Home > News > Audio Basics
Nov.2023 22
Audio Basics


Refers to the lack of treble, especially in front of the speakers hanging a blanket or other sound-absorbing materials and the sound to be sucked into the void.


Black level

Refers to a certain calibration of the display device, there is no line of light output video signal level.



Acoustic term used to indicate that those who pay special attention to the instrumental high harmonics and pay little attention to the low harmonics and fundamental frequency of the type of sound equipment sound characteristics. Pale sound will sound too bright, thin and lack of warmth.



An acoustic term used to indicate that there is air surrounding the sound image of an instrument.



Refers to excessive bass at around 125Hz, especially over a wide frequency range. It is caused by insufficient damping of low frequencies or low-frequency resonances.


Boutique brand

Refers to those on the surface seems to be high-end audio, but in fact it is only a false appearance and chassis are loaded with poor quality components of shoddy products.



It means that the bass midrange is too strong at 250Hz. Insufficient damping of low frequencies and low frequency resonances. See "tubby".



Poor transient response, blurred stereo image, poor cohesion.



Refers to music that sounds like it's coming from a closed box with some resonance. Sometimes it refers to the 250-500Hz section is a little too strong.


Boiler (break-in)

 Refers to the newly purchased audio equipment must be powered on for a period of time before the sound quality of playback becomes better.



Refers to the power amplifier and speakers to increase the output power to make a special connection. Bridging is to connect a two-channel stereo amplifier to a single power amplifier. One amplifier is responsible for amplifying the positive half of the waveform, while the other amplifies the negative half of the waveform, and the speaker acts as a "bridge" between the two amplifier channels. The bridge requires two identical two-channel stereo amplifiers.



This refers to the highlighting of the high frequency band from 4kHz to 8kHz, when harmonics are relatively stronger than the fundamental. Brightness itself is not a problem, live concerts have a bright sound, the problem is that the brightness must be well controlled, too bright (or even whistling) will be annoying.



For video, this refers to the amount of light produced on the screen of a video monitor.


Brightness Signal

Expressed as "Y", the brightness signal of a video signal contains all the display information, while a color video signal is a combination of luminance and chrominance signals.



Acoustic term used to denote the mid-range or high-frequency acoustic characteristics that make a musical instrument's timbre sound harsh.



Refers to the circuitry used to separate audio or circuit stages. A preamplifier is a buffer between the source and the power amplifier, because the preamplifier relieves the source of the burden of driving the power amplifier.


Bypass test method (bypass test)

A method of auditioning audio equipment. At this time, the audio equipment to be tested either access or not access to the signal in the trip, so that the sound characteristics can be judged.



Refers to the audio or A/V movie and television equipment in order to make the work can be normal and precise adjustment. In the audio system, calibration includes adjusting the level of each channel; and in the video device, calibration is to adjust the color, brightness, chromaticity, contrast and other parameters.



Refers to the LP turntable by the end of the phonostage and the upper side of the tube equipped with a needle.


Capacitive reactance

Refers to the characteristic of a capacitor that prevents the passage of low frequencies but allows the passage of high frequencies. Capacitive reactance makes a capacitor a frequency-dependent impedance. It is the capacitive reactance of the capacitor that is utilized to connect the capacitor to the tweeter, allowing the treble to pass through but not the bass.



An electronic component that stores an electrical charge. In the power amplifier storage capacitor is used to store energy; and in the DC power supply filter capacitor, is used to filter out the AC component; in the amplifier circuit coupling capacitor is used to pass the AC audio signal and isolate the DC.


Capture ratio

Receive the technical indicators of the tuner. Refers to a stronger signal in the tuner to lock a radio station and suppress a weaker signal before the radio station, the decibel value of the difference between the signal strength of the two radio stations required. The lower the capture ratio, the better the performance of the tuner.


Cartridge Demagnetizer

A device designed to eliminate stray magnetic fields in the metal part of the phono cartridge.


CAV LD laserdisc

Refers to the constant angular velocity (CAV) recording LD disk. The disc will always rotate at a constant speed regardless of the position at which the laser pickup reads the signal. Also known as "standard format" LD disks. It can record 30 minutes of program per side. See "Constant Line Velocity" (CLV).


CD laser disc (compact disc)

A compact disc with a diameter of 12 cm (individually 8 cm) that can record up to 74 minutes of music, jointly developed by Sony Corporation of Japan and Philips Corporation of the Netherlands.


CD-R (CD Recordable)

A CD-R is a compact disc that can record digital audio. CD-R is a one-time recording disc and cannot be erased after recording.



Refers to a read-only optical disk used to store computer data.


CD-RW (CD-Rewritable)

A CD-RW that can be erased and re-recorded over and over again. But most of the existing CD player is not available to play CD-RW discs.



Center channel

In a multi-channel sound system, placed in the middle of the viewing room, and is located in the left and right front speakers in the center speaker is used to play back the information in the center channel. The center channel contains almost all of the film's dialogue.


Center channel mode

This refers to the way the center channel of the A/V amplifier receiver and A/V preamplifier is set up.


Center speaker (center-channel speaker)

Refers to the home theater system mounted on top of the video monitor, below or behind a speaker. It is used to play back information such as vocal dialog sent from the center channel, as well as other sounds related to the action on the screen.


Consumer Electronics Show (CES)

Refers to once a year at the beginning of the year in the United States held in Las Vegas, the international consumer electronics products exhibition.


Channel balance

Refers to the relative levels or volumes of the left and right channels in an audio system or individual audio equipment. Also used to indicate the relative difference between the left and right signals in a Dolby-coded signal. In order to obtain the best Dolby decoding results, some A/V amplifier receivers and A/V preamplifiers can also be adjusted for channel balance.


Channel Separation

Is used to measure the degree of isolation between a channel and other channels. In a home theater system, when channel separation is inadequate, sound from one channel will "bleed" into another. A typical example of this is Dolby Surround, where the sound from the front main channels "crosstalks" into the surround channels. When the channels are well isolated, the image is more accurately localized.



A sound coloring of the speakers, like the sound of a singer's chest that is too large for his or her voice. It is caused by a bump in the low-frequency response at 125~250Hz.


Chrominance (chrominance or chroma)

Refers to the colored portion of a video signal. The chrominance signal contains color and hue information, but no luminance information.



Refers to the chuffing sound made by inverted speakers when bass is played back at a high level. The reason is that a large amount of air passes through the speaker opening.


Class-A Amplification

Also known as class-A amplification. A state of operation for an amplifier. At this time the transistor or tube amplifier will amplify the entire audio signal.


Class B amplification (class-B)

Also called class-B amplification. This is an operational state of the amplifier. In this case, 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.


Class A and B Amplification (class AB)

Also known as class AB amplification. An operating state of an amplifier. The output stage of the amplifier operates as class A amplification when the output power is low, and switches to class B amplification when the output power is high.


Class D amplification (class D)

Also known as Class D amplifier or digital amplifier. Department of the use of very high frequency switching circuit to amplify audio signals. It has the advantages of high efficiency and small size. Many of these digital amplifiers with a power of up to 1,000W are only as large as a VHS video cassette. This type of amplifier is not suitable for use as a broadband amplifier, but in the active subwoofer has more applications.



When an amplifier is asked to output more power than it is allowed to, it flattens the top and bottom of the output audio waveform. It is as if the peaks have been clipped. Limiting introduces a lot of distortion. It makes a crunching sound heard at the peaks of the music.



Refers to the sound is not open enough, not very soft and lack of air and detail. Mostly due to attenuation at frequencies above 10kHz.


CLV LD laserdisc (CLV laserdisc)


Refers to an LD laserdisc recorded at a constant line speed. Depending on where the laser pickup is reading on the disk, the speed of the LD disk will change. When the laser pickup is reading at the outer edge of the disc, the speed of the LDdisc is relatively slow; when the pickup is reading along the inner diameter of the disc, the speed increases. Therefore, from the laser pickup, the line speed is constant. Also known as "extended play" video discs, because one side of the disc can store up to one hour of video programming.


Coaxial Cable

A cable in which the inner conductor is surrounded by a braid with a separating layer.


Coaxial digital output

Refers to the RCA sockets installed on digital recording source equipment such as CD players, DVD players, etc. for outputting digital audio. Coaxial digital signal cable can be used to connect with other audio equipment.


Coaxial driver

Refers to a pronunciation unit (usually tweeter) installed in another pronunciation unit (usually the midrange unit) inside the type of speaker.


Coded Orthogonal Frequency Division Multiplexing (COFDM)

Originally coded orthogonal frequency division multiplex, a method of channel coding and modulation. In Europe, it is mainly used for DTV digital television and DAB digital audio broadcasting. It is used to separate adjacent signals as much as possible and transmit them on up to 1536 discrete frequencies, thus reducing transmission errors and interference such as multipath propagation.



Refers to the music can have a general feeling rather than by many individual parts of the composition of the kind of feeling.


Sound coloration (coloration)

Refers to the sound system, by a sound equipment caused by the sound of the change. Sound coloration of the speaker will not be able to accurately replay the sound signal added to the speaker. For example, acoustically colored speakers may play back too much bass and not enough treble.


Comb Filtering

Refers to the phenomenon of a series of deeply spaced peaks and valleys in the frequency response. Usually, when the direct sound and by the listening room speakers on both sides of the side walls of the reflection and a little delayed reflection of the sound together, will produce this comb filtering.


Common-mode rejection

When a balanced signal is added to a differential amplifier, only the phase difference between the balanced signals is amplified. Any noise that is common to both phases (common-mode noise) is suppressed by the differential amplifier.