You’re getting ready to dive into creating your own music. You’ve read an entire internet’s worth of information about DAWs, plug-ins, and software instruments. You’re fired up! Then you read a little more on studio equipment and come across the term audio interface. Something else to buy? Maybe, maybe not. Read on to get the low down…

So, what is an audio interface?

In the simplest terms, an audio interface is a device that connects to your computer and enables you to get audio in and out of it. Every computer has an audio interface (sometimes referred to as a soundcard); that’s how you hear a ding every time a cute dog video gets posted on YouTube. It’s also how people can listen to you when you’re talking on a Zoom call – through the mic that captures the sound. But the soundcard inside your computer wasn’t designed for recording high-quality audio, and thus began the rise of the external audio interface.

What’s in an audio interface?

A quick search for audio interfaces will show you just how many varieties are on the market, all with different specs and configurations. Confusing, right? Luckily, they are all essentially born of the same mold.

Inputs & Outputs:

Inputs will allow you to record using ¼ inch instrument cables (for instruments) and XLR cables (for microphones). How many inputs your audio interface has will dictate how many tracks you can record simultaneously.

For example, a singer-songwriter may want to record a vocal take and an acoustic guitar simultaneously. So a simple two-in/two-out audio interface will be sufficient for the project. Someone who wants to record a fully mic’d drum set-up for remote session work will need more inputs.

Outputs will allow you to connect external speakers, ideally studio monitors, with a flat response to paint an accurate picture of how your music sounds. Some audio interfaces have multiple output options, for instance, when mixing in surround sound or sending audio to different destinations simultaneously. Think about how many outputs you need when choosing an audio interface.

Many manufacturers offer different versions of the same type of audio interface. Most of the time, the differences depend on the number of inputs and outputs each one provides.

Inputs and outputs will each have separate controls for their respective levels.

Mic Preamps

Welcome to the audio science laboratory part. This post isn’t the place to go into a lot of detail. All you need to know is that a mic preamp contains circuits that boost a low-level mic or instrument to get it up to line level. The preamp quality affects the quality of the audio you record. Remember the adage ‘garbage in, garbage out?’ Some audio interfaces boast ultra-high quality mic preamps and come with a price tag to match. Luckily for your bank account, there is a range of affordable audio interface options with great preamps. One point to team technology.

Audio Converters

Continuing our foray into the audio science laboratory… You’ll need to get your audio from the analog world into the digital realm. Your audio interface will convert the signal into something your computer can read by turning it into thousands of tiny samples during this process. The same process occurs the other way; digital audio is converted back to an analog signal and piped to your speakers.

This is where sample rates come into play; the higher the sample rate, the better the quality of the audio. And so, the better quality your converters are, the better quality your audio recordings will be.

As technology marches ever-forward, so does the capacity for audio interfaces to support increasingly higher sample rates. For a small project studio, an audio interface that supports up to 48kHz will do the job just fine.

Monitoring

When you’re recording, you’ll want to monitor what’s happening, and every audio interface will have a dedicated section for precisely that. The simplest will just be a volume knob for the cue output (generally, you’ll be using headphones) and a knob to control the mix between the input and output. Say, for instance, you’re recording a vocalist topline to a track you’ve created; the vocalist will want a blend of their voice as well as the music. The mix knob will control just that.

Generally, the higher up the price bracket you go, the more monitoring options you’ll have.

MIDI Connection

Some audio interfaces will also offer In/Out connection to external MIDI devices, such as a keyboard or sound module. This connection can help you run external MIDI devices in your set-up if you don’t have enough ports on your computer to handle a dedicated MIDI interface.

Insert Connections

The ability to use insert effects on an incoming audio signal can assist with tasks like adding a little light compression as you record a vocal. Some audio interfaces offer this option.

Types of audio interfaces

Audio interfaces connect with your computer the same way other peripherals do; via ports on your computer. Whether you choose a USB, Firewire or Thunderbolt audio interface will depend on your computer’s ports and how you’ll use it. If you’re planning on recording multiple sources simultaneously (a fully mic’d drum kit, for example), you’ll want to choose a connector with higher bandwidth, such as Firewire or Thunderbolt. If it’s just you crooning away to your masterpiece, then USB will be ample.

Do I need an audio interface?

The answer to this question varies, depending on how you make music, and to some extent, what kind of music you make. If, for example, you work exclusively in EDM, and everything you create is purely sample and software instrument-driven (and you’re comfortable working only with headphones), then the built-in audio interface that came with your computer will suffice.

However, if you’re a singer-songwriter and plan to record vocals using a microphone, or you want to dust off your trusty old Fender Strat to shred out a riff, you’ll need a way to get that sound into your computer. If you want to record both at the same time, you’ll need two inputs.

Similarly, if you want to save your ears from fatigue or annoy the neighbors by hooking up some external speakers, you’ll need a way to get sound out of the digital realm and into wall-shaking territory.

Bring on the audio interface.

Great, but which audio interface should I buy?

The market has audio interfaces to match every budget, from sub-$100 to multiple thousands of your hard-earned cash. Be realistic about what you’re planning to do audio-wise. Do you need eight In/Out if it’s just you and your uke when a two In/Out will do? On the other hand, if you’re pretty sure that next year you’ll be recording some live sessions with your Cajon/flute/sitar jam trio, then a four In/Out will allow room for growth.

The other factor to bear in mind is progress. Ports become obsolete, operating systems move on, and technology improves the performance of devices. Expect to get around 5-7 years of use from your audio interface before the incompatibility gremlins come knocking.

Figure out what you need from an audio interface, set your budget, and do your research.
Happy recording!