Microphone mainly has two types: balanced type (two-corewrapping shield) and non-balanced type (one-core wrappingshield). The former one is used in long distance transmission; thelatter is used in short distance transmission around 5 to 10 meters.In general, microphone cable can transmit audio over 100 meters.As the energy provider, microphone 's working voltage is weak because its input signal is 0.001v while the impedance is around 600 ohm. So there are two ways to avoid audio interferenceproblems: pair twist and shield
簡體中文 
English