How Much Do You Know About Audio Cables?
In the audio equipment, the necessary accessories is the wire, the choice of wire is also very important. If the wire is bad there will be things like signal loss, distortion and so on.
We all know that the signal transmission between the analog and digital devices in the audio equipment system must be interconnected by wire.
Even if there is a good device, without a reasonable mix of audio cables and connectors, it can not play the best effect of its equipment. Therefore how to correctly select the required cable is crucial.
Digital Audio Cables
Commonly used digital audio cables can use the same connectors as analog audio, such as XLR , Lotus port RCA, BNC, etc.. Of course, the use of analog cables to replace the digital cable, can also be transmitted out of the signal, but will affect the quality of transmission.
The output impedance of analog cables and digital devices have relatively strict requirements with the cable impedance. Analog cable regardless of length, at all points of the cable, the impedance is 600Ω, analog equipment in level matching when the input and output impedance less than 600Ω will not affect the sound quality of analog audio.
If used for digital audio equipment is different, digital audio signal is a high operating frequency pulse data stream, in order to accurately transmit the signal, the cable must be matched with the transmitting and receiving equipment, the impedance of the beginning to the end of the cable must maintain a uniform standard.
If the cable of analog equipment instead of digital equipment on the digital cable, the characteristic impedance does not match, because the digital electrical signal frequency is very high, the characteristic impedance match the current in the wire skin-effect will be deeper, the deeper the transmission effect is better.
Mismatched skin-effect will be shallower, the transmission effect will be worse, this is due to the formation of most of the current in the cable reflection, will generate standing waves and consume signal energy, so that the digital pulse signal waveform distortion.
As the cable impedance mismatch cable in the distribution of capacitance, distribution of inductance, resistance can directly affect the frequency response of the signal, affecting the rising and falling edge of the pulse time (that is, in the code element for “1” or “0”, in the beginning and end of each data bit cycle, there is a level jump, mismatch will affect the level of the complete jump), in the transmission of the receiving end, the interpretation of the digital signal will appear false code, if the rising edge of the pulse time and falling edge of the time shift will cause jitter and reduce the quality of audio. If the pulse rising edge time and the falling edge of the time before and after the offset, will cause a long jitter time and reduce the quality of the audio, and even generate noise to degrade the sound quality.
In the recording and production of various types of programs, the need to use audio cables for audio system equipment combinations, in addition to digital mixing consoles, there are many digital and analog peripheral devices such as various types of microphones, equalizers, delayers, effects, synthesizers, D / A converters, audio processors, digital recording and playback equipment, monitoring speakers and other equipment, often think that the connection can be, ignoring the program quality transmission indicators.
If the equipment used technical indicators are not high, the shortcomings of the cable is not yet revealed.
If the equipment indicators in the recording room are entry-level equipment, the application of impedance-matching cables becomes an important part of the audio indicators to meet the standards that cannot be ignored.
This result of the emergence of the transmission cable must be used to match the equipment, with the same time, the equipment input and output levels should also be reasonably matched.
Analog audio cables can be broadly divided into microphone cables, transmission line cables and speaker cables.
Audio cable has a single-core line, two-core line, three-core line.
Core wire is the conductor of the audio signal; conductor outer layer by the braided network and protective layer of the outer skin synthesis of the shield layer of metal wire, external electromagnetic interference shielding, but also can be used as a signal ground, in the outermost layer of the shield is molded into the cover of non-conductive plastic or rubber, the role of the inner conductor shield line resistance to tension, but also to protect the shield from corrosion; the outermost layer of the outer skin can protect the internal layers, so that the cable is durable.
Audio cables also consider the skin-effect, the general use of copper wire surface silver-plated or tinned as a conductor, because it is low cost, good conductivity, easy to use for mobile. Analog audio cable using the typical centralized plug form, speaker cable commonly used in large diameter multi-strand copper stranded wire, sometimes also use banana plugs or other self-locking plug.