What is an Audio Interface?

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An audio interface is a piece of hardware that is essential for audio production no matter what software you use for recording and mixing.

Connecting an audio interface to your computer allows you to utilize multiple inputs and outputs to record and monitor your sound.

Many audio interfaces today are equipped with a variety of features and abilities, so it’s important to understand what they can provide and what you might need before purchasing one for your home studio.

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home audio production

What does an audio interface do?

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Connecting to a Computer

Before researching audio interfaces, you need to know a few things about your computer starting with the operating system.

An audio interface can connect to desktops and laptops alike, but some can only operate with windows, or Mac, or both.

If you have a machine running Microsoft windows, for example, you would need to be sure that the audio interface you’re interested in works with your version of windows.

You may also be interested in an audio interface that works with more than one operating system if you have two computers or plan to use it on a machine other than your own.

It is also important to take note of the types of ports on your computer. Most audio interfaces connect via USB, but some work by connecting to a thunderbolt port or other connection.

Many audio interfaces use USB 2.0 connections, and can be used with USB 2.0 and 3.0 computer ports.

Another thing to consider is that some software works best with specific audio interfaces. Make sure that your potential interface works with your DAW (digital audio workstation) before investing in a purchase.

Although many interfaces have software in conjunction with the hardware, such software is used for setup and quality purposes and do not replace your favorite audio software.

Additionally, some audio interfaces can connect to mobile devices such as iPhones or tablets, but often require an extra adapter or cable to do so.

For this reason, it’s important to consider what ways you’ll be recording with your audio interface as you shop for the best products and build your ideal studio at home or at work.

Converting Audio

Imagine that you’re singing into a microphone, which is connected to an audio interface connected to your computer.

shure microphone

The first thing your new hardware will do is convert the physical vibration of sound into an electric signal. The sound will then travel down the microphone cable to the audio interface.

The new signal will be boosted by a built-in preamplifier to make the sound level louder and higher quality.

This will then be converted by the audio interface into data that your computer can comprehend, creating recorded sound waves that you can edit, mix, and otherwise manipulate later on.

At the same time, the sound will be sent from your computer software back through converters which enable you to listen to the audio sent by the inputs through outputs on your audio hardware.

Inputs and Outputs

The most basic of audio interface models have two inputs and two outputs and always run in pairs of two.

The Scarlett 2i2 or 2i4, for example, is a budget friendly two in and two out audio interface that can be a great way to start out or work on projects that don’t require many inputs and outputs.

On the other hand, this audio interface has sixteen inputs and is built for maximum power. Odds are, you will probably want to find a sweet spot somewhere in the middle, perhaps with something more along these lines.

Inputs are typically XLR microphone cables or 1/4 lines. These are used to record voice or instrumentation.

Outputs are mostly 1/4 lines, but many audio interfaces have one headphone jack for a traditional headset as well. Types of outputs can include headphones, speakers, or in-ear monitoring devices.


Today’s audio interfaces also come with an input and output for midi devices.

Midi, which stands for musical instrument digital interface, is a key player in most audio software and allow for the connection of a midi keyboard or controller to the computer.

By using an audio interface’s midi input, you can use a keyboard to play software instruments inside your production software.

Similarly, using the midi output lets you connect a synthesizer or drum machine to your audio interface to play the notes recorded into your software of choice.

Midi inputs and outputs are ideal for people working with software based sound or synthetic instrumentation. Knowledge of midi devices are not vital to choosing the ideal audio interface, but can be a useful addition to your gear.


Midi can be useful in your audio production if you lack the ability to find someone who can play the instrument you need for your recording or performance.

There is a lot to learn about the topic, but you might find it a fun and useful dive into advancing audio tech.

Start with this explanation and information, and maybe try midi with your audio interface next time.

Audio Quality

The quality of your sound is vital both when recording and listening.

To get the most out of your audio interface, some knowledge of analogue audio and related terminology is key to optimal sound.

High quality mic preamps and audio converters are crucial to a solid audio interface, but there are other factors to consider as well in order to produce the best sound possible.

In case you enjoy all the complex technical details, this Sweetwater article explains more about what a preamp is and why they are such a key part of all audio interfaces.

Sampling Rate and Bit Depth

Sampling rate and bit depth are often mentioned when talking about audio production.

A sound’s sampling rate relates to how often the converter of an audio interface looks at the audio and converts it to data. This is usually described in terms of kilohertz, or KHZ.

Bit depth describes the length of the data sequences produced by audio interface data conversion.

The important take-away from all these technical terms is simple. Basically, the higher the sampling rate and bit depth are, the better the sound, but the larger the files are.

Many people recording today use audio settings of 24 bit 96 KHZ. However, 16 bit 44.1 KHZ is typical CD quality and is also acceptable.


Although the conversion of data and sound may seem instantaneous, it’s not.

Since an audio interface takes input from a source, converts it, and brings it out again, there can be a slight delay or latency. A typical amount of latency is only a small number of milliseconds, or thousandths of a second.

audio interface cables

Still, this can be frustrating and distracting when working with sound. Thankfully, there are ways of combating and minimizing audio latency.

In your audio software, it is possible to change the buffer size, which is the amount of time the computer takes to process sound.

Lower audio buffer sizes mean less latency, but also put strain on the computer and can have undesirable effects on what you’ll hear.

The other method of avoiding latency is to use a feature commonly added to audio interfaces called direct monitoring or zero latency monitoring.

With this method, the audio interface bypasses the computer so that the inputs and outputs communicate directly with each other.

Sometimes, this is done with a switch on your audio interface, and other times added into the effects the audio interface offers.

Other Features

Many popular audio interfaces go far beyond inputs and outputs.

While you might decide you don’t require extra bells and whistles, they can be excellent additions to your gear and send your sound to a greater level.

Now you’re probably wondering, well then what else can an audio interface do?


Some audio interfaces come with a panel of effects. These effects directly modify the sound entering the preamp upon recording.

These effects can include but are not limited to reverb, compression, and pan controls. They are usually manipulated by using onboard sliders or knobs, in order to create the desired sound.

Since they are hardware effects, they are not recognized by software effects and therefore can’t be changed.

However, onboard effects can be fantastic for achieving a specific sound while recording or performing live.

Phantom Power

Along your travels of researching and choosing an audio interface, you might come across the phrase phantom power.

You might also see this term if you own a condenser microphone, which is a very popular type of mic for recording vocals.

Phantom power is necessary for condenser mics, and controllable with a switch near the inputs of many but not all audio interfaces.

If you don’t plan to work with condenser microphones, you will not need the added bonus of phantom power, but it is a great option for those who may be working with various types of microphones.


An audio interface is more than a piece of fancy gear in your arsenal. It’s the heart of your studio, the part of the puzzle that makes everything work together nicely.

Shopping for the right hardware that meets your needs can be challenging, with all of its technical language and the variety of options on the market.

Ultimately, the decision is yours, but always bare in mind that there may come a time where you’ll need more capabilities than you think as your sound transforms.

Continue researching and asking questions, and you’ll be sure to find the audio interface that fits best with you.

Michael Ocejo ( Editor-in-chief )

Michael loves audio production. He especially enjoys the technical aspect of making music sound good! Michael also loves spending time with his friends and family and enjoying parties.

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