Originally Posted by kb9wyz
In an XLR cable you have three conductors for Left,Right and Ground.
Sorry, but as a sound engineer, I've got to call you up on that.
XLR stands for Ground (X), Live(L), and Return(R).
When cutting open an XLR you will find lots of copper strands twisted around the inner two cores. this picks up misc signal, ie phone interference etc. it then takes it to the end of the cable, in which it will meet a piece of equipment which is grounded. it then discharges it's signal there, rather than adding it to the music.