Why Do Audio Interfaces Have So Many Outputs?


If you’re new to home recording and just started looking for a good audio interface, you might be thoroughly bamboozled by all the variables that come into play.

One such conundrum might be the existence of a boatload of outputs on the audio interface you’d like to buy. Each plays an important role, but don’t worry—they’re all reasonably easy to grasp.

Audio interfaces have many outputs to allow for versatility. This is useful when you want to do a recording with a band or if the musician you’re recording wants to hear effects while you hear the raw sound quality. You will often have to connect your audio interface to several devices simultaneously.

Read on to learn more about audio interfaces and the outputs you will typically find on them.

Why Do Audio Interfaces Have So Many Outputs?

Table of Contents

I’ll explain each output briefly, so you can understand what they’re used for and why you need them on your audio interface. 

Typical Outputs in an Audio Interface

Different USB audio interfaces will have other output options and connection types, but there are some basic outputs that you can see on most audio interfaces. The number of outputs will vary as well, but we can roughly divide the outputs into seven different types

  • Headphones (or speakers)
  • MIDI
  • Monitor
  • Line 
  • S/PDIF
  • ADAT 
  • Word clock

Now that we’ve got the basic types of outputs, let’s see what they’re used for and what you can do with them when recording. 

Audio Interface – Headphone output

This output is probably the most self-explanatory one on this list.

It sends the sound from your DAW’s master channel to your headphones (or speakers). Having only this output in use when recording is beneficial to avoid feedback and echo, which can be pretty annoying. 

It might be even more helpful if you’re recording your (or somebody else’s) vocals and want to hear precisely how the vocals will sound in the mix.

You can let the vocalist listen to the raw sound or add some effects and create a mix so they can hear what it would sound like after production (sound quality).

In other cases, you might have to work with a self-conscious vocalist who doesn’t like hearing their voice without mixing or editing. In that case, it is advantageous to let them use headphones with some effects added to be more comfortable. 

Having more than one headphone jack output in a home studio is useful. This will allow you and the person you’re recording to listen to different mixes without disturbing each other. Of course, provided you have headphones that are good enough for the task. 

Audio Interface – MIDI

The MIDI output connects the audio interface to any device with a MIDI input.

This can be a synth, module, or something else entirely. Doing this is an easy way to record your performance as MIDI signals so you can process and edit them later.

Having a lag-free MIDI controller is crucial for producers making electronic music production.

Audio Interface – Monitor

This is another very self-explanatory output.

It is probably the most important output on your audio interface, as it’s advisable to do all the mixing on your studio monitors and not on your headphones.

That’s why you might want to listen to yourself on the studio monitors while recording, so you can get a good picture of how the raw audio will sound. 

You usually can choose between connecting the audio interface directly to active studio monitors or connecting it to a preamp and then to passive studio monitors.

Furthermore, on more extensive audio interfaces, there is usually a left and right output, indicating which monitor goes where, while on smaller audio interfaces, you’ll find RCA outputs instead.

Audio Interface – Line (analog signals)

Line outputs can be a very versatile tool, even though it might not be apparent immediately what you can use them for. Some of how you can use them include: 

  • Connecting a different pair of monitors
  • Sending a different mix to someone else
  • Sending audio from the computer to an external processing device

These are just some typical uses, of course. Line outputs can be used for many different things, and you can get creative with them. 

Audio Interface – S/PDIF

S/PDIF is a digital format that stands for Sony/Philips Digital Interface.

It outputs digital audio over short distances in consumer electronics and high-fidelity sound systems. It typically uses a coaxial cable with RCA connectors or an optic fiber cable with TOSLINK connectors. 

Some compressors and preamps have S/PDIF inputs and outputs on them, so you can use this as a means of connecting them to your audio interface.

While this is not the most crucial part of your audio interface, it might come in handy when you have to connect many different devices to your audio interface and use everything you’ve got. 

Audio Interface – ADAT

This is sometimes also referred to as TOS Link or Lightpipe.

Essentially, this output allows you to add extra audio channels if there is a need for that. For example, you can connect a multi-channel mic preamp to your audio interface. 

This can be very useful in a more professional setting, where you’re trying to record many different instruments simultaneously and need every channel you can get. This will likely be unnecessary in a home recording studio since you will record only one or maybe two instruments simultaneously. 

Audio Interface – Word Clock

A word clock signals synchronize other audio devices so they’re not out of sync.

This is another useful output for large studios that simultaneously employ many different pieces of gear. There is much to go wrong in such cases, and it is essential to have equipment that ensures everything runs on time. 

In your bedroom recording studio, you’ll probably not use this very much (or at all), but it’s good to know what it’s for. You never know when your band might decide to start playing ska and employ eight additional musicians. 

Final Thoughts on Audio Interfaces

USB audio interfaces have many different outputs to help you connect them to different pieces of gear. This improves the versatility of the audio interface and makes it easier for you to record, mix and create music production. 

Juan Louder
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Juan Louder

I started SoundStudioMagic to learn how to record my own audiobook at home, and now I'm addicted to all the latest techniques and gear.

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