What is an Audio Interface?

by ReverbLxnd in Mixing

What is an audio interface?

What is an Audio Interface Used For?

You connect your audio interface to computer using a connection interface (usually USB or Thunderbolt).

Typically, an audio interface has mic and line-level inputs and controls at the front, and line-level outputs and MIDI (inputs and outputs) at the back.

The inputs are suitable for connecting input devices such as mics, instruments such as keyboards, guitars, your synths and digital instruments and a raft of other audio devices so you can make all sorts of high quality recordings.

During a recording, you record an analog signal from your mics or instruments. The audio interface is used for analog to digital conversion (ADC), to an audio stream which can then be stored and edited on your computer.

You use mic inputs if you want to record your mics.

You use line-level inputs if you want to record your keyboards, mixers, multiple inputs and so on.

You can also switch to instruments and record, say, a guitar, directly.

During playback, the reverse happens. The audio interface is used to convert the digital stream to analog (DAC) so you can actually hear what you’ve recorded.

Typically, you will have two volume controls so you can control the volume of your limiters seperately to that of your headphones.

You can switch the headphones between two different sources and queue playback.

You can direct monitor, which perhaps the coolest feature of an audio interface.

Direct monitoring means you can record one track on top of another and hear what you are recording in real time, without latency.

There are many other features beyond these such as switching from direct monitor to stereo mono, providing phantom power to a condensor mic.

Do I need an Audio Interface?

Both a audio interface will include phantom power. This is one of the main reasons people buy audio interfaces in a home studio. Condensor mics need phantom power to work. In order to have a home studio, a condensor mic is a must.

That is one of the main reasons an audio interface is so important.

An audio interface is the essential if you want to make high quality recordings on your computer.

Besides what I’ve mentioned above—

#1 — Yes. To Get High Quality Recordings (Mic Input)

If you want a high quality recordings of yourself playing a guitar or piano or recording high quality vocals, for instance, an audio interface comes highly recommended.

Whether you run a podcast or are a vocalist, or doing any audio work really, an audio interface is a central device in a home recording studio. It is a hub of sorts.

With audio interface, you get very high quality recordings.

An audio interface has builtin preamps so you can use gain controls on your inputs to get just the right amplitude for good quality recordings.

#2 — Yes. To Control Virtual Instruments with a MIDI Keyboard, Use MIDI Editing Software, and Playback MIDI (Line-level Inputs)

An audio interface with MIDI inputs and outputs allows you to use your MIDI keyboard as a controller to control virtual instruments on your computer, use MIDI editing software or playback your MIDI instruments.

Using an audio interface, you get very high playback quality of your recordings. This is obviously very important for monitoring your recordings.

What’s the Best Audio Interface?

When it comes to building your home studio, this is perhaps the most important decision.

One thing to keep in mind is that it does not matter what how much you spend an audio interfaces, you can get professional results, with the right skills and talent.

In fact, technology has improved so much that budget audio interfaces today rival expensive equipment. And like I always say, musicianship comes before equipment.

What to Look For in Audio Interfaces (5 Essential Things)

That said, here are some things you need to look for when selecting audio interfaces.

#1 — What Computer Do You Have

On one hand different computers come with different audio connections, on the other, different audio interfaces comes with different computer connections.

There is ThunderBolt/USB-C connection which is mostly seen on most laptops, Apple Macs. Actually, there are two modern types of Thunderbolt — the older Thunderbolt 2 and Thunderbolt 3 (also known as USB-C on Macs).

Thunderbolt carries both Video and Data.

There is also USB 2.0 and the newer USB 3.0. USB 2.0 have a black tip, for instance, whereas USB 3.0 cables have a blue tip and sometimes come with a “Super Speed” or SS label.

Of course there are many more other options that just these two.

What you need to consider carefully is what kind of connections your computer has.

If it has a Thunderbolt, that allows you to have a Thunderbolt interface. If it only has USB then you only have a USB interface. If it has both, now you can choose.

#2 — How Many Inputs Does the Audio Interface Support

The second most important thing to look at is the number of simultaneous inputs the audio interface supports.

If you’ve read what is overdubbing, you already know you don’t 10 inputs to record 10 tracks, if you haven’t read that article, go have a look.

The idea here is that even with overdubbing, it’s still important to know how many inputs you will need at any given time in your recording process (to record simultaneously).

By way of example, if you are a vocalist and you also play guitar, you’ll only need two simultaneous inputs to record — one for your vocals, one for your guitar.

If, on the other hand, you setting up a drum mic kit for your home recording (basically multitrack drums), that’s already 4 mics on the drums kit alone — kick snare, and overheads.

This scales up pretty fast.

You have to consider beforehand how many inputs you will need to record simultaneously.

That’s what you need to look for when choosing an audio interface.

You can get an interface that allows 8 inputs for instance, but only 4 of which are mic and the other 4 are line level inputs. That can be severely limiting if you did not consider the inputs carefully beforehand.

Make sure you don’t only check the channel count, but the number of preamps too. That’s the quickest way of truly knowing how many mics you can plug into the audio interface.

#3 — What are Your Future Needs

You need to have your future needs when choosing an audio interface.

Audio equipment can be very pricey sometimes and our needs will always keep changing.

In most cases it is worth considering an audio interface that has not only what you need now but further down the line.

If you only need two inputs today, say, you’re only recording vocals and your guitar today, if you get an audio interface with two inputs, that means you can never record more than two things at a time in the future.

You want equipment that accomodates some expansion, at the very least. This is perhaps the only reason to buy something that’s a little bit more pricey.

#4 — What is the User Experience with the Audio Interface and Software

This is a pretty essential one for every equipment purchase.

You need to find out what the experience is of other people with the audio interface or software you are about to choose.

This is where things such as online forums and reviews comes into play.

Most audio interfaces come with a software component that controls an aspect of recording on with that interface.

You need to look at what people are saying about the software, builtin effects, or controls that comes with your audio interface. This software is a significant going to be part of your workflow.

If the audio interface is feature-perfect but the software is pretty much unusable , well, there you have it.

#5 — How Many Outputs Does the Audio Interface Have

This is much less important nowadays that it used but you’ll still get the occasional audio interface with one output.

This is a ridiculous!

If you ever intend to record a band (more than one person, really) an audio interface with a single mic output is a dud.

If you just want to record yourself, that’s all you need. But anything beyond that, you’ll have to start looking for other options.

Does an Audio Interface Affect Sound Quality?

I was listening to Graham (Recording Revolution) the other day where he was saying that “today there is no more debate about the quality of audio interfaces”, and I find myself agreeing with him.

There are tons of premium audio equipment at different price points in the market today. Perhaps, there always will be. But there are tons of affordable equipment too, made by reputable companies no less.

There is no shortage of professional sounding stuff made on budget equipment today.

So, does an audio interface affect sound quality?

There are a lot of recordings done on very affordable audio interfaces that rival anything by the big studio. This is because the musicianship is just better.

By musicianship here, we are talking about better skill (technical skill, songwriting, you name it), more talent, more performance — generally, things that have little to do with equipment.

The audio interfaces in the affordable range today, used skillfully, should sound good enough that quality isn’t necessarily so much of a concern anymore.

You can and should get professional results on a budget interface.

In Conclusion

You should now have a good idea of what an audio interface is.

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I've been a musician and brought in my stuff for mixing and mastering, I've been my own producer where I wrote, recorded, mixed and sold my own stuff. Now, I'm *mostly* an audio engineer, where I only record and mix for clients. I'm currently based in Berlin, Germany, where I operate ReverbLand out of. Got a question? DM me on Instagram or Twitter @reverblxnd everywhere, or shoot me an email reverblxnd@reverbland.com. I'd love to hear from you.

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