“The nice thing about standards is that you have so many to choose from!” These words, written by computer scientist Andrew S. Tanenbaum, could never be more true. We have so many standards out there, that it really can defeat the purpose of the whole thing.

Thankfully, we have a standard for wiring XLR connectors used in audio (mic level & line level) and lighting control (DMX) applications.

3 Pin XLR Wiring Standard

3 Pin XLR connectors are standard amongst line level and mic level audio applications. The above diagram shows you the pin numbering for both Male and Female XLR connectors, from the front and the rear view. (the rear view is the end you solder from)

Here are the connections on each pin:

• Pin 1: Shield / Ground
• Pin 2: Positive
• Pin 3: Negative

What colours do I use? I’ve searched long and hard for a definitive colour code. So far, I cannot find one. The hassle is partially that every cable uses different colours. As a generally rule:

• Pin 2 (Positive): Red
• Pin 3 (Negative): White or Black

This, at the very least, is what I use for the majority of my mic leads and patch cables. It also kinda matches up with the Australian colour coding for 240V wiring. Kind of.

Some cables will provide you with an actual data sheet specifying the colour codes – this happens mainly in multi-pair cables and not so much with two pair mic cable.

As I said, there is no hard and fast rule. The important thing here is to pick a colour scheme and stick to it. If you have a better rule, post it in the comments below.

5 Pin XLR Wiring Standard

5 Pin XLR connectors are used primarily in lighting control applications as a DMX signal. The DMX specification allows for two completely separate data channels over the one 5 pin connector, but often you’ll find the cable manufacturers cheap out and only provide a single channel. Here is the DMX pin out:

• Pin 1: Shield (Common)
• Pin 2: DMX 1 Negative
• Pin 3: DMX 1 Positive
• Pin 4: DMX 2 Negative
• Pin 5: DMX 2 Positive

Interesting, the positive and negative are backwards with DMX. Don’t ask me why. I don’t know.

What colours do I use? Again, there is no standard I am aware of. As I don’t do much 5 pin XLR wiring, I can’t offer up my own suggestions either. Just make sure you use the correct wire pairing if you are adding the second DMX channel on the one cable (mixing up your twisted pairs can un-do the purpose of twisted pair cable in the first place)