Part 1: You And Your Audio Interface

As nice as your Mac's sound card is, it's not really designed for recording music. You'll need to pick up an audio interface, which is sort of like an industrial-strength sound card made specifically for converting analog audio (coming out of a microphone, instrument or sampler) into digital audio (the kind that lives in your computer). It's a sound card on steroids, in other words.

Most prosumer audio interfaces are external, connecting to your Mac via FireWire or USB, and most feature microphone pre-amps and tools for routing audio in and out. They also feature 1/4" and XLR (or "Neutrik" combo plugs that combine the two; see the image of the M-Audio FireWire 410 below), which are standard in audio production. Finally, many audio interfaces also feature MIDI inputs and outputs (for controlling external synths and other devices) and digital inputs / outputs for connecting the sound card directly to digital audio sources like high-end mixing boards. Many companies are incorporating audio interfaces directly into their mixers and even their synthesizers now as well, which can make life easier.

The 800-pound gorilla in the audio interface world -- indeed, in digital audio production in general -- is Digidesign, makers of Pro Tools, which is widely considered to be the industry standard hardware / software recording solution. Digidesign's audio interfaces start with the entry level MBox 2 ($495 list price) and work their way up to professional grade systems like the HD 3, which lists at $13,995 (if you have the means and the wherewithal for that, you probably don't need my advice, though).

Another popular manufacturer is M-Audio. (Both M-Audio and Digidesign are actually owned by Avid; there are versions of Pro Tools for both companies' hardware, though that hardware can also run any other DAW like Logic or GarageBand.) M-Audio is primarily known for their consumer / prosumer products, and their gear is generally well-considered by their target audience of bedroom producers, DJs and musicians who want a simple workflow to record their own work without relying on studios or engineers.

I personally use an M-Audio FireWire 410 (list $399, though you can find it easily for $250 or less), and haven't had any real problems with it since I bought it in 2004, even though I toss it in a bag regularly for DJ gigs and field recordings.


Of course, there are dozens or more manufacturers making audio interfaces (including Mackie, Allen & Heath, Novation, Mark Of The Unicorn and many others), and your choice is really only limited by your wallet and your needs. Different interfaces are geared for different uses, so make sure to check out a lot of them before buying.

Here's seven things to look for when purchasing an audio interface for your home studio:


1) Number of inputs and outputs. How many do you need? If you're a singer/songwriter recording vocals and solo instruments, you may only need a box with two mono inputs and two mono outputs. (Two mono = one stereo.)

If you've got a band and you want to record multiple instruments simultaneously, you may need sixteen or more inputs, to record each instrument in stereo. If you're a DJ or live electronic artist, you'll want at least four mono / two stereo outputs -- one pair for cueing and one pair for the sound system.

Digital inputs and outputs are important if you're pulling or pushing audio off of DATs or other digital sources...but most home studio users aren't, so unless you specifically need them, they're not a key feature. I've never used mine, for example. Many manufacturers will include them when listing the number of inputs/outputs, though, so pay close attention to how many analog inputs/outputs your prospective interface has. The FireWire 410, for example, has four inputs and ten outputs, hence the name -- but two of the inputs and two of the outputs are digital, so it only has two analog inputs and eight analog outputs, as you can see in the picture above. (The front inputs are just clones of the back inputs.)

2) Preamp quality. The microphone preamplifier in your interface provides the necessary amplification for your microphones required for recording. Unless you've got or want to buy expensive outboard gear, you shouldn't skimp here. Many producers and technicians believe that a great preamp is more important than a great microphone for recording vocals.

Most mid-range interfaces between $300 - $1000 will have pretty good preamps that will probably do the trick for most pop music vocals / instruments. You still might want to invest in a dedicated preamp, though; there's a great (if grammatically challenged) guide at Tweakheadz on choosing and purchasing one.

3) Bitrate. The quality of a digital recording -- aside from the quality of the audio going into it -- basically has to do with sample depth and sample rate (let the comment flaming begin). The higher the better, in this case, and you're not going to want an interface that won't let you record at a minimum of 24 bit, 48KHz audio, which is slightly higher than CD quality. Luckily, all but the cheapest interfaces meet this criteria, but you should check anyway.

4) Build quality. While your audio interface may never leave your desk, you're probably going to be plugging and unplugging cables from it a lot as you record. You want to make sure it's not going to fizzle out on you thanks to cheap construction.

If you buy yours at a brick and mortar music store like Guitar Center or Sam Ash, try to get the sales clerk to let you inspect the interface before you buy it. Ask him or her if you can test the jacks out. What you want is something that feels sturdy; the sockets shouldn't wiggle, or they will eventually come loose inside and stop working. Stick a guitar plug in and out of each socket. There's no special musician's secret here: if it feels cheap to you, then it's cheap, and you shouldn't buy it.

5) Interface type. Most modern audio interfaces are either PCI / PCI Express for internals or FireWire / USB 2.0 for external. One is not necessarily better than the others, although I would hesitate at a USB 1.0 interface.

For Macs, FireWire is a pretty solid bet, but if you plan to use your interface with multiple computers or take it outside of your home studio, USB is more common on PCs. Again, it depends on your needs.

6) MIDI capability. MIDI is Musical Instrument Digital Interface, a protocol for controlling and receiving data from external device like synthesizers or keyboard controllers. If you're planning on using anything like an external mixing device or a keyboard to control software synthesizers, you probably need this. You can buy external MIDI interfaces ... but why bother, when most quality audio interfaces already come with MIDI built in?

7) Driver compatibility. Because Macs are so prevalent with musicians, no respectable audio hardware company would make a bit of kit without Mac drivers. But as we've discovered recently, some drivers don't play well with some OS updates, and so it's vital to make sure the box you want to buy works with your current hardware / OS setup. And again, if you're planning on using the device with multiple computers with different operating systems, make sure there are Windows Vista / Linux drivers available as well.

That's the basics on picking a hardware interface. If any of our more experienced readers would like to pop in to the comments of this post and recommend particular makes and models of audio interfaces for people just starting out, I'm sure it would be roundly appreciated.

Next time: digital audio workstation software!