REEL PRO - AUDIO

Home Studios: Choosing the right interface

By Dave Kresl
September 7, 2021

So now we have talked about microphones and set up a small home studio space.

But if the microphone doesn’t have a headphone jack, what do you do? That means you don’t have a USB mic, but one with an XLR connection. You need an interface or preamp, or I/O box.

If you choose a USB mic, you don’t need one.

An interface is a way to power your mic (if it is a condenser type and needs power), amplify the signal to a usable level, convert that signal to digital and send it to your computer, and finally, play it back in your headphones or speakers. I/Os come in many sizes and can have from one to over twenty inputs. Generally, unless you are recording music or doing interviews with more than two people you won’t need more than two inputs.

They vary from brand to brand, but all pretty much do the same thing. The main controls for each channel are, a gain knob, a 48v or phantom power button, and a monitor (or headphone volume) knob. The gain pot, or potentiometer, controls the level of the microphone going into the computer. It has nothing to do with how loud it is in your headphones although the more gain, the louder it gets.

All microphones, like people are unique and require different amounts of level or gain. So one model might need the knob at 12 o’clock and another 3 o’clock for the same apparent volume. One thing about gain is that each preamp has its own sweet spot where the microphone sounds best. If your recording sounds flat or doesn’t have any life, maybe add a little gain.

There is a spot just before distortion, that the sound source feels alive. Make sure, if you have a meter on either your preamp or recording software, that you keep the peaks around -10 to -12db. If your I/O is color based, keep it in the green with the loudest parts in the yellow and try to stay out of the red!

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If your microphone is dynamic it doesn’t need power, but if it is a condenser, the preamp provides power to the capsule or element. It’s either on or off, but it doesn’t hurt a dynamic if left on. Then the volume or monitor knob will control how much you hear in your headphones.

The interface can connect with your computer via USB, Thunderbolt, Ethernet, Firewire… there’s a lot!

Finally, regarding price, you get what you pay for. Like most products in the audio space, quality has skyrocketed. For about one hundred bucks, you can get something that would rival a ten year old product that cost five times more and can do the job for most home studios. If you up the price a bit, you can get professional results that rival the studios.

Dave Kresl has worked as a recording engineer in the Chicago advertising community for over twenty years. Through the recording and mixing of thousands of spots for television radio and internet, he can help you with the process of preparing great sounding auditions!