At my gym we have a sound system and corded handheld mic, wireless mic, CD player and cassette player hooked up. The problem is an annoying feedback/ humming tone coming through the speakers even with all music and mics turned down. Any clues???
yes, it probably is a grounding issue, although the problem is probably from the amp, not the cables from the tape/cd player/mics. does the amplifier unit have a 3 prong plug, or two prong? if it has three, make sure it is being plugged into a grounded outlet. if it only has two, then there is probably a grounding screw on the back somewhere that you will need to connect a wire to and have grounded.