Truthfully, with all the available options and specific situations, I don't really think that there is one "holy grail" when it comes to selecting much of your recording gear. The audio interface is no exception to this rule. Still, a choice has to be made and none of us wants to waste money on gear that doesn't meet our needs.
When I personally look for a new audio interface (or help someone else do the same), I always measure its value by the same set of criteria. I've listed this criteria below and given some explanation as to my thought process.
Lastly, I'll share with you an amazingly affordable option (less than $100) that just might be exactly what you're looking for. Believe it or not, it has every feature I've listed below. I'll include an affiliate link as well (why not? it's almost Christmas). ;)
What features do I really need to consider when purchasing an audio interface?
- Price: This is always my first consideration in the matter. I'm always looking for the best value verses cost option I can find. Cheap isn't always better here but neither is spending more for something I really don't need. Determine your budget first and then see if you can achieve the following features set within your price range.
- USB or Firewire? The 2 most common ways to connect an audio interface to your computer is via a USB or Firewire cable. Interfaces are more often than not, designed to work with one connection type or the other. In this case you need to know which one is best for you. Nowadays this decision has little to do with actual performance as both styles will work well. Also, make sure you have a free port (USB or Firewire) on the computer you intend to record with. Nothing worse than buying a new interface and realizing you'd have to disconnect your mouse to actually use it.
- What recording software or DAW will you be using? This can often be a "kill two birds with one stone" situation. Many audio interfaces come with recording software. If you're new to recording, you may want to start by using the software that comes with your audio interface. If not, then it's important to make sure your new gear will work with your DAW. A little research can answer this question most of the time.
- Will it work with my computers OS? Unless you love frustration, finding out this information can save you a huge headache. The real catch here is whether there are software drivers to run your new interface, that work with your OS. Things to highly consider here and PC vs Mac and 32bit OS vs 64 bit. Also the age and version of your OS can mean the difference between your new gear working out of the box, or not at all. For PC users find out if there is an ASIO driver available for your audio interface (I'm told CoreAudio is often best for Mac). These drivers will give you the best latency and most reliable performance.
- Online Reviews: I've always taken the time to research the reviews of other people who have used the audio interface I'm considering purchasing. It's important to actually read both the positive and negative opinions. There have been times where the negative view was specific to a situation that would not be an issue for me personally.
- Quality Preamps: Again, reviews help get a good understanding here. The same holds true with companies who have been in the industry for years. Focusrite, M-Audio, PreSonus are a few manufacturers that typically create interfaces with excellent preamps (not an all-inclusive list btw).
- Recording Quality: Nowadays I'm not interested in an audio interface that can't record at 24bit and 48kHz. I've also not found a need for higher quality in my home studio either. I've found 96kHz file to be far to0 large for the real gain in audio quality.
- Phantom Power: If you intend to use a studio condenser you're going to need phantom power at some point. It's much easier, in my opinion, to have this built into the interface itself.
- Direct Monitoring or Zero Latency Monitoring: This is simply the ability to hear what you're recording before it gets processed by your DAW (or with zero delay from certain DSP processors). This is a must for me as well.
- Stereo/Mono Record Monitoring: This options makes it much nicer to record your vocal and listen to it in mono while you're tracking. This way it's in both ears and not just one channel or your interface.
- Balanced Outputs: If you're going to use a pair of studio monitors, it's best to have a balanced output to feed to these speakers.
- Input/Playback mixing: This isn't a necessity but sure makes life easier when you're trying to record. It's best to hear your input louder than the playback and this provides that option.
- MIDI: Yes, I still use MIDI and I would always recommend getting this option, even if you don't think you need it initially.
- Headphone output with separate volume control: If you're tracking it's best to use headphones and not live monitor speakers. With a headphone that has a separate volume control you can turn off your studio monitors and track with just headphones.
- Enough inputs for your needs: I don't typically need more than two channels at any given time so that works for me. You may need more, consider how many tracks you need to record simultaneously before making your purchase.
- TRS Insert options per channel: This is also not a complete "have to" but can come in very handy. If you ever want to compress or add a noise gate while you're tracking a vocal. This is the best option.
- On-bard Meters: This is also more of a perk than you need. Most of the time I use the meters in my DAW to set my levels. Having an on-board option could be simpler when you're wanting to get started tracking quickly.
- On-board Power Via USB/Firewire: If your setup is portable like mine, then having an additional power cable to plug-in can be a pain.
I'll be the first to confess that this may be a hefty list for some. I've also had audio interfaces that did not have every feature I've listed here. That said, I've recently been testing an option that is quickly become an amazingly affordable favorite of mine.
If you're looking for something that is less than $100 and has every feature I've listed above, then check out the M-Audio M-Track.
If you have just a bit more money to work worth but still under the $200 mark, my first choice is the Focusrite Scarlett 2i4.
Also, if you know someone else who could really use this list, please take a moment to share it with them.