What Is an Audio Interface and Do You Need One to Record Vocals?

You want to record your own vocals at home, and everywhere you look people say you need an audio interface. But what is that little box, what does it actually do, and do you really need one? Here it is in plain language, no tech talk.

What is an audio interface?

An audio interface is a small device that sits between your mic and your computer. You plug your mic and headphones into it, and it connects to your laptop or PC over USB. Its job is to get your voice into your DAW (Logic Pro, FL Studio, Ableton or any other recording software) clean and at the right level.

What does an audio interface do?

• Boosts your mic (preamp). The signal coming out of a mic is very weak. The preamp in your interface makes it strong enough to record. The gain knob controls how much.
• Converts to digital. Your voice is sound, your computer works with numbers. The interface turns the analog signal into digital, and back again on playback, so you can hear it in your headphones or speakers.
• Phantom power (48V). Condenser mics need power to work. They get it from your interface through the XLR cable. According to Focusrite, dynamic mics usually don't need it.
• Lets you hear yourself without delay. A lot of interfaces have direct monitoring. You hear your voice straight through the interface, without it going through your computer first.
• A headphone output and speaker outputs. So you can listen to your beat and your take through a better connection than your laptop's built-in jack.

Do you need one?

That depends on your mic.

You have an XLR mic: yes

A mic with an XLR connector (the round plug with three pins) can't go straight into your laptop. Think of a Shure SM58, Shure SM7B, Rode NT1 or Audio-Technica AT2020. You need an interface for those, or another device with a mic preamp built in.

You have a USB mic: no

A USB mic already has the preamp and the digital conversion built in. You plug it straight into your computer. For your first recordings, that's totally fine. The downside: you're stuck with that one mic, and you can't easily add a second mic or other gear later.

You record on your phone: not yet

Just starting out and recording on your phone or your laptop's mic? Then that's fine for practicing your flow and your lyrics. When you want your recordings to sound cleaner, an interface with an XLR mic (or a good USB mic) is the next step.

What to look for

• Number of inputs. Recording on your own? An interface with one mic input is enough. Want to record two people at the same time? Get one with two.
• Enough gain. Some dynamic mics put out very little signal. According to Shure, the SM7B needs around 60 dB of gain. Not every entry-level interface gets there easily. More in Shure SM7B too quiet?
• 48V phantom power. If you have a condenser mic, or might get one later, check that the interface has 48V. Most do.
• Direct monitoring. Handy for hearing yourself without delay while you record.
• A good driver. On Windows, use the manufacturer's ASIO driver in your DAW when you can. According to Focusrite, ASIO is made for low latency recording and playback.

Stuck between two popular models? Read Scarlett Solo vs 2i2: which one fits you as a rapper?

How to hook up an audio interface

1. Connect the interface over USB to your computer. Install the manufacturer's driver or software if there is one. On Windows, pick your interface's ASIO driver in your DAW afterwards.
2. Turn 48V off, then connect your mic with an XLR cable. Focusrite recommends switching phantom power off before you plug anything in or out.
3. Turn 48V on if you're using a condenser mic. With a dynamic mic you usually leave it off.
4. Plug in your headphones on the interface's headphone output. Use wired headphones, not Bluetooth.
5. Select the interface as input and output in your DAW's audio settings.
6. Set your gain. Start low, rap your loudest part and slowly turn the gain up until you're nicely in the green, with no red. More on that in distorted recording? How to prevent clipping.

Hearing yourself late in your headphones? Read how to fix latency. Got a Scarlett 2i2? Then how to set up the Scarlett 2i2 for vocals walks you through it step by step.

Will your voice instantly sound like a hit?

Honest answer: no. An interface makes sure your recording comes in clean. How it sounds after that is decided in the mix: EQ, compression, de-esser, auto-tune, reverb and delay. Want to know what order to put those plugins in? Grab the free vocal chain cheat sheet for Logic Pro and FL Studio. Don't want to build it all yourself? There are vocal presets for Logic Pro and FL Studio to use as a starting point, which you then tweak to your own voice.

FAQ

Can I use an XLR mic without an interface?

Not straight into your laptop. You need something that boosts the signal and converts it to digital. That can be an audio interface, but also something like a mixer with USB.

How many inputs do I need?

For one rapper or singer, one mic input is enough. If you record two people at once, or also want to record an instrument, get an interface with two inputs.

Will a more expensive interface make my vocals better?

A little, but less than you'd think. Your mic, your room, your distance from the mic and how you set your gain usually make a much bigger difference.

Can 48V damage my dynamic mic?

According to Focusrite, phantom power normally won't damage a dynamic mic, but it's usually not needed either. Older or vintage ribbon mics can be damaged, so check your mic's manual if you're not sure.

Sources: Focusrite on phantom power and ASIO drivers, and Shure on the SM7B.