What is an Audio Interface?
Our Guide to common music related terminology continues with an answer to the question, ‘What is an Audio Interface?’
An Audio Interface is a device that connects musical instruments and recording equipment, such as microphones, with a computer to allow musicians to record their source sound.
In this addition to the ‘buyers guides’ section of our website, we will shed light on what an audio interface is, what it does, why you would want one, and which one you’re going to need.
What is an Audio Interface? A little bit of history
The PC was initially developed as a business machine, and so, in its earliest incarnations, its display capabilities were limited to monochrome, and it had no sound at all other than a warning ‘beeper’. As technology advanced, computers such as the Commodore Amiga, and the Apple Macintosh, began to feature more sophisticated digital audio playback. Still, the PC was silent. To rectify this, however, companies began to develop additional, internally fitted expansion cards (in essence, plug-in circuit boards known as sound cards) to add higher quality sound reproduction to a standard PC.
As computers became more powerful still, software was developed that allowed them to be used as a multi-track recording studio (meaning individual musical parts could be recorded separately, but ‘over the top’ of each other, and each track could be adjusted in level, pan position and more, after recording).
At this point, on-board sound cards generally featured an output to connect speakers and headphones, and usually an input for a microphone. This was inadequate for recording audio in a more serious or professional situation. In addition, most soundcards suffered from a problem known as latency, whereby, if you were recording something, there was a noticeable delay between the actual sound, and its playback in your headphones, for example, which could be very distracting. To rectify this, soundcards were developed specifically for recording audio.
These featured higher quality audio reproduction than the ‘multimedia’ type sound cards that were generally featured in PCs (and Macs), had high quality, dedicated audio inputs and outputs, and could run with incredibly low latency (so low that the user wouldn’t even notice it was there). In addition, some had increased numbers of inputs and outputs, allowing for multiple tracks (i.e. individual microphones, instruments etc.) to be recorded at the same time, or recorded tracks to be sent to individual channels of a mixing desk, for example. So where does the audio interface fit into all this?
In essence, a sound card is an audio interface, as it is an interface designed to allow audio to be recorded or played back in various ways from a computer. However, the term ‘audio interface’ did not arise until a little later…
As laptops became more powerful, the dream of a truly portable recording studio became a possibility. The major obstacle was that conventional soundcards connected internally (via ISA or PCI connections), which was impossible with a laptop.
This problem was solved when manufacturers began to make sound cards in external boxes, which connected to the computer via a USB or Firewire connection (the kind you might use to connect a printer or camera to your computer). Thus, what is conventionally termed the audio interface was born. It is, in a nutshell, an external soundcard.
Why would I need an Audio Interface?
Anyone who is remotely serious about recording on a computer will need an audio interface at some point. Whilst, on modern computers, latency is not the issue it once was, 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.
The other main advantage of an audio interface over on-board sound cards is that, because of the greater physical size, 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.
Which Audio Interface do I need?
The audio interface that you will need very much depends on what kind of recording situations you would be aiming to use it in, as this will dictate how many inputs or outputs you may need. 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) may suffice, allowing the guitar and vocal to be recorded to separate tracks at the same time. A band would, most likely, require something with more inputs, however. Once you know how many inputs you need, check whether your computer has a free USB or Firewire connection (not all PCs have Firewire connections, so always check before buying anything).
Here’s a little summary of an audio interfaces most common uses, with some current recommendations:
- Singer/ Songwriter – Would only require an audio interface minimal inputs and a stereo output. We recommend the Focusrite Scarlett Solo Studio Second Generation (2nd Gen) Recording Package, Focusrite Scarlett 2i2 Second Generation (2nd Gen) USB Audio Interface or the Presonus Audiobox iTwo.
- A Band, looking to record their songs more professionally – Would probably need an audio interface with a minimum of eight inputs (ideally microphone inputs), so that a drum kit can be recorded with multiple microphones to separate tracks, or several players can perform together, whilst keeping each instrument separated within the recording, for adjustment later.
We recommend the Focusrite Saffire Pro 40, Zoom R16 or Focusrite Scarlett 18i20 second generation (2nd Gen).
- 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.
We recommend the Native Instruments Traktor Audio 2 Mk2, Native Instruments Traktor Scratch Audio 6 or the Novation AudioHub.
View a complete range of audio interfaces on the Dawsons website.