What Does XLR Stand For?

In audio production, we need cables for a number of things.

Perharps the most important use for cables is to connect our gear accordingly and help us use our equipment more efficiently.

One cable and connection type that is popular in audio production is called the XLR.

You’ll find most recording microphones with XLR connections . This connection type is one that you also find on audio interfaces as well as most instruments.

With this simple description we can already fairly establish that XLR connections are important.

One question that a newbie music producer asked me recently is what the letters XLR actually stood for. I therefore thought this article would be a great idea to fully write about this.

With that said, What does XLR stand for?

XLR stands for External line return. It is a type of electrical connector that is found mostly in professional audio, video, and stage lighting equipment. XLR Connectors are generally associated with audio equipment such as microphones, speakers, amplifiers, and soundboards, however, are also used with lighting control, low-voltage power supplies, and more.

Uses of XLR cables

Perharps the most important quality of XLR cables is that they’re balanced.

This means that they’re suitable for both live sound applications and recording studio applications.

XLR cables are used for connecting most microphones. Because microphones often require a power source, some mixing boards are designed to provide power.

This is called “phantom power.”

XLR cables allow mixing boards to deliver phantom power to microphones. Most cables simply cannot do this.

How XLR’s Work

When two balanced devices are connected, the XLR cable delivers a positive audio signal, a negative audio signal and a ground signal.

The positive audio signal and the negative audio signal are identical, but they are inverted.

If electrical interference is encountered, that noise enters both the positive audio signal and the negative audio signal.

When the positive and negative signals reach the balanced device at the end of the chain, one of the two audio signals is inverted.

Now the two audio signals are identical in every way. However, the noise that was on the audio signal has now been inverted.

When the inverted noise is combined with the original noise, they basically cancel each other out.

All that is left is the original clean audio signal.

The design of XLR’s

XLR connectors are available in male and female versions in both cable and in chassis mounting designs, a total of four styles.

This is a bit unusual as many other connector designs omit one of the styles usually a chassis mounting male connector.

The female XLR connectors are designed to first connect the earth pin, before the other pins make contact, when a male XLR connector is inserted.

With the ground connection established before the signal lines are connected, the insertion (and removal) of XLR connectors in live equipment is possible without picking up external signals (which is usually the case with connections like RCA).

The number of pins also varies.

As of 2016, XLR connectors are available with even up to 10 pins, and mini XLR connectors with up to eight. XLR connectors from various manufacturers will intermate, with the exception of six-pin models, which are available in two incompatible designs.

The older Switchcraft six-pin design adds a center pin to the regular standard five-pin design, whereas the newer Neutrik design is a different pattern.

The Switchcraft six-pin female will accept a standard five-pin male plug whereas the Neutrik six-pin design won’t.

The terminology for basically labeling the corresponding members of a pair of mating connectors follows the usual rules for the gender of connectors: a ‘male’ connector is the one with pins on the smallest element, ‘female’ has matching receptacles.

A ‘plug’ connector enters the ‘socket’ connector, judged by the largest element. For most XLR, plugs are male and sockets are female.

XLR are unusual as, at least in audio applications, all four combinations of male and female, plugs and sockets are equally common.

A common misconception is that ‘plugs’ are free connectors and ‘sockets’ are panel-mounted, but XLR uses many free female sockets and panel-mounted male plugs.

There is a loose convention for audio work that signals are generated by equipment with male pins and transmitted to those with female receptacles.

The circumference of an XLR connector at the widest point is around 59.7 mm (2.35 in)

Final Thought’s

XLRs are the standard in most audio equipment and the recommended cables when dealing with instrumentation and recording equipment.

Their noise canceling effect enable them to provide clean signals without running into noise issues.