How Do USB Microphones Work?

How Do USB Microphone Work

The microphone plays a vital role in audio production. People use microphones for all sorts of purposes that involve audio, including musical performance, recording, and giving presentations or speeches in front of an audience.

A microphone is a device that converts acoustic energy into electric energy. Various microphones are available in the market, including wired microphones, wireless microphones, and USB microphones. In this article, we discuss specifically USB microphones.

What are USB microphones? USB microphones have a converter that can convert an analog signal into a digital signal so that you can connect it directly to the USB port of your computer. They are very easy to set up and do not require any extra equipment to use. Most USB microphones have a headphone port that will enable you to listen to the sound you have recorded on your computer.

One great advantage of USB microphones is that you will find a lot of choices that are cost-effective, and they will allow you to record quality recordings on most of your devices. This article will discuss how USB microphones work in detail and provide information on how to find a suitable microphone for yourself.

How Do USB Microphones Differ From Other Microphones?

A USB microphone is a microphone that has a USB output. Let us discuss how they differ from other types of microphones.

  • An analog microphone can record audio on the computer. Still, you need extra equipment to convert the audio signal into a digital signal so that the computer program can understand. But in a USB microphone, there is a built-in analog to digital converter. You only have to connect it to your computer.
  • USB microphones are portable, so they can be taken anywhere you want with ease. This can be useful if you record audio on the go using a laptop or tablet.

How Do USB Microphones Work?

The USB microphone works quite similarly to other traditional microphones; the only difference is that the USB microphones have an audio interface.

To understand how USB microphones work, you should understand a bit about the traditional microphone.

There are mainly three types of microphones. They are as follows:

  • Moving Coil microphone
  • Condenser Microphone
  • Ribbon Microphone

#1. Moving Coil Microphone

A moving coil microphone is also known as a dynamic microphone. We call it a dynamic microphone because it varies greatly in dynamic range compared to a condenser microphone. 

The moving coil dynamic microphone or transducer converts the acoustic energy into electric energy by electromagnetic induction.

Now, what is electromagnetic induction? When the conductor is kept stationary, and the magnetic field lines are varied, or when the magnetic field is static, and the conductor is varied, the electromotive force or voltage in both cases induces in the conductor, and this is called electromagnetic induction.

Features of moving coil microphones

  • Loud sound
  • Low-frequency signal
  • Do not require any external power
  • Low cost

The dynamic microphone has mainly five components. They are as follows:

  • Diaphragm

It is a thin membrane that is usually present inside the mic. It moves when it is subject to the change in the sound pressure and finally begins the transducer process of converting the acoustic wave into a mic signal. It usually consists of polyester, but the thickness and quality vary from one microphone to the other.

  • Moving coil

The moving coil attaches to the groove of the diaphragm. It is a tightly woven coil and consists of mainly copper in most dynamic microphones. The copper helps to increase the electromagnetic induction and produce a robust audio signal. It is also a very conductive material.

  • Permanent magnet

Magnets produce a magnetic field inside the microphone. Without this permanent magnet, there will not be any electromagnetic induction inside the dynamic microphone.

The magnet ring usually consists of ferrite or neodymium. The poles of the magnet consist of soft iron.

  • Housing

The diaphragm, moving coil, and the permanent magnet are housed inside the microphone.

  • Electrical Lead

After converting the sound signal into an electric signal, the electric signal passes through the electrical lead circuit.

Working Principle

The sound waves cause the diaphragm of the microphone to move in backward and forward directions. When the diaphragm moves, the coil also moves. The coil attaches to the magnet. When the coil moves back and forth in the magnetic field, alternating current induces in the coil rather than direct current, usually taking place in dynamo.

#2. Condenser Microphone

The condenser microphone converts acoustic waves into audio by the electrostatic principle. The condenser microphone is named as such because it consists of a capacitor that plays a vital role in converting acoustic energy into electric energy.

The capacitor consists of two metallic plates placed very close to each other but has a voltage between the plates.

USB Microphone

Features of condenser microphones

  • Suitable for a high-frequency signal
  • Ideal for distant objects
  • Its size is small because there is no coil or magnet inside the mic.
  • It requires an additional power source
  • Some condenser mics are not suitable for loud sounds.
  • The high temperature and humidity can affect the condenser mics greatly.
  • It is a bit complex in comparison to dynamic mics.
  • The condenser mics are expensive.
  • People use these mics in film production

 The condenser microphone consists of mainly four essential components. They are as follows:

  • Diaphragm

The diaphragm is the main component of the condenser microphone. Its movement changes the sound energy into a mic signal and consists of metal that is extremely lightweight.

  • Backplate

The backplate consists of solid brass and plays a vital role in converting one form of energy into another.

  • Housing

The capacitor is present inside the microphone.

  • Electrical Lead

When sound energy converts into electric power, the electrical energy flows in a circuit due to a voltage. The voltage encounters some resistance or impedance, expressed in ohms. 

Working Principle

The diaphragm serves as the front plate of the capacitor in the condenser microphone. When the pressure of the air varies, then the gap between the capacitor plates also changes. So, the voltage in between the plates of the capacitor also changes. This change in voltage is the electric signal.

But this voltage needs some boosting because it produces a minimal current, which is insufficient for working a condenser microphone. That is why it needs a power source for amplifying or strengthening the signal.

There are different ways to amplify the signal:

#A. Phantom Power

This is one of the best power sources for condenser microphones to strengthen the signal. Phantom power is the supply of direct current to the mic for amplifying the signal.

The phantom power or direct current supplies the mic in two ways:

  • By battery that is present inside the mic.
  • The preamplifier or mixer provides the direct current, which is supplied to the mic by cables of the microphone.

The phantom power is usually within 11 to 52 volts. The studio mics need phantom power of 48 volts. You will see a button on the preamplifier labels as 48 volts. You just have to turn on and off this switch as per your requirements. In a cheap or old mixer, you will find a phantom power option to strengthen the signal. You will need to add an external supply of phantom power so that your condenser mics will work properly.

#B. Vacuum Tube

You can supply power to the condenser mics by the vacuum tube to boost the signal. It is one of the oldest methods used for amplification.

#C. Electret

The electret is a dielectric that can supply constant power to the mic. It is a thin material usually applied on the back of the backplate or the diaphragm.

#3. Ribbon Microphone

The ribbon microphone is similar to a dynamic microphone, but the diaphragm shape is a ribbon. The variation in the pressure of sound causes the diaphragm to move. It attaches to the coil. So, when the ribbon diaphragm moves, the coil also moves. The coil attaches with the permanent magnet. When the coil moves across the magnetic field lines, an electromotive force induces on the moving coil. This voltage produces an alternating current. Musicians and engineers mainly use a ribbon microphone.

Analog to Digital Converter

An analog to digital converter is present in the USB microphone, and it converts an analog signal into a digital signal within the microphone. The ADC in the microphone converts the digital signal in different resolutions in different microphones. The digital audio consists of samples, and each sample represents the waveform digitally.

The resolution is expressed in two forms, i.e., sample rate and bit depth.

Sample rate represents how many times the audio samples within a second. The sample rate is expressed in terms of Hertz. Here are some common sample rates:

  • 44.1 kHz
  • 48 kHz
  • 88.2 kHz
  • 96 kHz

Bit depth refers to how many amplitudes each sample has. It is expressed in terms of bits. The most common bits are:

  • 16 bit
  • 24 bit

Applications Of USB Mics

#1. Podcast

A USB microphone is used in some podcasts. The USB microphone has a plug-and-play nature which can make your work easier and comfortable. You just need to connect the USB microphone to the port of your computer and try to record the podcast and share it with everyone.

#2. Quick Recording

If you are a guitarist or a singer and traveling. a USB microphone could be a great portable choice for you. You can record the audio within a few minutes. But you should have a laptop or tablet along with you.

#3. Interviews

Taking wired or wireless microphones in interviews can be inconvenient for you. But if you take a USB microphone, you can quickly eliminate all these problems and focus only on the interview.


The quality of the sound plays a vital role in voiceover. You can have good quality audio just by plugging the USB microphone into the USB port of your laptop.

podcast set up

Benefits of USB microphones

#1. Inexpensive

USB microphones are available at an affordable price. So you don’t have to invest a lot of money if you purchase a USB microphone. If you are a beginner and need only one microphone channel to record audio, USB mics are worth a try.

#2. Simple to Set Up

The simplicity of the USB mic encourages people to purchase this mic. You don’t need any external hardware device for setup. You just have to plug it on the computer, and it is ready to record audio.

#3. Portable

The USB microphone allows you to carry your production easily from one place to another.

Disadvantages of USB Microphones

#1. Low-Quality Materials

Some USB mics are made of low-quality materials to keep their cost low. It is advisable to invest in an better quality USB microphone to avoid need for repairs in the future.

#2. Single Channel Interface

Here, single-channel interface means when you connect the USB microphone to the port of your computer, the computer communicates only with it. It stops connecting with other hardware sources.

You may notice the problem when you connect your computer with more than one microphone.

#3. Latency

Latency means the time taken by any microphone to convert the signal into the sound, which is audible to everyone. Almost all digital microphones have latency, either high or low. Cheap USB microphones have more latency. So the audible sound is a bit delayed compared to high-quality microphones, which can be a problem during a user’s performance.

#4. Digital Resolution

The digital resolution of the USB microphone is lower than other microphone types.

#5. Control

USB microphones do have options to mute or monitor control options. But they don’t have a wide variety of choices to control, like phase flips, as you see in various analog microphones.

How to Use a USB Microphone

USB mics are easy to use. You just have to plug on the port of your computer, and they are ready to play.

The computer connects automatically with the USB microphone via the driver. It automatically chooses the microphone as an input device.

Some models may vary in how they are connected, so take a look at the following steps for setting one up:

  • The USB microphone and computer connect with the help of a cable. You will get the proper USB cable at the time of purchase. So you don’t have to invest separately. Then plug the USB microphone into the port of the computer by the USB cable.
  • The user will download the correct driver to communicate adequately with the computer and the USB microphone. Sometimes your laptop already has a driver to communicate with any external device. 
  • Laptops usually have two locations to plug your microphone. One is for microphones, and the other is for headphones. On the desktop, you will find a jack on the panel of the system. You will also find two jacks. One is for the headphone, and the other is for the microphone. Both the jacks have different purposes. The jack for headphones transmits sound from the computer to headphones to listen to the recorded audio, but the jack for the microphone transmits sound from your USB microphone to the computer.
  • Go to the settings of your computer and select the sound options. Then select the USB microphone as an input device. Choose your output device to be headphones if you want to listen to the audio recordings on your headphones.
  • Check if your USB microphone is muted or unmuted. If it is muted, then turn it on. Now, you may start recording.

Headphone Amplifier

Some USB microphones have a headphone amplifier that allow you to monitor your recording with headphones. Due to the headphone amplifier, the USB microphones tend to have zero latency, which benefits the performer.

Latency is the time taken to process the digital data. It can happen at a higher rate in a USB microphone because the audio signal gets coveted into a digital signal. Then they are fed into the computer. These digital signals are back into the mic by converting into audio signals, which takes time. But the headphone amplifier solves this problem. It works as an output interface.

What Should You Look For in a USB Microphone?

#1. Format of USB Microphone

USB microphones are available in numerous formats like other microphones. Most USB microphones are condenser mics which are best for recording voice or pianos. But if you want to record a loud sound like a drum or guitar, then you will need to choose dynamic USB microphones.

#2. Resolution

USB mics can convert audio signals into digital signals. The best USB mics have a depth of 24 bits and a resolution of 96KHz. But you will find some USB microphones that are limited to 16 bit and 44.1KHz resolution.

#3. Cost

Most USB microphones are available at a low cost while still be fairly durable.

#4. iOS

Most USB microphones available in the market are compatible with iOS. USB microphones that support iOS come in various formats like handheld models for interviews and laptop models for podcasts.

Note that not all USB mics support iOS. Double-check the features of the microphone before you decide on it. Again you need to check the digital resolution of the USB microphone which you intend to buy.

#5. Connections

Some USB microphones have headphone jacks so that the user can connect the headphones and listen to the audio which he has recorded. But all the microphones do not have this capability, so this is something you will want to check before buying if you intend to make use of it.

USB microphone in front of a laptop

Can You Use More Than One Microphones at a Time?

USB microphones always act on a single interface. So can you use more than one USB microphone at a time?

Indeed, yes it is possible. You can record and monitor the audio on your computer by connecting two USB microphones, which can be only possible if you have a new interface that will connect all the signals from each USB microphone that connects with your computer.

Although you can do this process by using software, I will advise you never to try connecting more than one USB microphone to your computer. It will confuse the system, and the audio quality may be inferior. 

But if you have made up your mind to connect two USB microphones at a time, there are numerous ways which you can try doing so:

#1. Try Using Rode Connect Software

If you have a Rode NT USB mic, then use Rode connect software, the best practical method for recording more than two USB mics on a single computer.

When people have more than one USB mic, they connect it to their laptop, tablet, or desktop. The software is free, but Rode NT USB mics may cost you $99.

#2. Voicemeeter

Use Voicemeeter to record the audio using two USB mics on a single computer with a windows operating system. It is free software that can manage different audio sources.


ASIO4ALL is a slightly tricky process. You need separate software, i.e., Adobe Audition, to make use of it.

The audio driver itself is entirely free. It will help you to connect more than one USB microphone to your computer. It even allows you to connect two USB mics of a different model. This software powers your computer’s sound card so that it can access numerous input and output at a time independently.

You first need to download the software from and install the ASIO4ALL driver on your computer. Remember that all the DAW(Digital Audio Workstation) programs will not communicate effectively with ASIO4ALL software. So to communicate two USB microphones with the ASIO driver, you need to open a DAW that is well compatible with the driver.

Now you need to open the settings of ASIO4All and then click on the USB microphone to activate it. Now the DAW will recognize each microphone from the interface. Then select each microphone that needs to be input into the system and start recording the audio.

#4. Use Numerous Computer

You can use multiple laptops if you want numerous USB microphones at the same time. Connecting one USB mic to each computer may seem like an easy process compared to the above, but when you combine all the audio signals, it can take a lot of time.

Frequently Asked Questions

#1. Are USB Mics Any Good?

USB mics can certainly be good if you choose a reliable one. They are portable and convenient to use, and are generally less expensive than other types of mics.

You don’t need to invest in a sound card when purchasing a USM microphone. The computer has an inbuilt sound card to play the sound.

#2. How Do I Fix My Microphone Quality?

To fix the quality of the microphone, you need to follow the below steps.
– Go to the control panel of your computer.
– Click on hardware and sound.
– Click sound and choose headset mic.
– Right-click on the headphone and select properties.
– Click levels and adjust the mic’s sensitivity.

#3. How Do I Make My Microphone Sound Clearer?

You can make the microphone sound clear in the following ways.

– You should switch off any device producing noise in the room where you are recording audio by the microphone.
– You should keep your microphone at some distance away from your mouth.

Parting Words

The USB microphone is quite widespread nowadays due to its affordability and ease of use. You can carry this microphone anywhere you like for recording audio. They can be a great value of recording audio if you choose a good model from a reputable company.

I hope this article has given you enough information regarding the USB microphone and its workings. Please share your suggestions and any questions you have about this article in the comments below.

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