The Cannon Connector

Yesterday we went over the simple RCA single ended cable construction. Today we see what's inside a balanced XLR cable. The simplest description of a balanced cable is two single ended conductors in a shielded enclosure. A single ended RCA cable is one conductor in a shielded enclosure, the balanced XLR has two conductors. Otherwise, the two cables are built the same way. One obvious difference between the two cables is the connector, which allows for the three wires in the balanced cable to be connected, vs. the two in an RCA. The balanced connector is referred to as XLR. The term XLR is commonly used, but years ago we used to call it something different. It was known to many of us as the "Cannon" connector. It was invented by James Cannon, used primarily in commercial installations, rarely in home audio applications. When it was first introduced the official name was the Cannon X connector. Later a locking mechanism was added, those models receiving the designation "L", the part then known as the XL model. When the female end of the Cannon Connector had a rubber insulator added, the final designator "R" was added and we got "XLR". But to many of us, it's still a Cannon Connector. So, a balanced cable has three wires inside: ground, conductor 1, conductor 2. A single ended cable has only two wires: ground and conductor. So, what's all the fuss about balanced about? Why two and not just one? That, dear reader, is a long and involved subject with many twists, turns and surprises. Stay tuned.