Any professional musician or studio engineer that uses a computer as part of their creative process will eventually find use for an audio interface. In terms of computer audio products, an audio interface is the hub that connects all of your external devices to your computer and your computer to them. Almost all stock computers and laptops won’t have the ports necessary for connecting musical equipment, thus an audio interface becomes incredibly vital.
An audio interface typically attaches to your computer via USB or FireWire, and acts as a translator. They will take binary information from a computer and translate it to audible information, as well as turning audible information and translating it to binary. Using an audio interface is essential to anyone using computers for reference and for recording because most stock sound cards will not give you professional sound and leave very little room to expand the possibilities of your recording setup. All of the newer audio interfaces are incredibly versatile and allow you to connect midi devices, monitors, headphones, other digital recording components, and actual instruments.
After understanding what audio interfaces do and why they’re so important, the next step is to understand the essential parameters that differ between products, and which is the best to get for your own studio. After all, it’s easy to be confounded by the different price points; understanding what you are (or aren’t) getting between a very cheap audio interface ($50 or less) and an expensive one ($1000 and up) is not an easy task for the home studio shopper. The key price differentiators are:
Firstly, audio interfaces mostly vary in the amount of connection ports they have, and it stands to reason that the more inputs and outputs an interface has, the more expensive it will generally be. Therefore, if you don’t intend to plug in too many external devices beyond a few essential pieces of equipment, it’s probably best to find either a cheaper option, or a smaller but higher quality product in the same price range. On the other hand, if you want to connect several instruments and other equipment (e.g. guitars, hardware synths, multiple microphones, etc.) to your computer, you’ll generally need a larger audio interface with more connections, which will likely be on the more expensive end.
The other deciding factor is the overall sound quality of the audio interface determined by bit depth and sampling rate. Generally speaking, most interfaces nowadays will have the required quality for sound recording purposes. However if you’re in need of something more, it would be wise to get an interface that can handle a higher sampling rate or bit depth of 24 or 32 bits.
And finally, company reputation can account for audio interfaces at different price points. Manufacturers such as Behringer, Focusrite, PreSonus, Apogee, RME, and M-Audio (just to name a few) make interfaces in a variety of configurations and budget ranges. While the cheapest audio interfaces can certainly suffice for tight budgets, be aware of the sacrifices you might be making in build quality, the manufacturer standing behind their product, and how diligent the manufacturer is in releasing software and driver updates.
Overall, most audio interface manufacturers do a great job of providing information for their products and a little research will definitely help you find the right one for you. Have a question about what audio interface you should buy? You can ask the Equipboard community in the forum.