I've spent years talking about this with musicians and sound engineers from all over India, so I thought I'd write a small article about this, sharing my thoughts. Lets start by understanding what an audio interface does!
The audio interface is the heart of any home studio and performs the following functions:
- Preamplifies (gives a clean boost) your input signal to line level (-10db) suitable for recording.
- Converts your analog input audio signal into a digital wave audio file. This is called Analog to Digital Conversion (ADC).
- Provides processing power to provide latency-free playback while recording and mixing.
- Converts your mixdown to an analog audio signal. This is called Digital to Analog conversion. The DAC convertor ensures that what you hear is high-quality reproduction of your mixes. This helps you create better mixes!
Why can't you use your computer's internal sound card to record songs?
Your computer's internal sound card is optimized for one thing only - playing back sound. The only thing they've spent money on is the DAC (Digital to Analog convertor) so that you can listen to music/movies/games. It has a low quality preamp that will dramatically downgrade your input signal, it has virtually no processing power, and your mix-downs will sound like shit. Add to that a one-two second latency, making it impossible to track or mix your songs comfortably. (In real life, you need a sub 10millisecond latency to lay down tracks).
What recording software will you use?
If you answered Pro Tools, you should immediately consider sound cards made by Avid-owned companies, which are M-Audio (entry-level) and MBox (pro-level). Even though Pro Tools 9 and 10 are compatible with all audio-interfaces, Avid cleverly bundles Pro Tools 9 with almost all their M-Audio and MBox cards at a ridiculously low price, giving you instant value for money.
If you're going to use Cubase/Nuendo/Ableton Live, your best choices are Focusrite/M-Audio/Presonus/Cakewalk. These interfaces usually come bundled with 'lite' versions of one of these softwares which support upto 16 tracks.
How many (simultaneous) inputs do you need?
The truth is, most songs are recorded track-by-track, and 2 microphone preamps usually suffice because you can record each input signal in true stereo. The only reason to consider audio interfaces with 4 or 8 preamps is when you're going to record several instruments or voices simultaneously, which is very unlikely in a home studio environment, because the room simply won't sound good enough without expensive acoustic treatment! So I'm going to recommend you choose an interface with one or two high-quality preamps and one high-impedence (Hi Z) instrument input.
Are you using a Mac?
If you're using a Mac, just pick up an Apogee One or an Apogee Duet, and you can start making world-class recordings right away. Theres also a lot of interfaces available for the IPad and Iphones!
Who makes the best preamps in the home studio segment?
This is a tough question, but I've rated them in the order I feel is right. I may be biased :)
RME/Apogee/MOTU - 9/10
Focusrite / Mbox - 8/10
Presonus - 7/10
M-Audio/Cakewalk/Tascam/Mackie/Line 6 - 6/10
Firewire or USB or PCI?
Firewire is about to be replaced with USB2.0 and perhaps USB 3.0 as the universal standard for audio. If you're recording only two simultaneous tracks at a time, even USB 1.1 is good enough, but with USB 2.0, you'll get super low latency and its now an industry standard, so you cannot go wrong.
Most people don't know that USB 2.0 is faster and has twice the bandwidth of Firewire 400, which has been an industry standard for pro studios worldwide.
Firewire interfaces may require you to buy an additional firewire card for your computer. For a home studio, its simply not worth paying the extra cost. Go in for USB 2.0 if you can, and if you can't, settle for USB 1.1. If you're using a computer and not a laptop, seriously consider buying an internal PCI Audio interface like the M-Audio Delta 1010LT. in practice you will find that PCI audio interfaces are more stable and have far better processing power than USB interfaces.
Best interface for recording demos at home?
You need to think about picking up a Line 6 GX, UX1, or UX2. While Line 6 is not considered a serious player in the pro audio market, they actually make some impressive stuff! The Pod Studio GX, UX1 and UX2 may be average interfaces, but they come bundled with POD Farm software which has over 80 adjustable guitar amps, bass amps, preamps and more, letting you plug in your instruments (and microphones) directly into the interface and creating a wide range of tones. Excellent for song-writing and quickly tracking your ideas into your DAW. I wouldn't recommend POD Farm for professional recordings, but for tracking demos, it rocks.
One really unique interface from Line 6 is the KB37, which includes high-quality preamps (better than UX1/UX2) as well as a built-in 37 key MIDI keyboard! I'm mentioning it seperately because I've never seen anything like it from any other manufacturer. It's underrated and not seen often in Indian home studios, possibly because of lack of availability in the market.
What else will I need?
When you buy an interface, always budget for picking up a high quality microphone, some studio-grade XLR, TRS, and RCA cables, a mic stand, a powerful computer, software (don't pirate), and a pair of good headphones or studio monitors. I'll write articles about choosing these very soon :)