Controlling Background Noise with Your Recording Environment and OBS Plugins

Back in 2015, I wrote a lengthy article regarding my technique to recording excellent training content. Over the past five years, I have learned quite a few new things about audio, which I wanted to share here.

Audio Recording Setup

Before we get too far ahead, I wanted to start by sharing some details about my audio recording setup. Here’s what it looks like visually.

Diagram of my audio-visual recording setup

Microphone Positioning

The position of your microphone makes a huge difference in your recording quality. A good microphone will not make up for a poorly-placed microphone.

  1. Make sure the microphone is pointing towards your mouth. Cardioid microphones have a “front” and “sides,” so you’ll want to make sure you’re talking “into” the front of the microphone.
  2. Reduce distance between your mouth and the microphone. When I’m recording video training for software developers, I typically keep the microphone less than 4 inches away. This will vary depending on your specific setup, but less is generally better.
  3. Avoid placing the microphone directly in front of your mouth. If you talk directly into the microphone, you risk generating “pops” from harsh “t” and “p” sounds. For example, consider the word “paper” where each of the two “p” consonants generate a lot of wind. You can reduce the impact of pops by using a pop filter. My personal preference has been to eliminate a pop filter. They takes up space and force extra distance between you and the microphone.
  4. Speak above, or to the side of the microphone. It might sound like this conflicts with point #1, but it doesn’t. You want the microphone to point towards your mouth, however that doesn’t mean you should speak directly into it. Speaking over, or to the side, will help to avoid pops.

If you are a man with a lengthy beard, such as mine, you might find that your beard gets stuck in the microphone occasionally. Unfortunately, I don’t have a great solution for this. You could try using a foam cover on the microphone, although I like to minimize accessories. I should probably spend some time experimenting with positioning the microphone to the side, instead of below my head.

Volume Levels

Aside from choosing a good microphone, you’ll want to control your recording level. Reverberation (echo) from your environment is a common audio recording flaw. To solve for this, you’ll generally want to keep your audio recording levels low. This helps prevent the microphone from picking up unwanted noise. You can always raise the volume level in your video editing software later on.

For my specific environment, I keep the gain on the Blue Icicle’s physical knob at about 70%. Because it’s an analog control, I can’t say precisely where the setting is at. In Windows 10, I set the recording volume for the Blue Icicle input between 40-50%. In OBS, I reduce the gain on the Blue Icicle input about 2 – 3 decibels.

Volume levels in Windows 10 and on the Blue Icicle

Recording Software Plugins

One of the biggest boosts to my audio quality came from using Open Broadcaster Studio (OBS) to record my content.

Previously I had been using Camtasia to record my screen, webcam, and microphone as separate streams. This separation gave me a lot of power to modify the content in post-production editing. Unfortunately, Camtasia lacks a plug-in architecture that allows you to inject middleware into your audio-video pipeline.

Now that I’ve switched over to using OBS, I can use the built-in plugins and third-party plugins. I recently published an article that talks about using the free ReaFir plugin from Cockos, to reduce unwanted background noises.

Here’s a screenshot of what my audio pipeline looks like. The filters with the eye greyed / crossed out are disabled. This is a convenient feature in OBS, to be able to enable / disable filters without actually removing their settings.

Let’s talk about each of the filters in a bit more depth.

Noise Gate

This is one of the most important filters to use in your audio pipeline. Noise gates work by silencing all audio that falls below a particular decibel level. When you’re not talking, you don’t want the ambient noise of your environment to be captured by the microphone. The noise gate solves this for you.

While default settings may work out for you, you should tweak the Open Threshold and Close Threshold. Basically, the noise gate will stay closed until the decibel level reaches the Open Threshold. The noise gate will continue to stay open until sound goes below the Close Threshold. You should always keep the Close Threshold several decibels below the Open Threshold.

Compressor

The compressor is more of a safety net than anything else. My understanding of how it works, is that if your input audio exceeds the Threshold setting, then the Compressor will kick in and suppress the loudest frequencies.

Your biggest takeaway here is that using a compressor will help prevent audio clipping. Audio clipping happens when your input audio exceeds 0 decibels, and you get a static-like sound. If you have a tendency to shout or get excited about certain topics, then a compressor will save your audio.

In general, you should keep the Threshold setting of the compressor on the higher side. You most likely don’t want the compressor to kick in unnecessarily.

Noise Suppression

Another one of the built-in OBS plugins is simply called “Noise Suppression.” While its name is self-explanatory, it also has a simple configuration. There’s only one setting to worry about: Suppression Level.

If you set the Suppression Level setting to a nominal value, such as -5 to -8 db, you can eliminate much of the background line noise that’s present in your environment.

What Should YOU Do?

Okay, that’s enough talk about my setup. Let’s talk about you now.

What challenges are you facing with audio (and video) recording quality? Leave a comment and let me know what I can help with! I’d love to hear your thoughts on the techniques I’ve outlined above. If your audio quality improve through using these plugins, leave a comment and let me know what worked for you!