What is it?
Recording interfaces are essentially soundcards that allow you to input audio into your computer and output audio from it.
Many recording interfaces have preamps built into them, which power microphones.
The price of recording interfaces is often broken down into cost per preamp. For instance, a $1,000 recording interface with 2 preamps built in has a cost of $500 per preamp.
Why Do I Need An Audio Interface Designed For Home Recording?
I’m often asked why it is necessary to purchase a real deal audio interface/sound card designed specifically for home recording. In fact, there is nothing wrong with your computer’s soundcard for playing back mp3s and other “consumer grade” activities.
However, when you begin to record music on your computer, you have left the “consumer grade” world far behind.
Your stock soundcard will limit your ability to work. That Soundblaster soundcard (which I’m sure came with an amazing graphic on the box) won’t cut it for home recording either.
Latency is the time it takes for your computer to process stuff. In our case, this is usually associated with the amount of delay it takes for sound to go in and out of your computer’s soundcard.
Let’s assume we are going to play a MIDI Controller / MIDI keyboard by running MIDI into the computer. This MIDI will trigger a synth or sample. In this example, let’s say we fire up some piano samples.
When we strike a key, there should be no noticeable lag in time. In other words, we should hear the note immediately just like we are playing it through a standard keyboard.
Your stock soundcard is probably going to take a while to process this note. It is slow and cheap by design and will have to sit around and think about the note that needs to be played.
I’ve seen stock soundcards take as long as 250ms to play a note. This means every note you strike will be behind 250ms. At 60 beats per minute, this is a full quarter note! The solution is to use a low latency audio interface that can process this piano note in just a few milliseconds where the delay is not even audible by the person playing.
The issue of low latency isn’t limited to the playback of virtual instruments (synths and samples) on your computer. It becomes an issue anytime you want to monitor from within your recording software.
I monitor through my recording software every step of the way from the drummer to the vocalist, all headphone or studio monitor mixes are done through the recording software (The exception to this is when I need more than one mix for individual players. In that case my audio interface uses a DSP mixer to give individual mixes to each player.)
I prefer to use the recording software for monitoring because it gives me ready access to compression and reverb. I couldn’t imagine going back to the days when my vocal headphone mixes did not have compression. This would be impossible without a low latency audio interface.
When I fire up an electric guitar, the first thing I do is move the amp to an isolated area so I don’t have to listen to it. Then I slap up a mic and start listening to the guitar through the studio monitors. This allows me to hear exactly what the mic is picking up and make adjustments as necessary. This would not be possible without a low latency audio interface.
From what I hear, stock Mac soundcards tend to be a little better in terms of latency, but I do not know this from my own personal experience. I know of very few Mac users who are using the stock soundcard as their recording audio interface simple because there are other desirable features that the stock soundcard simply won’t have.
You may get lucky and find that your current soundcard is adequate for low latency recording. Go ahead and try cranking the latency down to the point that latency is acceptable for monitoring.
If you can reduce the latency low enough without static, clicks, pops, and the infamous “blue screen of death” you may actually be able to get away with using your computer’s stock soundcard.
Analog To Digital (A/D) Conversion
The device that converts an analog wave to a bunch of numbers is known as an AD converter. We have to convert signal from analog to digital so that computers and other digital devices can store and manipulate the “data”.
AD converters are not created equal. The higher the quality of conversion, the more accurate the sound. Generally speaking, A/D converters are usually not as prone to subjectivity as other links in the recording chain.
In other words, there really isn’t a case I know of where a person wanted poor A/D conversion as a cool “effect”. I’m guessing that the guy singing through guitar pickups on a major label recording is still being routed through high-end AD converters.
Poor A/D converters tend to sound harsh and not as smooth as a high-end analog to digital converters.
If you are using an audio interface specifically designed for music recording, you probably won’t notice much of a difference between the converters in your audio interface and the ultra high-end converters made by Mytek, Lavry, Lucid, or Apogee. (I’ve never had a client notice when I switched from my Myteks to my stock Delta 1010 converters).
However, it’s possible that the converters in your stock soundcard are so bad that the difference should be quite noticeable between your stock soundcard and a real audio interface.
The converters in the stock soundcard that came with your computer were simply not designed for audio recording. They may sound okay at first, but I’m confident that you will notice a difference when you switch to a real audio interface.
The interface above has no inputs in the front. It has two inputs in the back. One is an XLR input, on the right side. To the left of it, is a 1/4″ input. Microphones usually use XLR connections and instruments such as guitars usually have 1/4″ connections. Some interfaces may also have a midi input.
The interface pictured above has a 1/4″ headphone out in the front. It also has 1/4″ line outputs in the back, which are standard on most studio reference monitors. Some studio monitors may have an XLR port for audio in, but XLR to 1/4″ cables are easy to find and do not result in loss of quality.
Sample Rate and Bit Rate
Samples rates and bit rates are a very technical matter and all you really need to understand is that higher sample rates and bit rates result in marginally higher quality recordings.
CDs are 16bit/44.1KHz and most recording engineers prefer to record at a slightly higher bit rate and sample rate just because it makes them feel better. In the end, you have to down-convert everything down to the CD compatible bit rate and sample rate.
I personally recommend 24bit/96KHz as that is probably the most common combination. The difference in quality is practically unnoticeable to the untrained ear.
If a recording interface has a preamp built-in, it may or may not have phantom power on that preamp. Phantom power is required to power all condenser microphones, which are widely used in studio recordings.
It is almost an essential feature on your preamp. However, if you’re not planning on using your interface’s built-in preamp, you don’t need to worry about it having phantom power. The phantom power on and off switch is usually denoted by a ” 48v” on most music equipment.
USB vs Firewire
If you plan on using live effects, where the sound goes in from your microphone, gets effects applied live inside your computer, and comes back out of the speakers in its modified form, you may want to consider the latency of the process.
Latency is how long it takes for sound to come back out of your speakers after being picked up by your microphone. In live settings, it is crucial to keep latency at a minimal. Anything more than 30 milliseconds can easily be noticed.
Firewire is almost always a better choice than USB in terms of latency. However, Firewire devices are getting less popular and USB recording interfaces dominate the market. Firewire ports are also hard to find on computers.
If you absolutely need to monitor your processed audio live, Firewire is the way to go. Otherwise, USB works great.
Some interfaces have built-in DSP effects. This simply means that the recording interface has built-in effects inside it that take no toll on your computer’s resources.
This can be very beneficial if you have a slower computer. However, I have found these effects to be subpar quality and most interfaces do not offer them.
8 Tips for Buying an Audio Interface For Your Home Studio
#1 – Should I By A Used Audio Interface?
Interfaces generally have major issues right from the beginning or they work and work for a long, long time. Being that most audio interfaces are mass produced, I prefer to look at the first owner as the world’s least expensive quality control feller.
If an interface doesn’t break the first month, it’s probably going to last a decade. Use your gut. I’m sure there are exceptions.
#2 – Require At Least 50 Reviews
I don’t buy anything expensive anymore unless it has 50 OUTSTANDING reviews at Guitar Center, American Music Supply, Zzounds, or Amazon PERIOD!
It’s unfortunate when you have to dig and dig through forum threads and find yourself reading between the lines to see what the author implied. Don’t do it.
Find people like you who have clearly used the thing and are happy. Be careful with people in the honeymoon phase or suffering from the confirmation bias.
Some people will glowingly review an interface BECAUSE they bought it and not because they’ve used it. Way too many people have been burned by an interface that was discontinued in a year. Be careful.
I find myself often rooting for the underdog with a lot of gear. Unfortunately, if the company didn’t market the interface hard enough to get a ton of initial reviews who knows if you’ll be able to sell an otherwise great audio interface for a reasonable price when you are ready to move on.
#3 – Know Exactly What Features You Need In An Audio Interface
Not sure what features are important to you? If you aren’t up all on all the available features, use the Audio Interface Wizard 2.0‘s help section. It covers just about every feature under the sun and will save you a TON of time finding audio interfaces that meet your requirements.
#4 – Is The Company Taking Audio Interfaces Seriously?
Take a look at the Allen and Heath ZED420. Allen and Heath are a fine audio gear company. I’m sure this mixer does the job well. Maybe it’s Allen and Heath. Maybe it’s Sweetwater. Regardless, they don’t even bother telling us if the audio interface is USB 1.1, USB 2.0, or USB 3.0. Does the interface have 2 inputs or 20? We don’t know.
I’d absolutely hate for someone “just looking for a mixer that records” to fire this thing up and realize they can only record 2 tracks at the same time when they really needed more.
Even when cracking the manual open, it’s not abundantly clear what’s going on. They’ve dumbed the info down way too far for my tastes.
I get a similar feeling when they simply slap USB 2.0 or Firewire on a high-end converter. Lynx has been a highly respected audio interface company for a long time. (Some considered Lynx to make the best interfaces, actually.) If a person didn’t know that, it would be easy to think they hadn’t taken the audio interface part of the Lynx Aurora 16 LT-USB seriously simply based on the marketing.
An audio interface is not something you just slap to a set of converters even if the marketers tend to imply that.
Make sure the company you are considering buying from has given you all the information you require. If not, move on to one who seems to be taking the audio interface seriously.
#5 – Read The Manual Before You Buy
I recommend this with all gear. The truth is, most marketing departments are run by former car salesman with chainsaws and chipped shoulders. The marketing for most audio interfaces couldn’t be more hype, more BS, and vaguer. IRS agents can’t even figure it out.
It’s hard to find real info and generally the only place you can expect to hear the truth is in the manual. Take note that companies have figured this out and often include sales pitches rather than actual information in their manuals, too. Great!
#6 – A Picture Is Worth $1,000
Make sure to take a look at the pics. No, I don’t care about color schemes. We need to make sure all the features you think are there are actually there. They can say they have ADAT or AES all day long, but if those features aren’t in the picture someone has some explaining to do. This helps clear up the issue of there being 16 different versions of the same interface model.
Offhand, the MOTU 8Pre has both a Firewire version and a newer USB 2.0 version. If you Google the MOTU 8Pre you’ll see no overt indication of USB 2.0 or Firewire on that Google page. If you click on the the MOTU.com link you’ll go to a page that only discusses the USB 2.0 version and doesn’t make a mention of the MOTU 8pre with Firewire. If you go to Ebay you’ll see the used MOTU 8pre interfaces are almost entirely Firewire.
This isn’t a slam on MOTU although they could have easily avoided the confusion. MOTu is a solid company with a great reputation. It’s a shame that even reputable companies require you to look at the pics before buying, but that’s the nature of the audio interface mess.
#7 – Avoid The Scare Tactics
You’ll be very close to buying an audio interface that’s within your budget and meets your well-researched needs. Then you’ll encounter something that says, “Our interface contains the highest grade plutonium converters and krpytonight preamps that blow away all other preamps.” Suddenly, you are highly concerned the preamps in your audio interface don’t add up and end up other thinking the whole thing.
Don’t. These types of scare tactics have very little basis in reality. Rely on the reviews from your peers and you’ll do fine. It’s the web so you have to take almost EVERYTHING with a grain of salt pork and a shot of bourbon.
#8 – Ask!
Not sure if X interface is right for you? Just ask.
- Find an interface that meets all of your needs with the Audio Interface Wizard 2.0.
- It’s up to you whether a used or new audio interface is the right choice, but I consider used audio interfaces a safe bet most of the time.
- Make sure you find plenty of positive reviews, take a look at the pics to be sure you are getting what you think you are getting, read the manual before pulling out the credit card, and
don’t let anyone scare you out of buying an interface. If a person has a real issue with an interface having many, many great reviews, they can substantiate their claims with real numbers and real audio files.