition with Sony's MD, it ended in failure and has gradually disappeared from the market.
79.DDD
Refers to the recording, editing and mastering of CD records using digital processing.
80.dB (decibels)
The unit that measures the change in sound pressure can hear the difference when there is a 1dB change, and when there is an increase of + 10dB, the loudness of the sound will double.
81. Digital output (Digital Output)
Refers to the digital signal output that can be stored or processed by an external DAC. It can be an electrical signal output or an optical (optical fiber) output.
82. Dipolar Loudspeaker
The structure is the same as the bipolar speaker, but the front and rear speakers are fed with signals in reverse phase, so the sound radiation pattern is inverted "8" shape. Mostly used as a surround sound box. THX recommends the dipole type for surround speakers.
83. Distortion
Refers to undesired signals or changes made to the signal by the device.
84.DVD
Refers to a video disc used for home entertainment. DVD discs need to be played with a DVD player. The sound image will be displayed on the screen of a large color TV equipped with corresponding hardware or the monitor of a desktop computer equipped with a DVD-ROM.
85. DVD-ROM
Refers to a CD-ROM similar to CD-ROM, but better than CD-ROM, read-only CD-ROM, specifically for computer use, DVD-ROM can have different storage capacity, single-sided single-layer 4.7GB and double-sided 17GB .
86.DVD-Audio
DVD audio records, currently version 1.0, with 24bit / 192kHz as the standard. There are still some other music DVDs made by DVD-Video, but not the same as DVD-Audio.
87.DVD-R
A member of the DVD family is a DVD that can write to and read data many times at once. The DVD-R can be single-layer (3.95GB) or double-layer (7.9GB).
88.DVD-RW
A kind of erasable and rewritable DVD disc with a storage capacity of 3GB, jointly launched by Sony Corporation of Japan, Philips Corporation of the Netherlands and HP Corporation of the United States, is similar to DVD-RAM. At present, a DVD-RW with a capacity of 12GB is being developed to record 5 hours of TV programs.
89.DVD-RAM
A kind of erasable and rewritable DVD discs for computers, the specified storage capacity is 2.6GB (single layer) and 5.2GB (double layer).
90.Divx
A special way of renting DVD discs introduced by Circuit City of the United States. After a one-time payment, you can watch continuously for 48 hours without refund, but you can pay for it if you watch it again.
91. Electrostatic Speaker
Refers to the type of speakers that use the electric force generated by high voltage to push a thin and light diaphragm to make sound.
92. Flutter
Refers to the phenomenon that the recording tape or record has fluctuations in tone due to rapid changes in rotation speed, which are mostly caused by malfunctions.
93. Frequency (Frequency)
Generally speaking, high-frequency sounds are called high-pitched sounds, and low-frequency sounds are called bass sounds. The audible frequency range is between 16Hz and 20kHz.
94. Front End
The signal source in a multi-finger audio system, such as a LP compact turntable or a CD player, sometimes refers to the front stage of the tuner (radio head) that processes the signal received from the wireless.
95. Herz
The unit of frequency, 1 Hz means that the signal has a periodic change every second.
96. Home Theater System
The home theater device is a combination of audio-visual equipment with excellent performance, which is used to create a sound and picture experience at home similar to that when watching performances in movie theaters. Although the picture quality of most film and television equipment, especially televisions, is not yet perfect, but after investing a certain amount of financial resources, they can obtain very good sound effects in audio.
97. MD machine (Minidisc)
A Sony Sony company can record for 74 minutes, the shape is similar to the computer floppy disk, and the size of the 64mm magneto-optical disk drive, MD magneto-optical disks are pre-recorded and recordable.
98. Independent mono power amplifier (monobloc)
Refers to a completely independent mono power amplifier, therefore, two separate power amplifiers are required for a two-channel stereo system. The advantage is that there is no interconnection between channels at all.
99. Moving coil (MC) cartridges This cartridge will move relative to a fixed magnet to produce a signal, but the output is lower than that of a moving magnet (MM) cartridge.
100. Moving magnet (MM) cartridge refers to a small magnet cartridge that moves relative to a fixed coil to generate a signal.
101. Licam (Nicam)
Refers to a TV sound broadcasting program with sound quality equivalent to CD.
102. Ohm
For the unit of measurement of the resistance caused by the current, the impedance value of the speaker is measured in ohms. Generally, the lower the impedance of the speaker, the harder it is to push.
103. Oversampling
For DAC systems, when the sampling frequency is increased, the work of the conversion circuit is easier to carry out, and the auxiliary circuit is also easier to filter out those unwanted signals.
104. Passive
Refers to those circuits or devices that do not amplify the signal and introduce minimal distortion.
105. Phono amplifier
Since the signal level of the LP phono's phono output is lower than the output of CD phono and tape recorders, it is necessary to add a special preamplifier with frequency equalization, that is, a phono amplifier. In the past, many pre-amplifiers or combined power amplifiers were equipped with such amplifiers, but because LP gradually withdrew from the market, there are few such input stages in the current amplifiers.
106. Quantization
Refers to the digital audio signals that are used to represent the various possible values ​​of different amplitude levels.
107. Sampling rate
Refers to how fast the digital recorder or player samples the signal. For example, the sampling rate of CD players, DCC digital recorders, and MD magneto-optical disc drives is selected as 44.1kHz, which is 44100 samples per second, while the sampling rate of DAT digital recorders is Choose 48kHz or 44.1kHz, DAB digital audio broadcasting uses a sampling rate of 32kHz. The sampling rate determines the highest frequency that the digital system can record. Therefore, the method of high sampling rate is currently being studied. For example, Japan Pioneer is developing a system that increases the sampling rate to 96kHz. In addition, DVD-Audio also uses a high sampling rate of 96kHz.
108. Shielding
Refers to some measures taken to isolate wires or equipment from interference.
109. Subwoofer
Refers to special loudspeakers used to replay those deep, low frequency bands that cannot be reproduced by ordinary small speakers.
110. Tonearm
It is a part of a record player with a cartridge.
111. Transient
Refers to the short and explosive sounds in music (especially percussion). Usually, these sounds are difficult to reproduce accurately.
112. Three-line splitting (push) (Triamping / Triwiring)
Refers to a way of connecting a power amplifier and a speaker similar to biwiring and biamping, but in this case, three pairs of speaker cables and / or three power amplifiers are used, and only applicable to three-way frequency And speakers with corresponding input terminals.
113. Shake (Wow)
Refers to the unstable and deformed sound caused by the slow change of the speed of the recorder or the recording base.
114.AAD
It means that both recording and post-production are in analog (A) mode, and only the producers use digital (D) CD records.
115. A / B audition comparison (A / B comparison)
Refers to the repeated audition comparison of two different music playback methods.
116. Absolute polarity
When using a sound system with the correct absolute polarity to play recordings with the correct absolute polarity, the forward sound pressure generated by the speaker will be the same as the positive sound pressure of the original sound. When the absolute polarity is incorrect, there will be a 180 ° phase difference. For some musical instruments, some people can hear the correctness of absolute polarity.
117. Power line purifier (AC line-conditioner)
Refers to a kind of audio auxiliary equipment specially used to filter the noise in the AC power supply and prevent the audio equipment from being damaged by voltage peaks and surges. Some power purifiers can even be used to prevent lightning damage. In fact, the power purifier is a specially designed and manufactured filter.
118. Sound-absorbing material (acoustic absorbed)
Refers to any material that can absorb sound waves, such as carpets, curtains, and furniture covered with thick cloth.
119. Acoustic diffuser
Refers to any material or device that can diffuse sound waves.
120. Acoustic feedback
The sound from the speaker will cause the LP turntable, microphone and other sound pickup equipment to vibrate. This vibration is converted into an electrical signal and reproduced by the speaker again. In this feedback process, the vibration will become stronger and stronger due to its own feedback. The howling of the sound reinforcement equipment in the venue due to excessive volume is this kind of acoustic feedback.
121. Acoustic panel absorber
Refers to a kind of sound absorption equipment that uses the function of a partition to absorb from low frequency to intermediate frequency. When a sound wave hits the sound-absorbing board, the sound-absorbing board will vibrate, thereby transforming the sound energy into a small part of the heat energy of the board.
122. Acoustics
Refers to a science specializing in sound. Also used to refer to the absorption and reflection characteristics of sound in the listening area, such as "the acoustic characteristics of this listening room are good."
123. AC synchronous motor (AC synchronous)
Refers to the type of motor whose speed is determined by the frequency of the AC power applied. Mostly used in belt-driven turntables.
124.AC-3
Dolby Digital (DD) 5.1-channel digital surround sound format was originally called.
125. Active crossover network (active crossover)
Refers to an active electronic circuit that can divide the low-frequency, middle-frequency and high-frequency in the audio signal before amplification and add them to their respective sound-producing units. Although the active crossover network is mostly used in subwoofers, in a multi-channel system, the active crossover network can also be used alone.
126. Active subwoofer (active subwoofer)
Refers to the type of speakers that are specially used to reproduce low frequencies and are driven by a built-in power amplifier.
127.ADD
Refers to CD recording in analog mode (A), while editing and production use digital (D) mode.
128. Analog / Digital Converter (ADC)
A circuit that converts analog signals to digital signals.
129. Adjacent-channel selectivity (adjacent-channel selectivity)
Refers to the ability of the receiving tuner to select the station you want to listen to and suppress interference from nearby stations.
130. Alternate-channel selectivity
Refers to the ability of the receiving tuner to suppress interference from other stations separated from the desired station by two stations.
131. AES / EBU digital interface (AES / EBU interface)
A professional interface for transmitting digital audio signals. The AES / EBU signal line is a balanced transmission line using XLR plugs. In addition, it is also used in certain consumer electronics products. It is named according to American AES (Audio Engineering Association) and EBU (European Broadcasting Union).
132. Aggressive (aggressive)
Acoustic term used to refer to the type of forward-thinking performance that would throw music to the listener.
133. Air sense (air)
Acoustic term used to indicate the openness of treble, or the spatial separation of musical instruments in the sound field. At this time, the high frequency response can be extended to 15kHz-20kHz. Antonyms include "dull" and "thick".
134. Air-bearing tonearm
Refers to the LP turntable's tone arm is a kind of tone arm supported by an air cushion.
135. Air-bearing turntable
A turntable is a type of turntable held up by an air cushion.
136. Surround (ambience)
Also called a sense of envelopment. Refers to the sense of envelopment of a certain scale and space produced by the sound of the movie. Usually created by surround speakers.
137. Ampere
The unit of measurement for current is indicated by A.
138. Analysis (analytical)
The audio equipment can reproduce every detail in the recordings in great detail, but it uses the wrong way. This analysis method is extremely lacking in music.
139. Simulation
Refers to the analog signal voltage change is a simulation of sound waves, that is, the voltage will continue to change with the original acoustic waveform. Contrast with digital signals of audio or video signals represented by 0 and 1 in binary.
140. Image distortion (anamorphic)
Refers to the wide-screen image of a film or video that is "narrowed" horizontally with a lens or digital processing method so that it can adapt to the standard 4: 3 aspect ratio. During playback, the original aspect ratio of the image is restored by "back-pressing". The image distortion format can provide the correct aspect ratio without sacrificing resolution.
141. Silence (anechoic)
It literally means "no echo".
142. anechoic chamber
Refers to a room without reflection. Sound absorbing materials with good sound absorption performance are laid on the walls of the anechoic chamber. Therefore, there is no reflection of sound waves in the room. The anechoic chamber is specially used to test speakers, speaker units, etc.
143. Articulate
Refers to an acoustic term indicating that audio equipment can clearly distinguish between tones.
144. Anti-state adjustment
Refers to the addition of the tonearm to adjust the force applied to the tonearm, thereby counteracting the tendency of the tonearm to naturally slide inside.
145. Aspect ratio
Also known as the aspect ratio, which is the ratio of the width and height of the screen displayed on the screen. The aspect ratio of standard TV is 4: 3 (1.33: 1), while the aspect ratio of wide-screen TV and HDTV is 16: 9 (1.78: 1).
146. ATRAC
Refers to adaptive transform acoustic coding (adaptive transform acoustic coding), which is a low bit rate data compression coding technology used in the MD magneto-optical disk drive introduced by Sony Corporation of Japan.
147. Audiophile
Commonly known as "audio fans" or "audiophiles", it refers to some people who value the sound quality of replayed music very much. .
148. Audiophile nervosa
Refers to those who are constantly tinkering with audio equipment and are not able to enjoy music as much as they are obsessed with audio.
149.A / V
It is the abbreviation of Audio (Audio) and Video (Video), and refers to those audio-visual products with both audio-visual characteristics.
150. A / V input (A / V input)
Refers to the input of an A / V power amplifier receiver or A / V preamplifier that has both audio and video sockets.
151. A / V loop (A / V loop)
Refers to those A / V input and A / V output pairs installed on the A / V power amplifier receiver and A / V preamplifier used. It is used to connect with A / V equipment that can record and play audio and video signals. of. For example, a VCR can be connected to the A / V loop of an A / V amplifier receiver or A / V preamplifier.
152. A / V preamplifier
Also called "A / V controller", it is a kind of audio equipment used to control the volume, select the program source and complete the surround sound decoding power amplifier.
153. A / V preamplifier / turner
Refers to an A / V preamplifier with an AM (Amplitude Modulation) or FM (Frequency Modulation) receiving tuner in the same chassis.
154. A / V power amplifier receiver (A / V receiver)
For the heart of the home theater system. Responsible for receiving signals from program sources, selecting signals to watch and listen to, controlling playback volume, completing surround sound decoding, listening to radio programs, and amplifying the selected signals so as to promote the complete set of speakers in home theaters . Also called "Surround Sound Receiver".
155. Azimuth (azimuth)
In the tape recorder, it refers to the angle between the recording and playback head and the direction of travel of the tape. Ideally, it should be 90 °; in the LP turntable, the angle between the pointer arm and the surface of the record.
156. Baffle
Refers to the front panel of the speaker with some pronunciation units on the top.
157. Balance
Refers to the objective relationship that exists in the relative loudness between the high and low sections of the audio spectrum; also refers to the same (balanced) signal between the left and right channels of the two-channel stereo.
158. Balanced connection
Refers to a connection between audio equipment. There are 3 wires in a single cable, one is used to transmit audio signals, the other is used to transmit audio signals of opposite polarities, and the other is a ground wire.
159. Banana jack
Refers to a small round socket installed on the speaker and power amplifier for connecting with the banana plug of the speaker cable.
160. Banana plug
A plug that is commonly installed at both ends of the speaker cable for insertion into a banana socket.
161. Bandwidth (band width)
Refers to a range of frequencies that an audio device can handle or pass through. For example, the bandwidth of the surround channel of Dolby Surround is 100Hz-7kHz. The surround channel only passes frequencies between 100Hz (bass) and 7kHz (low range of treble). The frequency range that human ear can hear is 20Hz-20kHz. When it comes to the bandwidth of electrical or acoustic equipment, it often refers to the frequency range between -3dB.
162. Bass
Refers to the sound in the lower part of the audio, usually less than 500Hz (otherwise refers to less than 160Hz).
163. Low frequency extension (bass extension)
Refers to the lowest frequency that audio equipment can reproduce. It is a scale used to determine the degree to which the sound system or speakers can dive when playing back bass. For example, the low frequency of small subwoofers can be extended to 40Hz, while large subwoofers dive to 16Hz.
164. Bass management
Refers to the integrated control circuit in the A / V power amplifier receiver or A / V preamplifier, which is used to determine how much low frequency signals should be sent to the corresponding speakers.
165. Inverted speaker (bass reflex)
It is also called inverted type open-hole box. It is a type of speaker with inverted holes (slots) on the speaker panel. Due to the opening, the sound in the box can be radiated to the outside. Inverted speakers have better low-frequency extension than enclosed speakers, but bass is often less compact. Compare "infinite baffle"
166. Bi-amping promotion (bi-amping)
Refers to a special connection method that uses two power amplifiers to drive the same speaker. One power amplifier is used to drive the bass unit; the other uses a power amplifier to drive the midrange and tweeter.
167. Big screen
Refers to the large screen in an intuitive color TV or rear projection TV. Usually, the diagonal size of the screen is mostly more than 40 inches.
168. Special stereo recording (binaural recording)
Refers to a special recording method intended to install a recording microphone in the ear channel of the simulated human head. Due to the physical structure of the simulated human head, some special spatial information will be included in the recording. When using headphones to listen to such recordings, it will produce a wonderful three-dimensional space that is different from the real situation.
169. Binding post
Refers to the terminal block installed on the power amplifier and the speaker for connecting with the speaker cable.
170. Bipolar speaker
A type of speakers that radiate sound waves simultaneously, both forward and backward. Unlike dipole speakers, bipolar speakers radiate forward and backward sound waves in phase.
171. Bipolar transistor
Refers to a transistor that is very commonly used in audio circuits. Bipolar stems from the relationship between the current flowing through two semiconductor materials. Bipolar transistors can be divided into NPN type or PNP type according to the polarity of the operating voltage.
172. Bit
The basic unit of binary digits. It usually takes one of two states, 0 or 1. The more bits there are, the more accurate the analog signal will be, and the better the audio signal will be restored.
173. Bit rate (bit rate)
Refers to the number of bits stored or transmitted per second for digital audio or digital video signals. For example, the bit rate of each channel of a CD is 705600 kbs, while the bit rate of 5.1 channels of Dolby Digital (DD) is 384 kbs. A higher bit rate often means better sound quality.
174. Bi-wiring
Refers to a wiring method that uses two sets of speaker cables to connect each speaker. Use one set (one pair) of speaker cables to connect to the input of the woofer in the speaker; and another set of speaker cables to connect to the tweeter of the speaker. Only those speakers specially equipped with two pairs of input terminals can be connected by two-wire crossover.
175. Hair floating (blanketed)
Refers to the lack of high-pitched sound, which seems to suspend sound in front of the speaker and absorb sound.
176. Black level (baack level)
Refers to the video signal level of a row of bright output on a display device after a certain calibration.
177. Weakness (bleached)
Acoustic term used to express the acoustic characteristics of those types of audio equipment that pay special attention to the higher harmonics of instrumental music but not the lower harmonics and the fundamental frequency. The pale voice sounds too bright, thin and lacks warmth.
178. Air sense (bloom)
Acoustic term used to indicate that there is air surrounding the sound image of the instrument.
179. Blooming (bloomy)
It means that the bass around 125Hz is too heavy, especially in a fairly wide frequency range. It is caused by insufficient damping of low frequency or low frequency resonance.
180. Counterfeit goods (boutique brand)
Refers to the seemingly high-end audio, but in fact it is just a fake product that has nothing to do with its inferior components in the chassis.
181. Rendering (bloated)
It means that the mid-bass of 250Hz is too strong. Not enough for low frequency and low frequency resonance damping. See "tubby".
182. Blurred
Refers to poor transient response, blurred stereo image, and poor cohesion.
183. Muffled sound (boxy)
It means that the music I heard sounded like it came from a closed box and resonated somewhat.有时则指在250-500Hz一段有些过强。
184.煲机（break-in）
指新买回的音响器材得通电一段时间后才会让重放的音质变好。
185.桥接（bridging）
指为增加输出功率而将功率放大器和音箱作一种特别的连接。桥接便是将双声道的立体声放大器改接为单路的功率放大器。由其中一路放大器去负责放大波形的正半周，而由另一路去放大波形的负半周，音箱则像两路放大器通道之间的“桥”。桥接时需要用二台同样的双声道立体声放大器。
186.明亮（bright）
指突出4kHz-8kHz的高频段，此时谐波相对强于基波。 Brightness itself is not a problem. The live concerts all have bright sounds. The problem is that the brightness is well-controlled. Too bright (even howling) is annoying.
187.辉度（brightness）
对于视频则专指视频显示器画面上所产生的光量。
188.辉亮信号（brightness signal）
用"Y"表示，视频信号的辉亮信号包含所有的显示信息，彩色视频信号则为亮度和色度信号的综合。
189.尖剌（brittle）
用于表示使得乐器的音色听来刺耳的中频或高频的声特性的声学术语。
190.缓冲（buffer）
指用于将音响或电路级加以隔开的电路。前置放大器便是音源和功率放大器之间的缓冲，因为前置放大器为音源减轻了推动功率放大器的负担。
191.直通试听法（bypass test）
为一种对音响器材进行试听的方法。此时将被测试的音响器材或是接入或是不接入信号的行程中，从而可对其声特性作出评判。
192.校正（calibration）
指为使音响或A/V影视器材的工作能够正常而进行的精确调整。在音响系统中，校正包括调定各个声道的电平；而在视频装置中，校正便是调好色彩、亮度、色度、对比度及其它参数。
193.针臂（cantilever）
指由LP电唱盘的唱头端伸出并在其上边装有唱针的细管。
194.容抗（capacitive reactance）
指电容器所呈现的阻止低频通过但却让高频得以通过的一种特性。容抗使电容器成为一种和频率有依从关系的阻抗。正是利用电容器的容抗才将电容器接在高音单元上，让高音通过而不让低音通过。
195.电容器（capacitor）
一种存贮电荷的电子元器件。在功率放大器中的存贮电容器系用于存贮能量；而在直流供电电源中的滤波电容器，则是用来滤去交流成分的；在放大器电路中的耦合电容器则是用来通过交流的音频信号和隔断直流的。
196.俘获比（capture ratio）
为接收调谐器的技术指标。指在调谐器锁定一个信号较强的电台而抑止一个信号弱些的电台之前，所需的两个电台信号强度之差的z贝值。俘获比越低，调谐器的性能便越好。
197.唱头消磁器（cartridge demagnetizer）
指专门用于消除唱头内的金属部分的杂散磁场的一种器材。
198.CAV LD激光影碟（CAV laserdisc）
指按恒角速度（CAV）录制的LD影碟。不论激光拾取器在什么位置上读取信号，影碟将始终以恒速旋转。也称为“标准格式”的LD影碟。其每面可以录30分钟的节目。参看“恒线速” （CLV）。
199.CD激光唱片（compact disc）
指由日本索尼公司和荷兰飞利浦公司联合研制成的一种直径12cm（个别为8cm）可录74分钟音乐的光盘。
200.CD-R可录光盘（CD Recordable）
指可以录入数字音频的光盘。CD-R为一次录入的光盘。录入后便无法抹掉。
201.CD-ROM只读型光盘指用于存储计算机数据的一种只读型光盘。
202.CD-RW可录可抹光盘（CD-Rewritable）
一种可录入可抹掉而反复重录的CD光盘。但现有大多数的CD唱机却是无法用于播放CD-RW光盘的。
203.中心通道（center channel）
在多声道的音响系统中，摆放在观看室的中间，并位于左右前置音箱当中的中置音箱便是用于重放中心通道中的信息的。在中心通道中几乎皆为影片中的对白。
204.中心通道模式（center-channel mode）
指A/V功放接收机和A/V前置放大器的中心通道的工作设置方式。
205.中置音箱（center-channel speaker）
指家庭影院系统中装于视频监视器的顶部，下面或后面的一种音箱。是用于重放中心通道送来的人声对白之类信息以及其它同荧屏上的动作有关的一些声音。
206.消费电子产品大展（CES）
指每年一度于年初在美国拉斯维加斯举办的国际消费电子产品大展。
207.通道平衡（channel balance）
指音响系统中或个别音响器材中左和右声道的相对电平或音量。也用于表示杜比编码信号中左和右信号的相对差值。为了获得最好的杜比解码效果，有些A/V功放接收机和A/V前置放大器还可以对通道平衡进行调整。
208.通道隔离（channel separation）
系用于衡量一个声道跟其它声道之间的隔离程度的尺度。在家庭影院系统中，当通道隔离不够时，一个声道中的声音便会“串入”另一个声道。比较典型的例子便是杜比环绕声中，前置主声道中的声音会“串入”环绕声道。声道隔离好时，声像定位便会更为准确。
209.胸音（chesty）
指音箱的一种声染色，就像歌唱家因胸腔过大而放声洪量的那种声音。系由于在125~250Hz一段的低频响应上有凸起所引起的。
210.色度（chrominance或chroma）
指视频信号的彩色部分。色度信号中包含有色彩和色调信息，但却没有亮度信息。
211.噗嗤声（chufing）
指倒相式音箱在以高电平重放低音时所发出的那种噗嗤声。原因是此时有大量的空气在音箱开孔处通过。
212.甲类放大（class-A）
也称A类放大。 It is a working state of the amplifier. At this time, the transistor or tube amplifier will amplify the entire audio signal.
213.乙类放大（class-B）
也称B类放大。 It is a working state of the amplifier. At this time, one transistor or tube amplifier will amplify the positive half of the audio signal, while the other transistor or tube amplifier will amplify the negative half of the signal.
214.甲乙类放大（class AB）
也称为AB类放大。 A working state of the amplifier. At this time, the output stage of the amplifier will be in Class A amplification when the output power is low, and will be converted to Class B amplification when the output power is high.
215.丁类放大（class D）
也称D类放大或数字式放大器。 It uses very high frequency transfer switch circuit to amplify the audio signal.具有效率高，体积小的优点。许多功率高达1000W的这类数字式放大器，体积只不过像盒VHS录像带那么大。这类放大器不适宜于用作宽频带的放大器，但在有源超低音音箱中却有较多的应用。
216.限幅（clipping）
当要求放大器输出超过其所允许的输出功率时，便会使输出的音频波形的顶部和底部变得平坦。就像将峰值给削平了似的。限幅会引入大量的失真。让人在音乐的峰值时听到有嘎吱嘎吱的响声。
217.封闭（close-in）
指声音的不够开阔，不大柔和和缺少空气感及细节。多因在频率高于10kHz时有了衰减的缘故。
218.CLV LD激光影碟（CLV laserdisc）
指按恒定线速度录制的LD激光影碟。取决于激光拾取器在碟片上的读取位置，LD碟片的转速将会改变。当激光拾取器在碟片外沿读取时，LD影碟的转速相当对较慢；当拾取器沿碟片内径读取时，转速便会加快。因之，从激光拾取器看来，线速度系保持不变的。也称为“延长播放”影碟，因为碟片的单面便可存贮1个小时的视频节目。
219.同轴电缆（coaxial Cable）
指一种内部的导体被隔离层的编织体所包围的一种电缆。
220.同轴数字输出（coaxial digital output）
指在CD机、DVD机等数字录音源设备上安装的用于输出数字音频的RCA插座。可以用同轴数字信号线来跟其它音响器材连接。
221.同轴发音单元（coaxial driver）
指将一个发音单元（通常为高音单元）装在另一发音单元（通常为中音单元）内部的那类扬声器。
222.编码正交频分复用（COFDM）
原文为coded orthogonal frequency division multiplex，系一种信道编码和调制的方法。在欧洲，主要用于DTV数字电视和DAB数字音频广播。用于将相邻的每部分信号尽可能的分离开来，并分别在可多达1536个离散的频率上传送，因而可减少传输差错和多径传波之类干扰。
223.相参性（coherence）
指对音乐能够有一总体感觉而不是由许多单独部分所组成的那种感受。
224.声染色（coloration）
指在音响系统中，由某一音响器材所引起的声音的改变。有声染色的音箱便不能精确地重放出加给音箱的声信号。比如，有声染色的音箱可能会重放出过多的低音，而在高音方面则有所欠缺。
225.梳状滤波（comb filtering）
指在频率响应上出现的一系列相间的深深的峰值和谷值的现象。通常，当直达声和经听音室内音箱两侧的侧墙所反射而稍许有些延迟的反射声合加在一起时，便会产生这种梳状滤波。
226.共模抑止（common-mode rejection）
当将平衡信号加到差分放大器时，便只将平衡信号之间的相位差给放大了。任何两个相位共同的噪声（共模噪声）皆被差分放大器所抑止。
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