What Is an Audio Interface?

An audio interface is an external sound management device. It allows users to connect various types of audio hardware together, and route the signal to an output – usually through USB into a computer these days. Depending on its design, it can incorporate anywhere from 1 to over 20 audio inputs, as well as similar numbers of outputs.

This device is what allows musicians to record their various instruments, as well as DJs to host a music party. It is also used by businesses, colleges, YouTubers, live streamers, and many other fields that require the use of audio recording equipment.

It also serves as an ADC, or Analog-to-Digital Converter, and tends to have very good shielding around the analog inputs and outputs to limit the amount of electromagnetic interference, which can result in hissing in your signal.

Do you Need an Audio Interface?

Depending on what you need to accomplish, you may or may not need a dedicated audio interface. Some modern approaches to microphone design utilize USB and plug directly into a computer. Make no mistake though. The USB microphone still utilizes an audio interface – a barebones design within the housing of the microphone itself. You can’t get around needing some form of interface, but you can omit an external audio interface if it is built into the microphone itself.

For users who need to record on the go – if you have a laptop, then a USB microphone can do the job. However, carrying a laptop into nature isn’t always the easiest thing to do, as they tend to be fairly fragile. So if you plan on recording nature sounds, then you would be better served to get a recorder – a purpose-built audio interface that has basic recording functionality.

However, for those of you who are looking to hook your guitar or other musical instruments into a computer, you’ll need an audio interface for sure, unless the instrument has one built-in, like the aforementioned USB microphones.

What Kind of Inputs Can Be Found On an Audio Interface?

There are five types of inputs that are typically found on modern audio interfaces:

• XLR, or External Line Return
• 1/4″ Stereo Jack
• AUX Cable \ 3.5mm
• USB
• and Midi

Out of those four, XLR and 1/4″ are the two most commonly used for higher-end Condenser and Dynamic microphones. Midi is designed specifically for musical instruments, and the 3.5mm connector is basically a shrunken down stereo jack.

The USB is a bit of a special case, as it is both an input route, a power supplier, and an output route. This is possible because it is the other end of the analog to digital conversion.

What Outputs Can Be Found On an Audio Interface?

There are a wide variety of audio interface outputs utilized:

• RCA, or composite audio
• XLR
• 1/4″
• USB
• Midi
• 3.5mm
• Banana plugs
• Firewire
• Conduits
• and More

Each Audio interface may have some of these, but you’ll never find one with all of them. This is why it is important to plan out your needs for audio.

What Features Matter the Most for an Audio Interface?

The most important feature of any audio interface is its input and output capabilities. If it lacks the necessary quantity of IO for your needs, then it is unsuitable for you. Barring that, the feature to look out for regarding quality is the preamps that are used in the device.

There are a wide variety of preamps out there, and choosing an interface that is capable of driving the microphone you intend to use is important. One of the more popular microphones out there, the Shure SM7B, is notoriously gain-hungry, and many cheaper preamp designs are unable to adequately drive that microphone. The video above helps demonstrate what happens when you push the limits of the preamps.

It isn’t the end of the world if your interface is unable to drive your microphone, as there are inline amplifiers that you could buy to boost the gain of the signal to appropriate levels. However, this is an extra cost, one that can be avoided if you buy an interface with sufficient output in the first place.

Check out this article by Audient that dives in a little bit deeper on this subject.

One thing I will mention, for the sake of streamers, is that it does not matter what Khz the interface supports, as long as it is at least 48 Khz, because most broadcasting programs do not openly support higher than that. You don’t want to be mixing audio frequencies, especially unsupported frequencies on devices to avoid audio syncing issues.

The Audio Interface That I Recommend for Streamers

I have been using the Behringer UMC204HD Audio Interface for the better part of three years now. It has served my needs nearly flawlessly, with only a few hiccups along the way. It has more than enough IO for most streamers, and will even allow you to set up a Stereo Microphone setup in case you intend to do ASMR streams.

But the most impressive feature of this little $100 interface is that it has a mix knob. This allows you to directly monitor your microphone, as well as listen to devices it is attached to via USB simultaneously. This is super important for streamers who utilize noise-canceling headphones, like my Beyerdynamic DT 770 Pros. By the way, it also supports the use of high-quality mid-grade audiophile headphones, up to 300 ohms of resistance.

This little interface does struggle with low-output microphones like the SM7B though, so be wary about that. I had to crank the gain knob to 100% to be able to hear some no-brand dynamic microphone I found at the thrift store for $15, causing a fair amount of pre-amp noise in the signal. Even so, It has proven to be an invaluable tool, and I see no reason to upgrade it any time soon.

I hope this article was helpful to you. If there is anything you think I missed, please let me know in the comments down below. I want to provide the most helpful and accurate information possible, and your feedback is invaluable for this endeavor.