The audio cable is more complicated than the video cable. In addition to the above three precautions, there is also a balanced and unbalanced connection problem.
Balanced connection
The so-called balanced connection is a connection method that uses two signal lines to transmit a pair of balanced signals. Since the interference on the two signal lines is the same in magnitude and opposite in phase, the interference will be canceled in the end. Due to the low frequency range of audio, it is susceptible to interference in the case of long-distance transmission. Therefore, as an anti-interference connection method, balanced connection is the most common audio connection for professional equipment. There are also two-core shielded cables used as audio cables in the connection lines of household appliances, but what it transmits is the left and right channels, which are two signals, which is not a balanced connection.
Unbalanced connection
Unbalanced connection is a connection method that uses only one signal line to transmit signals. Because this connection is susceptible to interference, it is only generally used in household appliances or in some cases with lower requirements. The specific connection method takes the XLR connector as an example: 1. Balanced connection: 1 pin is connected to the shield, 2 pin is connected to the + terminal (also called the hot end), 3 pin is connected to the-terminal (also called the cold end); 2. Unbalanced connection Method: Pin 1 and Pin 3 are connected to the shield, and Pin 2 is connected to the + terminal (signal terminal). The choice of connection method generally depends on the specific requirements of the device for the interface. If you can use the balanced connection method, use the balanced connection method as much as possible. When making the connection, be sure to read the instructions on the panel first. It is best to read the relevant instructions and Require.
In some occasions, you may also encounter a situation where the device interface at one end is a balanced interface, and the device at the other end is an unbalanced interface. If the requirements are not very strict, you only need to use the balanced connection at the balanced end, and the unbalanced connection at the unbalanced end. Method, pay attention to the corresponding feet. In the case of strict requirements, a conversion circuit must be used to convert balance to unbalance, or unbalance to balance.
