XLR connectors are balanced line connectors. They are also known as Cannon connectors, based upon the last name of their inventor, James Cannon. The most common Cannon connectors, or XLRs, each have three wires: the hot lead, the common lead and a separate ground. They are used where it is necessary to minimize extraneous electronic noise, most commonly in microphone cables.
Ground is always pin "1". The so-called "hot" lead is always pin "2." The "3" pin is the "cold", or return, lead, which is actually what makes the line "balanced". Prior to this standardization, some manufacturers would reverse the leads of pines "2" and "3".
Instructions
Wire by the numbers
1. XLR plugs (male) and sockets (female) are most frequently used in professional audio and video electronics cabling applications. The design "grounds" the connection before the leads are joined.
Looking at the 'holes' of a female connector, the top left hole is "2", top right is "1", and bottom is "3". Looking at the pins of a male connector, the top left pin is "1", top right is "2", and bottom is "3". Connecting wires "number for number" is always the way to ensure a correct connection.
2. Follow the color connections of the wires to further ensure consistency between balanced line sources. Strip about 3/8" wire to connect to the post. Heat solder the black wire to pin "2" on both the male and female connectors.
3. Strip about 3/8" wire to connect to the post. Heat solder the white or red wire to pin "3" on both the male and female connectors.
4. Strip about 2" of braided insulation and twist it into a wire about 3/8' in length to connect to the post. Heat solder the braided shield wire to pin "1" on both the male and female connectors.
5. The three-pin XLR, aka XLR3, has a 5-pin sibling (XLR5) that is used as the standard connector for DMX512 digital lights, dual-element mics and dual-channel headsets. The wire connections, however, are the same three pins as above, with the remaining pair being devoted to remote device protocol (RDM) and control networks protocol (ACN).
Tags: both male, both male female, connect post, connect post Heat, female connectors