An audio interface is, quite simply, what you need to get sound in and out of your computer. If you want to make a good quality recording of your voice or any instrument and hear the results so that you can mix and master your recordings, you will need an audio interface. If that has answered your question, then you can hop straight to our post that lists all the most popular audio interfaces right now.
You can make basic recordings with any modern computer, laptop or tablet as they all come with a built in sound card. You can improve the sound of your recordings to some extent, especially on phones and tablets, with a better microphone. However to really make a professional recording you will need an audio interface or a better sound card.
Below is some detailed info about what is an audio interface, and what it is used for, then we also have a detailed post on how to choose the best audio interface for you.
I’ve got a USB Mic, do I need an interface as well?
Aha, this is such a common question and a source of much confusion! You tend to think of an audio interface as a box with various inputs for mics, instruments etc and outputs for speakers and headphones. But there are lots of other devices that are effectively “audio interfaces” too. A USB mic is a classic example.
Effectively a USB microphone is a mic that contains an audio interface. This means you simply plug the mic’s USB lead into a USB port and it will work. You don’t need any other equipment. It may just be a recording mic or it may also have a headphone output too and be a complete input and output device.
There are other USB audio adapters that fit into this category. They work on their own and don’t need any other equipment. So you can get an XLR-USB cable to connect a mic up to your computer, and also guitar-USB, line out to USB etc etc.
Is an audio interface the same as a sound card?
Essentially yes, a sound card and an audio interface do the same basic job. To get sound in and out of your laptop, pc, mac, tablet so that you can process and edit it you need something that turns the sound into a digital signal and back again. That’s what the soundcard or interface does.
Basically, an audio interface is an external sound card, perfect for laptops and tablets, and now widely used by people with desktop computers too. Gone are the days when the only way to improve your recordings was to fit a new sound card inside your machine.
You can almost certainly already record and playback with your laptop, pc, mac or tablet, but buying an audio interface will take you one step towards sounding more professional. An audio interface is the equipment that sits at the heart of any home recording studio.
So what is the purpose of an audio interface?
Ease of use and high quality recording – one of the main advantages of an audio interface over on-board sound cards is that, because of the greater physical size and easier accessibility, a wider range of input types can be built into the unit. So, for instance, ¼” jack guitar inputs can be included, as can full XLR microphone inputs, meaning that the device can be capable of connecting to wide range of professional recording equipment. In addition to this, audio interfaces generally feature higher quality audio quality than standard on-board sound cards. Many also have MIDI if you want to connect a keyboard controller too.
How do I connect an audio interface to my computer?
Most audio interfaces are USB soundcards. As long as you have an available USB port or a USB adapter in the case of a tablet then you can connect one up (you will need to check the hardware specs to make sure it will be compatible). So USB audio interfaces are the most common and you should find one that will suit you. There are also a growing number of thunderbolt audio interfaces, and you can still buy firewire too. Thunderbolt and firewire have the advantage of being faster, but tend to be pricier. And of course you must have one of those ports available. As USB has got faster, most people with home recording studios find a USB recording interface is perfect for them.
What is the best external soundcard or audio interface for music production?
We have a sister article which looks in depth at how to decide which is the best interface for you. There is no one right answer! But briefly the audio interface that you will need very much depends on what kind of recording situations you would be aiming to use it in.
- A guitar playing, singer/ songwriter may find that a fairly straightforward audio interface with two mic inputs and two outputs (i.e. one stereo output) will be just fine, and enable recording on vocals and guitar on two separate tracks. A podcaster would look for one mic input – but if you ever plan to do interviews you might consider two so that you can each have your own mic.
- A band would, most likely, require something with more inputs, however, especially if they want to record all the instruments on separate tracks. The other option is just to record the main outs of a mixer, but this will not allow for individual editing of each player and singer.
- A Laptop/ Computer DJ will need an audio interface with at least two stereo (or four mono) outputs. This allows the chosen DJ software to be configured with, for example, a separate cue mix via headphones and a main mix, which is sent out to the main speakers or PA. Alternatively, each ‘virtual turntable’ could be assigned its own output, and connected to a hardware DJ mixer, for more conventional mixing.
Finally when you know how many inputs and outputs you think you will need, it is a case of choosing how you want to connect – USB, Firewire or Thunderbolt.
Technical terms that you may see when looking for an audio interface
Latency: this is where there is a noticeable delay between the actual sound, and its playback in your headphones or speakers which can be very distracting. On modern computers, latency is not a bad as it used to be, but the standard sound cards built into computers are not great, and a dedicated interface will improve this to the point that you shouldn’t even notice any latency. So, if you’ve ever recorded a vocal part, and heard your performance delayed by fractions of a second in your headphones, or used a MIDI keyboard to play a software synthesiser, but encountered a delay between pressing a key and hearing the sound, then an audio interface will fix this problem.
Zero Latency Monitoring (or Direct Monitoring): many audio interfaces have a switch to enable you to hear your sound source directly. So if you are recording your voice, you instantly hear your voice directly in the headphones, there is no annoying delay, and this is certainly a feature to look out for.
Drivers: are pieces of software that enable an audio interface to communicate with the computer. Again, they will help to reduce latency to the point where you won’t notice it.
Pre-Amps: Also known as the “mic pre”, this is the microphone preamplifier, which amplifies the generally very small signal from a microphone up to a suitable level for recording. If you want to make a good recording from a microphone you will need an interface with a suitable input and good pre-amp.
48V phantom power: Some microphones need power, either to drive active circuitry, or, more usually, to polarise the plates of a condenser microphone. If you want to connect up a microphone that requires phantom power then you will need to purchase an interface with a phantom power switch. If you just have a dynamic microphone then this will not be an issue.
MIDI: some audio interfaces also have MIDI in and out. Read our article all about MIDI to find out a bit more and decide if you need to look for an audio interface with MIDI. Most modern MIDI controllers work with USB so this is not as essential to have on an audio interface as it once was.
Sample Rate: This is how many times per second that a sound is ‘sampled’ to create the digital signal. The higher the sample rate the higher the frequency range of sounds that can be recorded and processed. The standard sample rate is 44.1 kHz, which can record sounds up to about 22 kHz. We can’t hear above about 20kHz so you’d think 44.1kHz sampling was sufficient, and often it is. However sampling at higher rates (typically 88.2/96) allows the filters required in digital audio to be well outside the human hearing range, which will improve the quality. So when you are choosing an audio interface this is one of the ways of comparing them. For more information on this rather technical subject there’s a nice article here on sample rate and bit depth.
Balanced/Unbalanced: Unbalanced outputs and inputs are made with ‘single-core plus screen’ cables whereas balanced outputs are ‘two-core plus screen’. (XLR and TRS inputs and outputs are balanced, whereas TS are unbalanced). Many budget interfaces are made to a price and have unbalanced inputs and outputs, which can lead to interference and what is called ‘ground loop’. If you choose balanced outputs and use balanced cables then any interference picked up by the cable is picked up equally by both cores and is cancelled out at the far end, and possible ground-loop problems also disappear because the screen connection is this time not part of the signal path. For simple one or two track recording you should be aware of these differences, but you should be able to make a good quality recording on a budget interface if connected up correctly. If you want to know a bit more about this, Sound On Sound published a fantastic article on audio cables and wiring that attempts to demystify this topic.
Still confused? Please do post your questions in the comments box below and we will try and answer them for you. We want this page to be the ultimate resource for anyone trying to understand, in plain English, exactly what is an audio interface and what does it do. If you still don’t know, we haven’t done our job!