【 Weak current College 】 audio terminology defined---Power By 【 China power house network 】

Impedance: specifically refers to the AC in the resistance, resistance. Impedance is not a single thing, it is a direct current resistance (Resistance), inductance on frequency response characteristics (gankang, InductiveReactance) and capacitor on the frequency of resistance characteristics (capacitance, CapacitiveReactance). However, because normally we talk about how much impedance values, only to ohms, so it is easy to mistake the impedance is simple "direct current resistance".



Coaxial line: coaxial cable with two conductors, among them a living in a central location, the other is to surround the reticular formation of the centre line of the surrounding, center line and mesh wire insulation material segregation between. Due to the center line and reticular layer is coaxial arrangement, so its name.



Fibre: fibre is to transmit light fibers.



Balanced line: all the signal lines require two wires, one out, a progressive, meaning that one is signal output channels, the other is the signal circuit. General signal lines in the two wires into positive and negative, as the line is the output path, negative line is the signal circuit and grounding sharing. There is another kind of signal lines used in balance system, it has three wires inside and external to XLR Terminal. The internal wires, one of which is responsible for delivery are believed to number, another is responsible for the transmission of the signal, another third is responsible for the grounding.



RGB: red-green-blue. This is the "video" red-green-blue, and non-printing, photos, objects of red-green-blue. Also called RGB (Primary), is that all video systems to be able to see the colors are red-green-blue composition.



VGA: IBM in 1987, the computer monitor specifications, its resolution to 640 x 480.



SACD:SuperAudioCD。 Literal Super CD. This is an override of the CD of new music carrier, is also the inventor ofthe original CD SONY and Philips jointly launch of the new format, using DSD recording mode.



DVD-Audio: both audio DVD, is a DVD audio specifications to replace CD with a new audio formats.



CD: Sony and Philips jointly developed a digital music discs, diameter and 12cm 8cm diameter of two specifications that previously were most common, it can provide the high quality of 74 minutes of music.



DVD: a new generation of CD-like appearance, large capacity optical disc, it will be widely used in high-quality audio-visual programmes and as a computer mass storage devices.



D/A converter: digital audio products (such as CD, DVD) to digital audio signal to an analog audio signal of the device. D/A converter can be made independent of machine to match the CD turntable with, often called a decoder.



CD turntable: CD machine mechanical drive components independent of the machine.



Super sampling: the number of times the sampling frequency of CD format standard sampling frequency 44.1kHz, its purpose is to facilitate D/A conversion, digital noise reduction, improved CD machine high frequency phase distortion. Early CD machine use 2 multiplier or 4 times the frequency of sampling, the recent machines have reached 8 x or higher.



HDCD: HighDefinitionCompactDisc (high resolution CD) abbreviation: an improvement in CD-quality coding system, compatible with the traditional CD, but you need a CD with HDCD decoder on replay or add one to improve HDCD decoders.



Bit (bit): binary digital signal is composed of the smallest units, it is always at 0 or 1 in one of two States.



Bit stream: Philips CD of a digital signal to analog music signal technology.



Dolby B, C, S: United States Dolby company developed the series tape noise reduction system that is used to reduce tape recordings produced by "hissing", extended dynamic range. B-type noise reduction system capable of reducing noise, C-10dB to 20dB, S-type you can reach 24dB.



Dolby Surround (DolbySurround): a rear impact channel coding to stereo channel sound. Replay when you need a decoder will surround sound signals from the encoding of the sound.



Dolby directional logic (DolbyPro-Logic): Dolby Surround sound adds a front of the channel so that the movie on the lock to the screen.



Dolby Digital (DolbyDigital): also known as AC-3, Dolby Labs release of the next generation of home theater surround sound system. Its digital sound contains left front, middle, right front, left surround, right surround 5 channel signals, they are independent of the whole band signals. In addition to all the separate hyper-bass sound channel, commonly known as 0.1 channel. All of these channels together is the so-called 5.1 channel.



AV amplifier: specifically designed for home theater use and design of the amplifier, generally equipped with four or more channel numbers as well as surround sound decoding capabilities.



Dolby Digital Amplifier: also known as AC-3 amplifier, with Dolby Digital decodingFeatures of AV amplifier.



Lucasfilm THX: United States company developed a surround sound standards for Dolby Surround directional logic systems have been improved to enable surround sound effects can be further enhanced. THX standards on replay equipment such as audio source, amplifier, speakers and even connect wire has a set of strict and specific requirements, meet this standard and the Lucas certification through the product, before granting THX logo.



THX5.1: Dolby Digital system with THX.



DTS: digital isolation channel home theater surround sound system (Discrete-channelhomecinemadigitalsoundsystem), it also uses the independent 5.1 channel, the effect is achieved or even better than Dolby Digital surround sound system, Dolby Digital surround sound strong competitors.



SRS: United States SRS businesses with two speakers produce surround system.



Divider: speakers within a circuit of the device, which will enter the music signal separation into treble, Alto, bass, and other different parts, and then fed into the high, mid, Bass trumpet session replay.



Dual amplifier partials (Biamping): Speaker of every loudspeaker unit consists of one independent amplifier channel to be driven by a connection. One of the two frequency speaker will need to use two sets of stereo amplifier and two speakers. See "dual-tone".



Dual-tone (Biwiring): with two sets of speaker cables transfer the music signal is high, the bass part of a connection. Double tap the sound you need to use two on Terminal's specially designed speakers.



Bridge: taking two identical stereo after the class to expand machine, expand each of the machines are converted to left and right stereo to mono bridged expand machine.



Amplifier: Preamplifiers and power amplifiers.



Power amplifier: shear says power amplifier for enhanced signal power to drive the speakers sound production of an electronic device. Without signal source selection, volume control, and other ancillary function of the power amplifier is called after the class.



Preamplifier: amplifier before pre amplifier and control parts, for enhanced signal voltage ranges, and provide input signal selection, tone adjustment and volume control. Preamplifier is also referred to the fore.



Merge-amplifier: the preamplifier and power amplifier in two parts in one of the amplifier in the chassis.



Danji: another tube amplifier.



Changtou: it is used to regenerate the black rubber disc Sonic important equipment, the most common is perturbed magnetic changtou and lap changtou.



Coaxial speakers: coaxial speaker is a high-pitchedmonomer in a bass or bass in a single center location, the two monomers are not full-range unit, but each have their own crossover network. It has the advantage that no single placement location time phase, the two monomers Sonic at reach the listener's ears, audiovisual accurately, relaxed.



Horn speaker: is a voice of compressed drive plus a horn's throat, and finally coupled with a clarion call for open, it forms a complete Horn loudspeaker.



Rated power: power amplifier, rated power generally refers to a valid value for continuous output (RMS) power; the speaker, the rated power as a speaker to suffer this value of power without damage, this does not mean that we need such a power amplifier to push farther, speaker of the main difficulty is driven by its sensitivity and impedance characteristics. It does not mean that you cannot mix output power greater than speakers rated power amplifier. As a car, driving 300 km/h speed sports car is not equal to an accident occurs, you can do so quickly. Similarly, if the volume does not blindly, high power amplifier can be equipped with small power speakers.



Peak output power music (PMPO): the music signal moments of peak voltage to calculate output power, its commercial significance greater than the actual function. PMPO power than internationally recognized RMS rated output power (RMS) higher than 3 to 4 times, for example, early portable recorder per channel RMS power only 4, 5 watts, but using numerical marking, PMPO it can grow to about 20W.



Single Zoom: amplifier output stage by a zoom components (or only a symbol but parallel to a group) to complete the signal plus or minus two and a half weeks of amplification. Single-end machine can only adopt amplify a working state.



Push-pull amplification: power amplifier output stage have two "arms," (two sets of amplification components), an "arm" of the current increases, another "arm" of the currentdecrease, the State took turns to convert. On the load, like a "boom" in a "push" in La, arm complete current output tasks. Although r amplifier can push-pull amplification, but more common is to use the push-pull amplification consisting of a class b or b amplifiers.



CPI: also known as A class, the signal of the entire cycle (sine wave of plus or minus two and a half weeks), amplifier power output of any component does not appear on current deadline (i.e. stop output) of a type of amplifier. Class a amplifier work will produce high fever, inefficient, but an inherent advantage is no crossover distortion. Single amplifier is a class a, push-pull amplifier can be r,Or r or a CPI.



CPI: also known as a B class, sinusoidal signal of plus or minus two and a half weeks separately by two push-pull output stage "arm" take turns to enlarge the output of the amplifier, each "arm" of conducting time signal of half a cycle. The advantages of class b amplifier is a high efficiency, the disadvantage is that produces crossover distortion.



A category b: also known as AB class, bound to the category a and category b, push-pull amplification of each "arm" on-time is greater than the signal of a half-cycle is less than one cycle. A CPI zoom solved r amplifier crossover distortion, efficiency and high class a amplifier for a very wide range of applications.



Distortion: device output cannot fully regained its input, produce the waveform distortion or signal components.



Harmonic distortion: less than ideal because the amplifier and the output of the signal in addition to including enlarged input components, added some of the original signal of 2 x, 3 x, 4 x ... Even more high frequency components (harmonic), leaving the output waveform shape. This caused as a result of harmonic distortion is called harmonic distortion.



Crossover distortion: mode b amplifier characteristic a distortion. This distortion is due to the mechanism of signal and negative half week by different sets of devices for Zoom, positive and negative sides of waveform cannot smoothly.



Bass: music nature neutral, that is the antithesis of the sound program itself does not have some features, such as a jar of speech that sound is typical of bass. Bass show replay signals in multiple out (or less) certain components, this is a distortion.



Sound pressure: indicates that the sound intensity of physical quantities.



Sound pressure level: the number of DB sound pressure.



Sensitivity: sensitivity to the amplifier, it generally refers to attain the rated output power or voltage input voltage of the signal, also known as the size of the input sensitivity; sensitivity to sound, the sound is to impose the input power 1W, 1 m in front of the loudspeaker to producing number distant DB sound pressure value.



Level: electronic system for voltage, current, power, physical strength of common names. Level General in decibels (dB) expressed as a unit. That is, the prior determination of a voltage or current number as a reference value (0dB), used to be that of quantity and value of the access log, and then multiplied by 20 decibels as-level (power level changing the value by 10).



Decibel (dB): level and pressure level of the unit.



Damping factor: load impedance and the output impedance of the amplifier. Use the negative feedback of transistor amplifier output impedance is very low, only zero even less a few ohms, damping coefficient may reach tens to several hundreds.



Feedback: also known as ECHO, a part of the output signal or all echo to the amplifier's input to change the circuit magnification technology.



Negative feedback: lead magnification reduce feedback. Negative feedback while make amplification losses, but the ability to effectively expand the frequency response, reduce the distortion, so the application is very extensive.



Positive feedback: make amplification increases feedback. Positive feedback and the role of negative feedback is exactly the opposite, so use caution should be exercised when.



Dynamic range: signal strongest part and the weak parts of level difference between. On the equipment, the dynamic range represents the equipment on the strength of the signal of reconciliation of processing power.



Frequency response: "frequency response, measure a equipment for high, medium, and low representation of the frequency band signal uniform. On equipment frequency response of the request has two parts: one is a wide range of possible, i.e. to be able to replay the lower limit of the frequency is low, as far as possible, high-ceiling; the second is the points in the frequency range of response to smooth, avoid excessive fluctuations.



: Equipment for music in signal followed. Transient response of equipment should be a signal to respond immediately to stop the signal a GA however only, never slow.



Signal to noise ratio (S/N): also known as CyberLink noise ratio, signal and noise of the useful ingredients of the contrast, often represented by DB. Device-to-noise ratio, the greater demonstrate that it produces less noise.



Sine wave: most single frequency components of a signal because the signal waveform is math sine curve. Any complex signal, such as the musical signal, can be viewed by many different frequencies, the size of the sine wave composite.



Wavelength: Sonic in a cycle tour. Wavelength in numerically equal to the speed of sound (344 m/s) divided by the frequency.



Shielding: electronic equipment or wires outside the conduction of the electromagnetic wave overwrites the ease-of-materials to prevent external electromagnetic noise interference on the useful signal technology.


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Impedance matching: a piece of equipment output impedance and the connected load impedance between a relationship should be satisfied in order to avoid access to the load on the equipment itself had a notable impact on the State. The interconnection of electronic equipment, such as signal source attached amplifier, fore even after the class, as long as the input impedance after level is greater than the top level output impedance 5-10 times above, you can view the impedance matching good; for amplifier connection speaker, electron tube machine should use its output nominal impedance equal or close to the speaker, but this is not a transistor amplifier, you can add any impedance speakers.
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Pot machines: new equipment for the use of power before the preheating process, so that the equipment State of the sound into the stable.