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Why Do Microphones Use XLR Cables?

Have you ever wondered why your voice sounds so horrible on the headset that came with your smartphone? You may think it’s because the mic on the headset is crummy. Sure, it probably is, but that’s not the whole story.

Bob Dylan recorded multiple albums way before smartphones came along. Yet, he sounds better than you when you talk or record something on your Samsung Galaxy 10. And he’s Bob Dylan! Surely there must be some explanation for this affront.


Indeed, there is

First of all, no, you do not sound worse than Bob Dylan. And your headset’s quality is not entirely to blame either. A lot of it has to do with the type of microphone connection you are using.

Sneaky old Bob, when he used microphones, he used XLR cables for his connections. Your poor old smartphone uses a TSR 3.5mm connection jack or something like that. The fact of the matter is that Bob had the better audio equipment.

That may not be breaking news, but it should prompt a question. Why? Why does Bob Dylan sound so clear compared to the average headset or university lecturer with a clip-on mic? Perhaps you’re asking the wrong question. Maybe you should be asking, “Why do microphones use XLR cables?”

What is an XLR Microphone?

What is an XLR Microphone

In technical terms, there is no XLR microphone. That is because XLR refers to a specific connection type used on certain microphones. The most common microphones that use an XLR cable are dynamic and condenser microphones. Additionally, professional microphones are designed to use an XLR cable connection.

Conversely, there are certain types of microphones that never use XLR cables, USB microphones. This is because USB mics are, well, meant to connect to USB ports on computers. However, you may find some USB microphones that have a USB AND an XLR connection to give you the option of how to connect them.

The Essential Microphone Cable

The bottom line is that professional studios and live performances around the world use XLR cables to connect microphones for recording and live playback purposes. Primarily for music recording, but also audio tracks for video and film production. As well as press conferences, sports events, and TV sitcoms.

You have probably seen some “behind the scenes” footage of someone holding a long black pole with a microphone on one end while an actor messed up their line or something. That person holding the pole is called a “Boom Operator.” Their work is so important they are listed in the end credits of any movie.

Likewise, you may notice the boom operator has a large bag with a shoulder strap hanging in front of their waist. What do you think is in that bag? That’s right, a recorder and a whole lot of XLR cable.

Parts of an XLR Microphone Cable

A standard XLR cable has two different ends, a male and a female, although, for specific purposes, a cable could have two males or two females. It’s easy to tell the two apart. The male XLR connector has pins that point outward, while the female XLR end has holes where the pins fit.

Yes, it’s as basic as that. And it’s something you can keep in mind for all kinds of audio and electrical gear. The female connector is the one that connects to the microphone, and the male end connects to the mixing desk, PA, amplifier, preamp, or DAC.

Advantages of an XLR Microphone

Since we are asking, “Why do microphones use XLR cables?” we should probably get to answering that. The main reason XLR cables are used to connect microphones to mixing desks or various other audio capture devices is “balanced audio.”

But, what is balanced audio?

Well, it is a way of connecting audio equipment so that the audio signal can travel through a cable of any length without losing the signal’s initial clarity. In the most basic terms, it means, “what goes in, is what comes out.”

To do this, XLR cables send two copies of the audio signal at the same time. Furthermore, those signals are sent via reversed polarity, which works to cancel out electromagnetic interference. As a result, the audio signal received maintains the clarity and accuracy of the original microphone input.

If the two signals are not sent in reversed polarity, all manner of interference can affect the audio signal, which leads to poor audio capture and reproduction. Resulting in a loss of frequency detail, if not outright unwanted noise.

How XLR Connections Work

How XLR Connections Work

As mentioned, there are three pins on the male connector and three holes on the female connector. Each pin has a specific function that allows XLR microphone connections to deliver balanced audio. And each pin connects to a specific port to complete the link. So, let’s have a quick breakdown of what the three pins on an XLR cable do.

  • Pin 1 – The ground or “shield” wire. It serves as a reference for the other two pins, acts as the ground for the microphone, and shields Pin 2 and Pin 3 from signal inference and damage. If you ever received a shock from a mic with an XLR cable, it is because Pin 1 is broken in some way.
  • Pin 2 – The positive or “hot” wire sends the positive polarity audio signal from the microphone to the input.
  • Pin 3 – The negative or “cold” wire sends the negative polarity audio signal from the microphone to the input.

The three wires that make up an XLR cable work together to ensure the audio signal’s accuracy and clarity. This is because a reversed polarity signal (a positive and a negative version of the same signal) is being sent at the same time.

In the piece of equipment where an XLR cable connects, such as a DAC, there is typically a microphone preamp. The preamp can “balance” two signals, resulting in a differential sum. In other words, the best combination of the two signals.

The microphone preamp can also “filter” out electromagnetic interference by comparing the signal from Pin 2 to Pin 3. However, this does not make XLR microphone cables immune from electromagnetic interference (EMI). They are just better at blocking various types of EMI than are other non-XLR mic cables.

For that very reason

Professional recording studios will have XLR cables between the microphones and dedicated microphone preamps (either within a console or interface, or standalone). Those preamps will then connect to the recording equipment. As a result, they end up with high-quality audio capture and reproduction. If you want proof – Bob Dylan.

Looking for a Great Microphone or Mic Gear?

Then check out our in-depth reviews of the Best Live Vocal Mics, the Best XLR Microphones, the Best Dynamic Microphones, the Best Condenser Microphones, the Best Snare Mics, the Best Drum Mic Kits, the Best Kick Drum Mic, and the Best Wireless Microphones you can buy 2023.

Also, take a look at our detailed reviews of the Best XLR Cables For Microphones, the Best Microphone Stands, the Best Microphone Preamps For Home Recording, the Best Microphones For Recording Vocals, the Best Interview Microphones, and the Best USB Microphones currently on the market.

Why Do Microphones Use XLR Cables – Final Thoughts

There’s a simple answer to this question – because they are sonically the best. No one has yet to see a professional recording studio with only USB microphone cables. Nor are they likely to for the foreseeable future. For all the advantages that digital this and that can offer, at the moment, it can’t quite get sound right.

That’s probably because sound is physical. Sound moves, and it can be felt. It’s why XLR cables work so well at capturing audio – they use electricity. And electricity is most definitely physical. And XLR cables use the movement of electricity to their advantage.

Perhaps someday, digital technology and cables will close the gap. But that day is not today, and for the best microphone audio capture, there’s no beating a good old XLR cable.

Until next time, make yourself heard.

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About Corey Hoffman

Corey is a multi-instrumentalist who has played in numerous bands over the years, some good, some not so good. He has also written countless songs and recorded five albums in professional studios across America. Today he is a hobby musician but still loves the guitar after over 15 years of playing.

He considers his writing as a way to share what he has learned over the decades with younger generations ad always can't wait to get his hands on the latest gear.

He lives just outside New York with his wife Barbara and their two German Shepherds, Ziggy and Iggy.

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