Once you have something creating sound and a way to capture it (like a microphone), you have to get that sound into your computer for editing. I will refer to these kinds of devices as “interfaces”. In a nutshell, they capture your source (either analog or digital), convert analog sources to digital, and then feed those sources to your computer. Some interfaces are all-in-one setups and don’t require a computer.
Basic components of interfaces
- A/D Conversion (analog to digital conversion). Almost all interfaces will have some kind of A/D conversion. This takes a signal from a microphone and converts it into nice little ones and zeros so your computer will understand your audio.
- Microphone Pre-amps. Many (certainly not all) interfaces will have a mic preamp or two (or eight) built in. If you are recording with microphones, you need a preamp, and having a decent preamp built into your interface is nice. Many of these preamps will also have some kind of instrument DI capability built in as well.
- Basic computer connectivity. Most interfaces hook up to your computer with either USB or firewire.
What to look for
Number of inputs
The first thing you’ll need to consider is how many inputs you need. Do you need to record 6 to 8 inputs at one time (like mic up a drum kit)? Then you’ll need an interface with more than just 2 inputs. If you’re a singer-songwriter guitar player, you can probably get by just fine with a 2 or 4 input interface, allowing you to record guitar and vocals at the same time.
USB or firewire? Here’s my take: Firewire is more stable (and is consistently faster), but USB works just fine, especially for a smaller interface with just 2 or 4 inputs. Not all computers have firewire ports, so make sure your computer is compatible with the device you’re looking at.
Lots of factors will hike up the price of an interface in a hurry. Number of inputs, quality of A/D conversion, quality of mic preamps, build quality, etc. My advice is to get the biggest bang for your buck in 2 main areas: Mic preamps and A/D converters. Those two components have by far the largest impact on the sound quality.
Bit depth and rates
16 bit, 44.1K. 24/96. 24/192. What do all these numbers mean? These numbers describe the resolution of the audio files your interface gives you. Higher numbers mean more resolution (but not necessarily higher quality audio). Compact discs are written at 16 bit, 44.1 K, so ultimately, you’ll probably bounce down your songs to this rate, but recording at a higher rate can give you a better sounding product. Almost all interfaces out there will support 24/96. Personally, I use 24 bit recording and 44.1 Kz. I’ve tried 24/96, and honestly, I can’t tell the difference. I wouldn’t pay a lot more to get 24/196, unless you’ve got money to burn. You might disagree with me, and if so, your ears are probably better at hearing the difference than mine.
Ultimately, nearly ALL your listeners will be listening to MP3s, and there is no way they’ll be able to tell a difference between 16/44.1 and 24/192.
What do I use and recommend?
My main recording interface is a PreSonus FirePod (now the PreSonus FP10). The photo up above is my actual FirePod. I’ve used it for years, and it’s never let me down. It sounds great and is easy to use, especially for those on a Mac (though I’ve used it in a Windows environment with no problems). It has 8 inputs, which might be overkill for you if you’re on a budget. In that case, look for a PreSonus FireBox. PreSonus has a “FireStudio” line out now. I haven’t used any, but I would imagine they’re just as good or better than the stuff they replaced.
I’ve also used M-Audio gear, and it worked great as well. Apogee, Mackie and MOTU (among others) have good reputations, but tend to be a bit more expensive. If you have a lot of room in the budget, check out Avid (previously Digidesign).
Before buying anything, search out user reviews and see if there are known issued with the software and operating system you’re planning to use.