What is an Audio Interface? Explained Clearly

What is an Audio Interface

If you’re new to the world of music production and want to record music at home. You need to find a way to get audio into your computer. How do you do that? Well, firstly you need audio software, this is known as a DAW and you can read all about that in my article What is a DAW? Secondly, you need an audio interface. But what is an audio interface? What is an audio interface used for? Do you need one? And which type do you need?

I’m glad you asked because the answer is not so straightforward. Like most audio gear, there are various options to choose from and some technical jargon to understand. If only there was someone you could depend on to explain it clearly to you. Someone who writes easy to understand explanations and designs clear diagrams… Oh wait, that’s me. Lucky you! I wish I had someone to explain it all to me when I began.

It’s Normal to be Confused

I remember being in the exact boat as you. In fact, when I got my first audio interface (a Digidesign rack 002) I was completely baffled about what all the buttons did, and what the purpose of all of the inputs/outputs were. I approached my flatmate who was studying music to ask for help, but even he was perplexed by some of the technical names written on the interface. That’s why I created this website and my YouTube channel, to help you navigate through this new world.

In this article I’m going to explain exactly what an audio interface is, it’s functions, the different types, and the most complex topic, the inputs and outputs. I can guarantee that after reading this article you will have a clear understanding of audio interfaces, and you can make a purchase without any more confusion. Let’s begin.


Audio Interface Overview

What is an audio interface? Simply put an audio interface is a piece of hardware that allows you to get audio into your computer, tablet or iPad. You can’t plug in a microphone cable (XLR) or an instrument cable (TRS/TS) directly into your computer, so you need an in-between device to do the work for you. Want to read all about audio cables? Check out my article explaining audio cable connector types. You also need an audio interface to get audio out of your computer so it can be heard through headphones or studio monitors (speakers). 

Analog to Digital Conversion
An audio interface converts an analog signal (such as a singer singing into a microphone) to a digital one.
Digital to Analog Conversion
An audio interface also converts a digital signal (such as an audio file) to an analog signal.

Audio Interface Buttons and Controls

Before we go into inputs and outputs, let’s examine some typical controls and functions you would find on an audio interface.

Audio Interface Buttons and Controls

Audio signals coming from an instrument or microphone can often be too low, so we use the gain knobs to turn up their volume. If the the volume it too loud, some audio interfaces have some LEDs or a meter to tell you if the signal is too hot. In that case you should turn the gain knob down.

If your audio signal is still too loud, you can press the PAD button, which reduces the volume by a fixed amount, it’s quite a common feature an audio interface. Microphones require more power than instruments so all audio interfaces have a phantom power button which delivers 48V of power to a microphone. Finally, you have a volume control for your studio speakers and headphones. Simple so far, right? Well, brace yourself but next were going to talk about inputs and outputs which can get a little bit confusing.


Audio Interface Inputs and Ouputs

Inputs allow you to send or get audio into your audio interface. So, the more inputs you have, the more instruments you can record. If you’re a solo musician like an electronic music creator, singer, or guitar player, 1-2 inputs will suit your needs. If you play in, or want to record a small group with a mix of electric/acoustic instruments, 4-8 may get you by. However, if you will be recording a full band at once, you’re going to need 20+, bearing in mind it’s common practice to use at least 8 microphones on a drum kit; it depends on your needs. Let’s break down the basic types first. MIDI

Inputs

  • Mic Input – Allows you to connect and record a microphone directly into your audio interface.
  • Instrument Input – For connecting and recording low signal (known as instrument level) instruments like a guitar or bass.
  • Line Inputs – Enables you to record hot signal (known as line level) instruments like a synthesiser or electric piano.
  • MIDI Input – Gives you the option to connect and record a MIDI device, such as a MIDI controller, or MIDI keyboard. However, note that most MIDI keyboards can be connected to your computer directly by USB these days.

Audio Interface Inputs and Outputs

Outputs

Outputs allow you to send audio out of your audio interface to some headphones or studio monitors so you can listen to your music. You may also want to send your audio to some external hardware such as an effects unit, compressor, limiter, EQ unit, and so on.

  • Headphone Output – Simple enough, lets you plug in and send audio to your headphones.
  • Monitor Output – Allows you to connect and send audio to your monitors (studio speakers).
  • Line Output – Lets you connect and send audio to your studio monitors, or external hardware.
  • MIDI Output – Enables you to send MIDI data from your DAW to a MIDI device, for example to a sequencer or synthesiser.
 

Additional Inputs and Outputs

On more expensive audio interfaces, you can find some additional inputs and outputs that give you more connectivity options. These inputs and outputs simply allow you to receive or send audio to, and from other types of external hardware.

  • SPDIF – Can send or receive two channels of audio. You could use it to connect CD or DVD players, game consoles, effect units, and some synthesisers also use SPDIF.
  • Optical (ADAT) – Can send or receive eight channels of audio, so optical is more versatile than SPDIF. You could use it connect a mixer, PA system, or you could connect another audio interface to your original one, giving you more inputs and outputs.
  • World Clock – When you connect one or more audio interface together, they can become out of sync which cases clipping, noise, and distortion. We use the world clock to make one ensure that they are synchronised correctly, working in perfect harmony together. Now everybody is happy.

Phew! I’m glad we got through all of that… I know it can be a lot to take in when you’re just beginning. I remember when I started out, I bought a very old Digi 002 rack from eBay. When it arrived and I had absolutely no idea about what all of the inputs/outputs mean. So, don’t feel bad if it’s a lot of information to take in.


Audio Interface Connection Types

Audio interfaces can be connected to your computer via various cables types, which process data at different speeds. There are four common types used for audio interfaces.

Audio Interface Connection Types•  USB – Offers the slowest transfer data rate, typically found on budget interfaces for home studio use. 

•  Firewire – Faster than USB, found on more expensive home studio devices. Nowadays, these are becoming less popular, due to Thunderbolt.

•  Thunderbolt – Much faster than both USB and Firewire, becoming more popular on semi-pro interfaces.

•  PCIE – Extremely fast data-transfer, used for professional interfaces when high processing power is required.

Despite USB being the slowest, it’s more than fast enough for the majority of home studios. Regardless of which connection type you choose, make sure your computer is compatible.


Compatibility

Mac Logo and Windows LogoWith regards to compatibility, most audio interfaces are compatible with Mac and Windows, and most, if not all are compatible with every DAW available. So, you don’t have to worry there, although it’s good to always double check, just in case.

Something else you may look for, is if the audio interfaces’ DAW can be used with an iPad, iPhone, or tablet. Some offer that ability, giving you the option to connect multiple devices at once, making your workflow much faster.


Do audio interfaces include any software?

Focusrite Scarlett Series Software BundleIf you’re just starting out in the world of recording music, lucky you, you’ve come at a great time. It’s never been easier to create, record, and produce music at home. As audio technology has developed, products have become more advanced and budget friendly. As soon as a company ups their game and offers more, others have to compete, or at least match what’s on offer.

A lot of audio interfaces today come with software bundles, this can include DAWs, plug-ins such as EQs, compressors, limiters, reverbs, modulation effects, amps, virtual instruments, and more. This puts you in a brilliant position to get recording right away, and producing professional sounding music, providing you make good use of the resources available. 


Audio Interface Form Factors

This geeky jargon simply refers to the size and shape of the interface, there are two types to consider.

Desktop Audio Interface and Rackmount Audio Interface•  Desktop Interfaces – Smaller and able to sit on your desk, next to your computer.

•  Rackmount Interfaces – Larger and mounted on a rack unit. However, you don’t have to mount them on anything. You can still just place them on top of a desk. That’s exactly what I do with mine, but shhhh don’t tell anyone…

If you’re just starting out, or need something minimal, then I’d suggest going for a desktop interface because they’re simple and easy to use.

If you want something more advanced, versatile, and flexible with regards to signal routing and inputs/outputs, then consider a rack mounted interface.


How much does an audio interface cost?

The biggest difference between low priced audio interfaces, compared to high priced ones, is how many inputs/outputs and connectivity options are available, plus the recording quality. Expensive audio interfaces have better preamps and components, resulting in better audio quality.

Man in Home Recording StudioFor beginners, home studio owners and budget studios, a moderately priced audio interface will serve you perfectly well. If you’re running a professional studio, recording full bands, charging clients high sums of money, then you should indeed invest in an expensive higher quality audio interface, or even better, a mixing desk.

It’s important to remember that gear isn’t everything! Producing great music starts with a great performance. Recording equipment has come a looooong way in the past few decades. Budget audio equipment is more than capable of producing professional sounding music, especially with the tonne of plug-ins that are available to enhance your mixes.


What audio interface should you buy?

I hope that after reading this article you now have a clear idea about what an audio interface is, what an audio interface is for, what it does, and how it works. If you’re a podcaster, live streamer, musician, or music producer you need an audio interface to record professional sounding audio. Trying to choose the right one for you is not easy, as there are so many options to pick from. Ultimately, one of the most important factors for you is likely to be price.

To help you out I’ve written an article listing the best audio interfaces from low to high price, detailing what software is included, and the inputs and outputs available for each. Don’t overthink too much which one to purchase. They all serve the same basic function of getting audio in your computer. As long as you know how many inputs and outputs you need, then any from my list will serve you well, as they all have a renowned reputation for longevity, reliability, and quality.

New to audio production and what to know what other equipment you need? Check out my article here.

I hope you found this guide helpful. If you have any comments, or questions, feel free to write them below.

Chris

chrissoundlab.com

27 thoughts on “What is an Audio Interface? Explained Clearly”

  1. this is fascinating and really so cute i am going to share it with my friends as soon as possible. this is the first time for me knowing about Audio Interface like Buttons and Controls and Additional Inputs and Outputs and how to use them.. menawhile thank you for sharing this article  and your tips as well.    regards ismail

    Reply
  2. Hi Chris,

    Very detailed and well written article about audio interface. Easy to understand and to the point. I must say, even if a person is new in this field (as me), can still do a great job using your explanation and pictures. You also clarified a few terms I’ve heard so far, but I didn’t know what they meant and what they were used for.

    You mentioned that the audio interface can be used to record music, podcasts, etc. I guess I can use it just as well to record guided meditation sessions, right? A desktop interface would be enough for me?

    I will also read more carefully the article about audio equipment to see your recommendations for microphones. Thank you very much for sharing this information. For sure I will come back for new updates. Keep up the good work.👍

    Reply
  3. Hey Chris. Well done on taking a complex topic and making it easy to follow. I worked as a videographer for a couple years so had to deal a lot with sound and audio. It was the toughest area for me as with audio and sound you can’t see what the problem is, you have to hear it. So, it can get pretty tricky.  

    I enjoyed the way you explained audio interfaces in your article, whilst making it easy to follow.

    Thank you.

    Sammy

    Reply
    • Hi Sammy, I totally agree, audio can be an incredibly complex matter. That’s why I try to write my articles as clearly as possible for beginners. I’m really glad that you found it helpful and easy to follow.

      Reply
  4. Thank you for assisting me on what audio interface I should buy. I was honestly a bit confused so I wanted to get things a bit out of the way and clearly understand what I was getting and what I really need. Some of the bit more technical stuf your explained also came in handy. Thank you very much! 

    Reply
  5. Thank you for the informative article on audio interface. The information is not only for music producers, I have been thinking about setting up a home studio for sometime, me and the kids are always recording one thing or the other, This information will come in very handy when we finally set it up.

    Reply
    • Oh, that’s really cool Bogadi! Why not? You can easily set up a mini student at home on a budget and it sounds like you and your kids will enjoy it!

      Reply
  6. Hi, Chris!

    It is indeed explained clearly! At first, I felt a bit lost among so many inputs and outputs but in the end, it is relatively easy to do. Your presentation on the topic is so thorough and easy to follow that I could start today looking for the best to form a rock band! (lol)

    I became a fan of your website and I’ll definitely come back for further news.

    Thank you so much and keep safe!

    Reply
  7. Really awesome information!  I was looking up equipment for my son so he could do something similar with his guitar.  Not sure if this is exactly what he was looking for or not, but I am going to share this post with him.  His birthday is coming up and I do need some ideas, as he always tells me he doesn’t want anything.

    Reply
  8. Hi Chris – The site is very well organized and has a friendly tone.  

    As someone new to audiobook and Adobe Audition, I have a lot of questions about the overlap in gear?  I was able to connect a good microphone to my pc, use sound filtering to remove a lot of noise, and have been learning from Audacity and now Audition software.  I’d be interested in topics or posts you might have along those lines?

    I appreciated the work, nice job!

    Steve

    Reply
    • Hi Steve, yea sure. I don’t have any articles about Audacity or Audition yet, but you can always email me if you have any specific questions.

      Reply
  9. I recently bought a condenser mic for my studio. I’m new to music, and in search of an audio interface and I came across your awesome post. You’ve done a really good job and it helped me a ton. Thanks for your blog post.

    Reply
  10. Wow, this is a really thorough post for anyone looking to record their music. I like how you broke it all down and added the lessons that you learned along the way. This information could save a would-be self made recording artist a lot of time and money and frustration.

    Reply
  11. wow this is a very helpful information and i really want to commend you for sharing this with us.i am a lover of music and i have been able to write songs but have not visited the studio but with the help of this information i now have idea about the audio interface and how i can be able to add audio into my computer thanks for this helpful info

    Reply
  12. What a fantastic audio article. It was so simple to understand and I really enjoyed reading it and working out the pictures. As a musician I’ve always wanted to do recording but was scared off by the jargon and now I really understand it. You’re amazing. Thanks so much, I will be bookmarking this to refer to when I head off to buy my first audio interface.

    Reply
  13. Hello Chris,

    first of all, i would like to thank you for your article about the Audio interface.
    I am quite fresh in the world of production and sound so I hope you will be able to answer my simple question.

    I have looked on the internet but I couldn’t get any documents or articles that can help me to understand.

    i am thinking to purchase an audio interface and connect to the software, get the sound from the microphone, and send it to the PA system.

    My question is, can you connect the audio interface and connect it to the PA system.

    Thanks and looking forward to get the reply from you.

    Reply
    • Hi Huan. I’m glad that my article helped you. Yes, you can do that with no issues at all. You’d simply use the audio interface line outputs and connect them to a PA system. That way the audio from you audio interface will come out of the PA speakers. If you need an answer in any more detail please let me know.

      Reply

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