Please be aware that most "microphone" cables (i.e. from a "music store") are incorrectly wired -- they often have pin 1 tied to pin 0, which is the shell. As clever as this is for electrocuting musicians, we still have musicians so the premise isn't working well...
Seriously, you'll have to open both ends and determine if the wiring is 1==1, 2==2 and 3==3, with nothing else.
You also might try disconnecting EVERYTHING, then start from the sub and speakers BACKWARD, listening to each step.
And of course IF you have TV cable connected to anything then that's very probably your culprit.
Regards,
Barry
Seriously, you'll have to open both ends and determine if the wiring is 1==1, 2==2 and 3==3, with nothing else.
You also might try disconnecting EVERYTHING, then start from the sub and speakers BACKWARD, listening to each step.
And of course IF you have TV cable connected to anything then that's very probably your culprit.
Regards,
Barry