What’s An Audio Interface...and Do I Need One?
If you’ve started recording with a computer, the learning curve can be daunting—plugging a guitar into a computer is very different from plugging into an amp. So, let’s de-mystify a fundamental element of all computer-based audio: the audio interface.
Computers work with digital data—ones and zeroes. Guitars and microphones generally don’t generate digital data, so you need a way to translate their outputs into something the computer can understand.
There’s also playback. Whether you’re playing back a guitar recording or watching YouTube, the audio in your computer is all about ones and zeroes. Because humans can’t hear ones and zeroes, we also need something that translates that data into audio we can hear over headphones or speakers.
Almost all computers have built-in audio capabilities to cover the translations back and forth between our world and the computer’s world, but they tend to be “consumer grade” for dealing with devices like headset mics, disc players, desktop speakers, and the like. An audio interface is a separate piece of gear that connects to your computer and provides superior audio quality whether recording audio into, or playing audio back from, your computer.
The Audio Interface
Audio interfaces come in all shapes, sizes, and prices, from something tiny that connects to your smart phone to industrial-strength models that can record a symphony orchestra. The majority of affordable audio interfaces connect to a USB port on your computer. They contain a variety of jacks that accept audio for sending to the computer, and can translate computer data into audio for sending to headphones or speakers.
For example, TASCAM’s US-366 interface is a suitable interface for basic recording. It has excellent sound quality, can accept up to four audio inputs (including guitar), and provides three audio output jacks (two for connecting to a stereo amplifier or two powered monitor speakers, and one for stereo headphones).
The US-322A is a less-expensive model that retains the sound quality but has fewer features, while TASCAM’s UH-7000 is engineered for high-end recording studios that require exceptional accuracy and fidelity.
Hooking It Up
Some audio interfaces are called “class compliant”—technical geek jargon for “just plug it in and it should work.” Others require software called a “driver” (provided by the interface’s manufacturer) to communicate with the computer. Your interface will include instructions on how to hook up the interface to your computer.
Once it’s installed and connected, you can choose the interface as an output and/or an input. For the Mac, go to the Apple menu, choose System Preferences, and then click on Sound. Here is where you assign the interface. For example if you want to listen to YouTube on headphones, the US-366 has a headphone jack. Click on the Output tab, select US-366, and now any audio playing back from your Mac will flow out the Mac, into the US-366, and into your headphones.
For Windows 7 go to the Start menu, choose Control Panel, and then click on Sound. Click on the Playback tab, and you’ll see all the available output devices. Click on the audio interface and then click on Set Default. Now audio will play through your audio interface.
For recording from the interface, you can follow a similar procedure when you click on the Recording tab (Windows) or Input tab (Mac). Choosing the right input and getting into recording is beyond the scope of this article...maybe there needs to be a sequel.
Finally, here are two USB interface tips.
· Don’t connect through a USB hub. Connect to a USB port on the computer itself. If you must use a USB hub, use a powered model.
· If your computer doesn’t recognize there’s a USB audio interface connected, with the computer on and booted unplug the USB cable from the interface and plug it back in again. That often alerts the computer that the device is connected.
For further reading:
Les Paul’s Recording Innovations
Quick Tricks for Recording Licks, Riffs and Demos