YDIT details how audio signals are transmitted

Source:YDIT 誉德 Release time:2019/9/22 7:11:18 Views:1442

 

(Paperless conference system, ultra-thin integrated lifter) The transmission mode of audio signals is divided into two modes: balanced transmission and unbalanced transmission. Balanced and unbalanced are two different types of audio signal transmission.
First, balanced transmission
There are three cores in the balanced transmission line, one of which transmits a positive half-wave (+) signal, and one half of the transmitted half-wave (-) signal, and the last core is the ground. Generally, the noise that is strung into the cable or equipment will appear at both the positive and negative ends. The voltage and phase to ground are exactly the same. Such noise is called common mode noise. Balanced transmission can transmit common mode noise due to the difference in signal transmission between the two ends of the waveform (that is, the difference in voltage). Therefore, balanced transmission has unmatched anti-interference performance in an unbalanced manner.
Balanced transmission is a very widely used method of audio signal transmission. It uses the principle of phase cancellation to minimize other interference during audio signal transmission. It requires three wires in parallel, namely ground, hot, and cold. Therefore, the balanced input and output plug-ins must have 3 pins, such as a card or a big three-core plug-in. Of course, the transmission cable is also the signal line of the 2-core 1 shield layer. Since the hot-end signal line and the cold-end signal line are relatively close in the same shielding layer, other interference signals received during transmission are also almost the same. The connection principle is that the phase of the hot end signal and the cold end signal are opposite. Therefore, the hot end signal and the cold end signal are subtracted at the input end of the next level device, the same interference signal is cancelled, and the transmitted signal is not lost due to the opposite phase. Balanced transmission methods are often used in professional situations and when the transmission distance is relatively long.
Balanced transmission is part of the perfect sound quality, and the back-end circuitry also requires a balanced circuit design to perfectly match balanced transmission, both of which are indispensable. A true balanced circuit design is to amplify the positive and negative half waves of a waveform with a set of lines and then couple them into a complete waveform. Therefore, each channel requires two sets of fully symmetrical components. In the connection line of the household appliance, the two-core shielded cable is also used as the audio connection line, but it transmits the left and right channels, which are two signals, and are not balanced.
Second, unbalanced transmission (paperless conference system, ultra-thin integrated lift)
Unbalanced transmission is a connection method that uses only one signal line to transmit signals. It has only two terminals: the signal terminal and the ground terminal. Unbalanced I/O ports typically use two-pin, two-pin connector that is typically used in applications where low or near-range signal transmission is required, such as home audio systems. This connection is also commonly used in electronic musical instruments such as electric guitars.
Generally, depending on the specific requirements of equipment docking, you can use the balanced connection method as much as possible. When connecting, be sure to read the instructions on the panel first. It is best to read the relevant items in the instruction manual. In some cases, it may be the case that the device interface at one end is a balanced interface, and the device at the other end is an unbalanced interface. In the case of strict requirements, it is necessary to use a conversion circuit to turn the balance into an imbalance or to turn the imbalance into a balance. (Paperless conference system, ultra-thin one lift)