Interference vs. NoiseTwo other common problems are interference and noise. If you are getting a constant hum from your AC powered sound system, the cause could be what is known as ground loop. It is caused by improperly grounded components in the sound system. It is characterized by a low itched hum. To get rid of it requires that you carefully make sure all the components of the system are properly grounded. This problem can be avoided by using DC powered system such as a portable car top unit.
Other causes of noise are introduced by using long cable runs between speakers and amplifiers and between microphones and amplifiers. The cables can act as antennas and get local radio stations, CB and other radio frequency (RF) noise. If your system is going to require over 100 ft. of cable, be sure to use balanced cables.
Balanced cables feature three leads. The outer shield is braided wire surrounding the internal wires and forms the ground. There are two wires inside that carry the + and – of the audio signal. The outer wire shields the audio lines from interference originating from the RF sources.
Other Noise Sources
Background Noise - is caused by your microphone picking up the sounds around you. You have the mic set to high or too “hot”. Turn down the mic level so these sources of audio aren’t picked up by the mic.
Wind Noise – The wind is a constant source of irritation for announcers and outdoor presenters. Use a foam windscreen to reduce this problem. It will also reduce popping from having the mouth too close to the microphone. If the wind is still a problem, use a larger wind screen or reduce the mic level slightly. Try to block the wind with your body.
Download the whole Wireless System Setup Guide here.