A microphone, on the face of it, seems like a simple thing. It is just a piece of equipment that makes audio signals from sound waves. It might be technical in its process, but you get your mic out of the box and plug it in, and it works.
Not quite as simple as that, of course. After all, what do microphones plug into? And how does that work? What sort of plug do they use?
You might think there might be one or two options, but you would be wrong. There are quite a few. That’s why I have decided to take an in-depth look at each of them with a brief description. So, let’s get started…
What Equipment Do Microphones Plug Into?
There are quite a few options for that as well. Furthermore, these days some don’t seem to plug into anything at all. A radio mic is an example where a battery powers the mic and sends the signals to a receiver. The mic itself is not actually plugged in. But we are discussing mics that do plug in and what microphones are plugged into.
Microphones can be connected to a variety of equipment. These are just a few.
- Stand Alone Preamps.
- Audio Interfaces.
- Computers and smartphones.
We shall look a little closer at them later. And to go with that list, there is a range of different connections that the various pieces of equipment use. It is those connections we are going to concentrate on here. Let’s look at the connector options first. What they are for, and how they are wired.
Then we can look at what microphones can plug into. And what better place to start than with possibly the most important connector for microphones we have.
What are the Different Microphone Connectors?
The X connector was first created in the 1940s by James Cannon and his company Cannon Electric. It later became the XL when a securing or latching mechanism was fitted in the 50s. The basis of the XLR, as we know, it came in the 50s when he attached synthetic rubber neoprene for insulation.
Other companies then made their own improvements, which again improved the overall design. And today, we have the XLR that we all know and love. There are 3-pin to 7-pin designs, all with different functions.
The XLR isn’t only used for audio. However, we are going to stick to microphone fittings here. Let’s start with one we all know.
For the professional mic, this is probably the most common microphone connector. The three pins include a shield or ground on Pin 1. Pins two and three are balanced audio. They carry the same signal but in opposite polarity. Pin 2 has the positive signal, and Pin 3 has the negative.
So the wiring is:
- Pin 1 – Shield or Ground.
- Pin 2 – Mic audio signal in Positive polarity.
- Pin 3 – Mic audio signal in Negative polarity.
The 4-Pin XLR has a couple of options for use and is wired accordingly. For microphones that include headsets, the wiring is like this:
- Pin 1 – Shield or Ground.
- Pin 2 – Mic Audio signal unbalanced.
- Pin 3 – Headphone Shield or Ground.
- Pin 4 – Headphone signal in mono unbalanced.
Next, we have microphones used for radio or broadcasting, which often have an LED light built-in. In that case, the wiring is like this:
- Pin 1 – Shield or Ground.
- Pin 2 – Audio signal Positive polarity.
- Pin 3 – Audio signal Negative polarity
- Pin 4 – LED light.
The 5-Pin XLR similarly can be wired in two different ways. Again this depends on what function the mic is serving. The first function could be for Stereo microphones or dual-element microphones that are used outdoors. These are wired thus:
- Pin 1 – Shield or Ground.
- Pin 2 – Element 1 audio signal, positive polarity.
- Pin 3 – Element 1 audio signal, negative polarity.
- Pin 4 – Element 2 audio signal, positive polarity.
- Pin 5 – Element 2 audio signal, negative polarity.
In the case of intercom headsets, or a set of headphones with a mic in stereo, it is wired like this:
- Pin 1 – Shield or Ground for the microphone.
- Pin 2 – Audio signal from mic unbalanced.
- Pin 3 – Shield or Ground for the headphone.
- Pin 4 – Headphone signal, left channel, unbalanced.
- Pin 5 – Headphone signal, right channel, unbalanced.
This is used for stereo headphones with a balanced microphone. The wiring is:
- Pin 1 – Shield or Ground for the Microphone.
- Pin 2 – Audio Signal from mic, positive polarity.
- Pin 3 – Audio signal from Mic, negative polarity.
- Pin 4 – Shield or Ground for Headphones.
- Pin 5 – Headphone signal on the left channel, unbalanced.
- Pin 6 – Headphone signal on the right channel, unbalanced.
7- PIN XLR
The uses for the 7-PIN XLR can be a little confusing. It is sometimes used to power up a tube condenser mic. The standard +48v Phantom Power is not enough, and so the 7-PIN supplies the power those mics need.
Wiring can vary between these mics, but they usually are set up similar to this:
- One connection for Shield or Ground.
- Two connections for the balanced audio.
- Two for DC bias voltage.
- Two wires for the heater circuit of the tube.
The Mini XLR
This is a connector that was created by Switchcraft. You will often find it being used to connect Lavalier mics. But also some mics used in studios. It can also be known as either TA3 or TA4, depending on how many pins it has. TA3 has three pins, and TA4 has four.
As you may have guessed, it looks very much like the full-size XLR but is a smaller version. There are no set wiring arrangements for either TA3 and TA4, but these are guidelines to the most commonly used wiring patterns:
Mini XLR 3-Pin (TA3)
- One connection to Shield or Ground.
- One connection for DC bias voltage.
- One for unbalanced audio.
The DC bias voltage provides power for the Electret mics impedance converters.
MINI XLR 4-PIN (TA4)
- One connection to Shield or Ground.
- One connection for DC bias voltage (again for the impedance converters).
- One for the unbalanced audio.
- One connection for a 20k ohm resistor, which is between the mic input and the power.
TS or Tip Sleeve Connections
These are the connections you will mostly find on standard consumer mics. They come in two sizes, ⅛-inch and ¼-inch. There are two pin connections:-
- The Sleeve – Shield or Ground.
- The Tip – unbalanced audio signal from the mic.
TRS or Tip-Ring-Sleeve Connector
The TRS connector is similar to the TS. However, in some mics, the TRS may carry balanced audio. As with the TS, you will find it mainly in either ⅛-inch or ¼-inch sizes. Connections are:
- The Sleeve- Shield or Ground.
- Tip – Audio signal from mic, positive polarity.
- Ring – Audio Signal from mic, negative polarity.
Another variant is the TRRS connector. These are often found in ⅛-inch sizes and are sometimes referred to as mini-jacks, or Aux jacks. They’re usually used in headsets or to connect to phones or other devices.
There again are no hard and fast rules about standard microphone connections. You will normally find the Tip is for left-side audio. But the ring can be for the right side audio, ground, or the microphone. The sleeve, in turn, can either be for the ground or the microphone.
This is a connector that is often used to connect Lavalier mics with wireless transmitters. The pins have no formal standardized arrangement and are often used for a range of functions. Sometimes some of the pins aren’t used at all. On that basis, it isn’t possible to suggest common wiring connections.
Power Supplies for Tube Mics
Tube mics connect up to power supplies and send their signals through the supply. This can be done with an XLR 7-Pin, as I have already mentioned. Once again, there are no formalized standards, especially if the mic has its own output connection and cable.
Some Outdated connectors
You will occasionally find Nexus, Tuchel, and 2501 connectors. However, these are now rather outdated, and you will rarely come across them.
If you do have older microphones that use these classic connectors, just make up (or get an engineer to do it for you) some short adapter cables, with, for example, a Tuchel connector on one side and an XLR on the other. Then just use them as normal with an XLR to XLR of any length you need to extend them.
So, What Do Microphones Plug Into?
This is a brief list of all the things microphones usually plug into:
- Input for a Microphone preamp including Mixers, Recorders, Interfaces, etc.
- In-Line Devices.
- Active or Powered Speakers.
- Guitar or Bass amps.
- Audio Snakes.
- Other devices include a computer, camera, or smartphone.
Let’s consider them individually…
Microphone Preamp Inputs
This can be a Mixing desk/console/table, an Audio Interface, or another kind of Recorder. The audio signals that are output from a mic need to have some gain applied. This is the role of the preamp.
The output level of a microphone needs gain to be increased from Mic level to Line level. Then it can be used in professional equipment. That is why when you are using a standard mic, it will always be connected to a preamp.
The quality of the preamp can have a significant effect on the sound the mic produces. They are built-in to mixing consoles, audio interfaces, and audio recorders to achieve the gain necessary.
An In-line Devices
An In-line device can be best described as a device that will sit between the mic and the preamp. They are positioned there for several reasons and often act as filters. They can include:
Or to give it its full name, a Passive Attenuation device. This is usually built into the mixer or interface. Its job is to decrease the strength of the signal by a certain level of dB before it even reaches the preamp when recording very loud sources. This allows you to get a suitable recording level and reduces the risk of potential distortion.
These filters will attenuate, or remove, any frequencies that occur below a cut-off point that you can define. It will allow frequencies above the setting to pass through.
These are filters for removing Electromagnetic interference. They will remove any electromagnetic noise or radio frequencies from the microphone’s signal.
Stand-Alone PreAmp or Mic Booster
There will be occasions with some mics where the signal needs an extra boost. That is before the signal even gets to the preamp. This can be the case with some low-sensitivity ribbon or dynamic mics.
The TRITON AUDIO FetHead in-Line Microphone Preamp and the Cloud Microphones Cloudlifter CL-1 Mic Activator are two high-quality and highly recommended options. Or, if you want something a bit cheaper, go for the Klark Teknik Microphone Preamp (MIC BOOSTER CT 1).
If you have an active speaker or powered speaker, you can plug the mic straight into that. You don’t need a preamp in that situation. That is because the amp that is built-in to the speaker will be powerful enough to boost the signal to a usable level. The speaker then will reproduce the mics signal. Of course, what the sound quality will be like is another discussion.
Guitar or Bass Amps
Amplifiers expect to receive instrument-level signals. They will accept mic-level signals, but you may need an adapter. If you have an XLR plug on your mic, it means it is going to be low impedance.
If the mic has a jack plug, TRS, etc., it will be a high impedance. The TRS fitting on your mic is going to work better with your guitar amp. However, you can get adapters that will match up the mic to the amp and differing impedances.
Although, to be honest, unless money is a massive issue, running a microphone through a guitar amp rarely produces good results. They do, however, work far better with Keyboard amps, if you happen to have one of them?
It is a strange name, but it is just a single multi-core cable with multiple inputs and outputs for microphones. You can plug several mics into a single snake. All the signals are then traveling in one combined cable. Additionally, you can get Analog and Digital snakes.
There are quite a few devices these days that carry an audio input. Computers, Cameras, and Smartphones come to mind. If you are considering using a mic with one of these devices, you will need to make some checks.
Computers and Phones will usually be able to boost the mic level to some degree if required. But with cameras, you will need to ensure the input is mic level.
How They Plug In
So there we are. A fairly detailed answer to the question, “What do microphones plug into?” In the majority of cases, they will all work fine. But, it is good to know the options and what the mics and the fittings are best suited for.
If you are thinking of buying a mic for your home studio, but are on a budget, this is a great XLR Condenser Microphone that includes everything you will need.
Or for your camera, there is this Movo DOM1 3.5mm TRS Lavalier Omnidirectional Condenser Microphone for Camera. And for a TRS to XLR converter, there is this DISINO 1/4 Inch TRS to XLR Male Balanced Signal Interconnect Cable.
Need a Great Microphone?
We can help you find what you need. Check out our in-depth reviews of the Best Cheap Microphone Under $50, the Best Condenser Microphones, the Best XLR Microphones, the Best Dynamic Microphones, the Best USB Microphones, the Best Lavalier Microphones, and the Best Computer Microphones you can buy in 2023.
Also, take a look at our detailed reviews of the Best Live Vocal Mics, the Best Vintage Microphones, the Best Microphones For YouTube, the Best Microphones For Recording Electric Guitar, the Best Snare Mic, the Best Kick Drum Mic, the Best Wireless Microphones, and the Best Interview Microphones currently on the market.
What Do Microphones Plug Into? – Final Thoughts
Can I plug my mic into a Line input? Physically you can, but I wouldn’t recommend it. A mic will give you a mic-level signal. The Line input is expecting Line level signals, not Mic level. And a Line level signal is much stronger than a mic level signal.
Therefore, the signal from the mic will be low level and not loud enough. It will also generate a poor signal-to-noise ratio. So the answer to the question is that it is not a good idea.
Until next time, make yourself heard.