Have you been hearing “XLR this that” for a while and are mildly curious, or you’re just a techie seeking greater in-depth knowledge?
In this article, I show you what XLR stands for and other things you should know about it.
Let’s get started:
Seriously, What Does XLR Stand For?
An XLR is a microphone cable. It typically has three pins and a connector used for transferring electrical signals.
In “XLR”, the X stands for X Connector, L for Locking Connector, and R for Rubber Boot. It’s an abbreviation for an audio transmission cable that has external noise protection when plugged into your microphone.
Not all microphones use XLR and the function of an XLR isn’t limited to just transmitting clean sounds only. As a microphone connector, It also carries balanced-line level audio.
Now the question is…
How Does It Work?
XLR cable connectors come in two primary transmitters;
- XLR Input.
- XLR Output.
The input XLR is a female connector with pins while the output XLR is a male connector with holes.
Here’s the respective working process:
To use a female XLR, you fuse it to your live equipment, letting the earthing pin make the first contact before the other 2 pins.
To use the male XLR, hook it up to the jack pins of your audio output system such as the speaker.
In other words:
The male XLR connectors AKA the ‘plugs’ are often panel-mounted, sometimes even inbuilt in a microphone while the female ‘sockets’ are free connectors.
The sockets receive the plugs and establish a signal flow. This process is kinda typical in any microphone connector, not just the XLR type.
This setup helps to provide additional protection against interference, whether electrical, radio or other types.
Why The XLR?
What makes the XLR cable special?
It Creates A Balanced Audio
Let me start off with an explanation of what balanced audio is:
Microphones operate at low frequencies. They typically require hefty amplification through an amplifier to reach the speaker level sounds you hear. We refer to these as mic level and line-level audio respectively.
Electrical, magnetic and radio interference are the common noise types that plague microphone audio transmission.
When these noises, though relatively minimal, reach the amplifier, they are magnified in volume to ungodly proportions.
And that’s where the audio balancing comes in;
Balanced audio is free from all that distracting noise. And it’s possible by carrying dual copies of the audio signal along with two connectors in a reversed polarity.
This arrangement inverts the signals once again and combines them at the amplifier, thereby eliminating most of the noise. The end result is a pure audio signal.
Amazing, isn’t it?
Now, though, the XLR cable would otherwise encounter electromagnetic interference with the signal travelling its length.
There’s a process called Common Mode Rejection that allows the next audio device to get rid of the induced interference.
See the video from All About Electronics explaining everything about Common Mode Rejection.
This process uses what is called a microphone preamplifier and a differential amplifier.
It Offers An Effective Microphone Protection
Remember what we said earlier about the XLR’s unique design that allows the earthing pin to make the first contact?
Well, it has everything to do with the microphone’s electrical transfer.
What is phantom power?
Phantom power refers to the external power that active microphones require to operate and it comes in the form of a DC electrical transfer.
Now get this,
This transfer happens on the signal lines across pins 2 and 3 of a standard 3-pin XLR, the industry standard for microphones. Of course, microphones that do not use phantom power are designed to block the transfer.
Were pin 2 were to be connected first, or pin 3, would result in an electrical shorting, something which the XLR prevents with its design.
Balanced audio and protective effects are what makes the XLR so valuable.
Still, have some questions? Read on!
Why is it called XLR?
This has to do with the history of the cable connector. Now, not to bore you with the long details, but the letters stand for the Cannon X-Series connector with Latch and Rubber.
The latch there was a locking mechanism introduced to the X-Series while the rubber has subsequently been phased out of design.
Check the video here for a detailed evolution of the XLR.
Can The XLR Only Be Used For Audio?
Of course not!
The XLR is rather versatile and can also be used for video and stage lighting.
Does the XLR come only with 3 Pins?
The XLR comes with multiple pin configurations, up to 10 pins currently. The most ubiquitous is the 3 pin configuration used with microphones that has the first pin as the ground/shield pin with the second and third as the positive/hot and the return/cold signal lines respectively.
There is however still the 4 pin configuration that works with intercom headsets and is widely used in electronic systems.
And much, much more.
Is There A Smaller Version Of XLR?
For any who find the full-size XLR either large or cumbersome for whatever reason, there is the mini XLR connector which comes equipped with up to 8 pins to cater to all your needs.
As a curious enthusiast or a working techie, this article shows you all there is to know about the XLR cable connector.
If you have further questions, kindly use the comment section below. Until next time, rooting for you.