Audio cables may not be the most exciting thing in your device, but if you understand how they work and know how to shop, you can avoid a lot of trouble and get the best sound. This guide will allow you to speed up the wiring of the audio cable input and output, so that you can buy the ideal audio cable. Unbalanced line VS Balanced line Unbalanced line The unbalanced line has two wires: the hot end has a signal, and a common ground wire connects to the insulation coating. Grounded shields can isolate the hot end from signals that cause noise or other noise. Instrument lines are generally unbalanced, as are many patch cables. Since long unbalanced lines are more prone to noise problems, they should not exceed 25 feet in length. Balanced line The balance line audio cable adds a second signal line on the basis of the unbalanced line, called the cold end or the negative end. Both wires transmit the same signal, but the two signals have a phase difference of 180°. When the voltage of the hot-side signal increases, the cold-side signal looks like the hot-side mirror and the voltage drops. The phase of any noise in these two lines is the same, and after a process called "common mode rejection", the noise in these two lines will cancel out. Balanced lines usually have XLR and TRS connectors, which we will mention below. In a few cases, balanced and unbalanced lines can be used interchangeably. Devices usually indicate the type of line used. For example, microphones generally require a balanced line, as is the D.I. box, which can be connected directly to a musical instrument or other line level level device to a mixing console or recording device. Balance lines guarantee freedom from noise when you need longer audio cables.