OBS isn’t made to record audio only files, but you CAN easily create a low bitrate video with Opus audio while keeping OBS push-to-talk and volume controls.
If you want to know more about OBS and video compression in general give this link a go! It’s a little dated now, but it’s got a lot of information. It can also help understand a lot of concepts that go on under the hood. Or you can get more advanced information on current video codecs.
Say you want to record a conversation on Discord. A simple audio recording program will either record your side, or the other side of the conversation, but not both. Open Broadcaster Software (OBS) will pick up both simultaneously, and can pick up more devices if you wish. Stronger audio programs will do this too, but if you’re already dabbling in streaming, chances are you have OBS installed.
Another advantage of OBS is that you can use a feature like push-to-talk. This way your microphone doesn’t record every breath, cough and sneeze during your hour-long conversation. Just set the same push-to-talk key as you use in Discord and you’re all set.
VIDEO: Setting OBS up to record files without any video whatsoever results in a corrupt file as of version 22.0.2 and even with custom muxer settings, it still seems to fail. However there’s nothing that says the video portion can’t be tiny, and even descriptive or decorative. For this example, we will use only 4 kbps for the video, and we will use x264 to encode the H.264 format since at this bitrate, there’s no point squabbling over other codecs and it’s the easiest and most reliable to setup.
AUDIO: Opus audio is easily the best lossy codec in the world. Stereo music sounds fantastic at only 112 kbps, but with a voice-only conversation 64 kbps is more than enough. You could even go lower if you want to, but, since this example assumes we’re recording a Discord conversation, we need to bear in mind that Discord audio is already transmitted through a lossy codec (like Opus) and when we encode it a second time, there’s now 2 stages of losing quality. Going lower than 64 kbps is not recommended for the purposes of this example.
If you don’t have OBS feel free to grab it here. It’s free and open source. Then head to the next page to see the setup screenshots.