A common issue I run into a lot is, what to set your gain knob at when you’re recording. A lot of people on the internet tend to set their gain a bit too high, or way too high and run into the issue of digitally clipping. The gain knob is a really sensitive thing and can be used correctly if you know a few simple ideas.
If you want to know exactly what to set your volume at when recording, it’s going to be about -12db to about -6db. That means your highest peaks will reach those numbers, that gives you 6 - 12 decibels of headroom to get a little louder, so you won’t peak above 0db. If you want to learn a little more about gain and what it is and why you need to set it at those levels, stick around I will explain more.
What is Gain?
Gain is basically the amount of volume you are artificially adding to your recording. The mic records natively at a very low volume (around -50db to -30db) which is problematic when you try and raise the volume that much in post (I’ll go over that in a little bit). So gain helps bring the overall volume of the microphone up before it gets to the DAW, without increasing the noise floor too much.
Noise Floor
The noise floor is the audio being picked up when everything else is completely silent. When you have your gain set too high, you will pick up every little sound that is happening in the background. Which means the noise floor will be much higher than it should be and you’ll hear a bunch of distracting background information when you are trying to pay attention to the actual content being created. So ideally you would want your noise floor as close to 0 as you can get it, where there is absolutely no noise happening when there is complete silence. It’s really hard to get that outcome, especially if you don’t have a specific room that you record in, and don’t have any sound treatment on the walls.
Distance From Microphone
Where the sound source is located, and how far away it is from the mic is a big factor in finding out what you’re gain should be set at. The farther away you are from the microphone, the harder the microphone will have to work to pick up the source, so the gain knob will have to be turned up accordingly. It’s not a great idea to be far away from the microphone because the sound you are trying to capture will become more and more indistinguishable from the noise floor.
Therefore, when you crank the gain knob, it will not only turn up the sound you are trying to record, but also the stuff you are not trying to record. Vice versa, if you are too close to the microphone, you will have to turn down the gain knob by quite a bit. So keep yourself at an appropriate distance from the microphone, and find the right spot to set your gain at (around -12db to -6db).
Preamp
There are always 3 things you need to record audio into a computer. A microphone, a preamp, and an audio-to-digital converter. If you think you don’t have any of those, trust me, you do. If you have a USB mic the last two are built right into the microphone, if you have an audio interface, or a mixer, the last two are built into those. A preamp raises the volume of the microphone to an appropriate level that you can hear and understand, without distorting the sound as much as cranking the gain would. The better the preamp in your set up, the less you will have to rely on your gain knob to get the correct volume.
Loudness of Sound Source
The last variable is the loudness of whatever you are recording. This is a pretty simple concept so I won’t go too much into it. If you are recording a podcast and you are a naturally loud speaker, you might want to turn the gain down a little further instead of backing away from the mic. Remember, when your recording is going into the computer, you want the levels to be around -12db to -6db at the peaks, so if you are speaking very loudly 5 to 6 inches away from the mic, you will have to turn the gain way down, compared to someone who is a soft speaker at the same distance.
If you made it this far, consider reaching out to me at matt@ieditpodcasts.com to chat about great and creative ways to improve your podcast, or if you would like some help with your entire podcasting process, including launching your show, consultations, editing, or just a more personal conversation!