Audio interface buying guide
Choose the right hub for your home studio
Former Crutchfield staff writer Woody Sherman spent years working as an editor and manager in the video industry at the national level.
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An audio interface links sound or music sources with your computer’s digital audio software. Think of it as the inputs and outputs for the virtual mixing board/recorder inside your computer.
You need five things to begin home recording with a computer:
- Signal sources (an instrument and/or a microphone)
- An audio interface
- A fairly recent computer with plenty of RAM
- Recording software (known as a digital audio workstation, or DAW)
- Monitor speakers and/or headphones
What does the interface do with the signals?
Your interface features two-way conversion — analog-to-digital and, on the way back out of the computer, digital-to-analog, so that your computer and speakers (or headphones) will each get the set of signals it needs. The quality of converters within interfaces does vary, generally in relationship to the price you pay, so be sure to evaluate interface choices with your end goal in mind. A typical podcast doesn’t need pristine processing, but a quality demo for a record company will.
Your interface should also make your analog sources as clean and noise-free as they can be. If you provide a signal to the converter that is too weak or strong, you will incorporate artifacts like noise or clipping that simply can’t be removed once digitized. This means that the same principles that make, say, a home theater receiver desirable are at play here. Better components and circuit design make for more robust signals. And better signals going to your converter make for better sound down stream.
Here's a list of the connectors you might see on a typical interface:
- Headphone jack
- Line inputs for keyboards and other line-level sources. Use ¼" TRS cables for stereo sources.
- Inserts to connect outboard signal processing gear. Use ¼" TRS cables.
- XLR inputs for microphones. With most mic inputs, you'll find an associate +48v switch, which applies "phantom" power to the microphone inputs.
- Line Outputs for your powered monitor speakers. Use ¼" TRS cables.
- MIDI Input and Output for keyboards, drum machines, and other components that have matching connections.
- USB, Firewire or Thunderbolt data ports for connecting your computer.
Instrument input — plug your guitar or bass in here.
The knobs and meters
- Level controls — adjust the signal strength of your microphones and instruments.
- Monitor mix control — turn it all the way to one side, and you hear the signal as it goes into the interface. Turn it all the way to the other, and you hear what's coming out of the computer. In the middle you hear both at equal strength.
- Output level control — volume control for headpphones and monitor speakers.
- Signal level meters — help you set the proper signal strength for your microphones and instruments.
So if you’re shopping interfaces, make sure to inventory your current gear and computer and make sure that the interface you choose can easily integrate with all that you own. Newer computers come equipped with USB 2.0 ports, which is fast enough to record many channels simultaneously. Most audio interfaces are compatible with USB 2.0 or with FireWire, another fast connection that’s found mostly on Macs. If you have an older computer, you can still find interfaces that will work with USB 1.1, which is fast enough to record only one or two channels at a time. Some interfaces are compatible with iPads or with both iPads and computers.
Our product descriptions will give you all the information you’ll need about the connections you’ll need to make. And the accessories tab is a great place to find the cables you’ll need.
The surprising thing about home recording is that starting out doesn’t need to be expensive. Your studio can grow with your personal ambitions. Even a basic interface, adjusted correctly, can get a perfectly good signal into your computer for processing and editing. And there are plenty of solid quality, inexpensive microphones and monitor speakers, too.
Basic home recording setups have enabled thousands of people to generate podcasts, demos, radio dramas, and ambient soundscapes, among other projects. The only real restricting factor is the time you have to spend and the limits of your imagination.