Hi, I am just inquiring that is it necessary to give a 5.1 input to my MJ 580 speaker system. In order to produce sound from all 6 speakers......as whenever I am switch on the subwoofer and plug the center speaker(rather any speaker) into the center Output...a constant HISSING sound is being produced.......irrespective of I play FM/AUX/USB/SD.....PLEASE guide me......thank u...