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What is an audio interface?

An audio interface is an external device that serves as a bridge to connect your computer to other equipment. For our purposes, the interface converts the digital audio from MainStage and converts it to analog for a sound system or speakers. There are several reasons to use an audio interface instead of your computer’s headphone jack.

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Advantages of using an audio interface

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Higher quality output

The difference is subtle, but as a device built specifically for handling audio, an interface will often provide higher audio quality than your computer alone.

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Better physical connection

Headphone jacks can be finicky. If you accidentally bump an audio cable plugged into a headphone jack, it might make a loud buzzing noise or pop. An audio interface connects to your computer with a stronger USB plug, so it’s less likely to buzz or drop the connection if your computer is moved.

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Signal strength

Audio interfaces usually have a wider dynamic range than your computer’s headphone jack. An interface can send an audio signal at a louder level. Additionally, you don’t have to worry about keeping your computer’s volume at the same level for every performance.

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Low latency

Latency is essentially the time between when you press a note and when the note actually sounds, usually a number of milliseconds. The more the latency increases, the more this delay becomes noticeable to the player. Since the audio interface shares the processing work, it’s less strain on your computer and helps to keep the latency low.

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MIDI handling

An interface can also handle sending MIDI from the keyboard to your computer, which is generally more reliable than directly using USB to send MIDI.

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Multiple outputs

Larger interfaces can route the audio output from MainStage to more than just two channels. This is helpful, for example, if your keyboard part includes sound effects and your sound designer wants to mix them separately from the instrumental keyboard sounds.

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What kind of audio interface do I need?

Even an inexpensive audio interface is better than using your computer’s headphone jack. An interface can be as cheap as around $100 or as expensive as several thousand dollars. A more expensive interface will generally have higher quality, more inputs/outputs, and more features. In most situations, an inexpensive interface will be perfectly fine.

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MIDI input and output

In addition to audio, we strongly recommend using your audio interface to handle MIDI. Thus, it is important to choose an audio interface that includes MIDI ports.

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Number of channels

Realistically, two output channels (stereo left and right) are perfectly fine for most situations. If you are able to afford it, we recommend choosing an interface with more channels because you will have additional routing and mixing flexibility (e.g., sound effects triggered by the keyboard).

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