From the essence of the transmission signal, there are two different types of audio signal lines.

The first is called Interconnect Universal, and you can use it to connect multiple devices.

The signal energy transmitted by interconnected general-purpose cables is very weak. These signals do not require too much energy during transmission, and simple cables can be used to transmit signals from the signal source. For example, the process between a CD player and a power amplifier can use an interconnected universal signal line. The device uses very little energy to transmit signals. The internal current of the interconnect general-purpose signal line is extremely weak, generally only a few milliamps.

The second type is called the power amplifier type, and this type of signal line is used to connect the power amplifier.

Power amplifier type signal lines, on the contrary, in the cable to bear a lot of energy signal transmission tasks. Because all the energy transmitted in this type of signal line will eventually reach the speaker. Therefore, it is usually connected between the amplifier and the speaker. The speaker we are talking about here is not a CD player, nor a ten-watt device, but a few hundred or even a kilowatt device for home theater. Because the signal energy it transmits is quite large, the current inside it is also very impressive, which can reach 10 amps or more.