- 14 Nov 2008
........, the top left pin is for the ground, the top right pin is for the positive polarity, and the bottom pin is for the return, or inverted, polarity.
XLR cables are balanced, because the cables have a ground line and the other two wires carry inverted signals. This makes then very resistant to electromagnetic interference, meaning they can be used in very long runs for professional audio applications, such as setting up a PA system with a mixing console.
Read more: How Does an XLR Cable Work? | eHow.com How Does an XLR Cable Work? | eHow.com