Microphones 101:
A Beginner’s Guide to Macs and Mics
If you want to make recordings on your Mac, you need a microphone. But microphone choices can be bewildering. Options range from the tiny mic already inside your Mac to high-end models costing thousands of dollars.
This article surveys the various types of mics and audio interfaces to give you a sense of what to expect in terms of price/performance.
The $0.00 option. All Macs have a built-in microphone — it may be all you need if sound quality isn’t a big issue. For basic tasks like talking on iChat or capturing quick voice memos, the built-in mic works just fine. If your sole concern is basic intelligibility, you’re good to go. This is also a good first choice for the beginning podcaster. GarageBand’s Podcast studio feature includes speech enhancing technology, which will actually improve the sound quality of your speaking voice no matter what microphone you use.
The external mic upgrade. A decent external mic makes recordings sound fuller, clearer, and more detailed, with greater warmth and intelligibility. In other words, they’re nicer to listen to. The bare-bones tone of the built-in mic suffices for a brief memo, but it will fatigue the listener’s ear over the course of a 45-minute podcast. And if you plan to record anything musical, you’ll definitely want to go the external mic route.
But using an external mic adds another concern: how to get the sound from the mic to the computer.
Your Mac has a built-in input/converter: the 1/8-inch line-input mini-jack situated next to your headphone output jack. But it’s not the ultimate solution for great-sounding recordings. Like the built-in mic, it offers no-frills sound quality. And you can’t plug high-quality mics into this sort of jack. (There are plenty of budget mics that fit this jack, but their sound quality probably won’t be much better than that of the Mac’s built-in mic.)
Most microphones and mic cables use a three-pin XLR connector. Photo by Joe Gore and Elise Malmberg.
Almost all professional mics employ a large three-pin XLR connector rather than a small phono plug. And it’s not just a matter of fitting the big plug into the small jack — you need a preamp to boost the low levels of microphone signals, and an analog-to-digital converter to translate the mic’s analog signal into digital data. Many mics also require an electrical power source to operate.
But don’t panic! Most audio interfaces do all those tasks — and more.
Audio interfaces — a PreSonus FireBox is pictured here — convert your mic’s analog signal into digital info your computer can understand. They can also improve the sound quality of your recordings and make the process faster and easier.
The audio interface advantage. Audio interfaces have XLR jacks for connecting mics, and USB or FireWire jacks for communicating with your computer. Even the simplest interface (like the no-frills models that sell for under $200) provide major upgrades in audio quality. They let you record at 24 bits, which sounds better than the 16-bit audio supported by Macs alone. They also minimize latency — the amount of time your computer needs to makes sense of sounds. With high latency, there’s a noticeable delay between what you hear in the room and what you hear back through your headphones. Latency isn’t much of an issue if you’re recording, say, a podcast voiceover — you’d just turn off your headphones while you speak. But if you plan to overdub multiple parts — for example, listening to a guitar part you just recorded while adding a second one — latency can be a serious problem.
What do you get when you spring for a higher-priced audio interface? Probably even better sound, thanks to superior preamplifiers. You might be able to record simultaneously via two, four, or more microphones, which is great if you’re trying to capture multiple musicians playing live, or several people speaking in an interview. Some interfaces include built-in effects, such as vocal reverb or simulations of electric guitar amplifiers. (So does recording software such as GarageBand and Logic Pro. The interface may offer specific sounds your software lacks, or free up CPU resources so you can run larger sessions.)
