Weird audio bug?

[flyntnuka]

Hello. I was hoping to find some answers to a problem I have run into regarding the way obs captures audio.

I use obs very frequently whether it be streaming, recording, etc. And I have always used the default settings when it comes to recording sources of audio.
I use the Desktop Audio Default to record desktop applications, Default Mic/Aux for microphone audio, nothing outstanding aside from having a separate audio source for Elgato.

I do not know when this started happening, but about around the start of 2023, I began to notice that any audio that I record from the desktop, whether it be for a general all desktop source or numerous separated application sources, my audio would be echo-ey. Like when there is a double playback from two separate sources recording at the same time type of echo.
The only problem is that I know for dang sure that there aren't two sources recording/picking up the audio at the same time.
So I look up tutorial videos on how to change specific audio settings, stuff like setting global output devices, audio encoders for recording, etc. None of it works. The echo is still there.
Then I get this weird idea to unplug my headphones from my computer and trying to record something. (for reference, I use a pair of K-ZSN Pro IEM's as my audio listening devices, don't know if that's relevant or not, just wanna be sure)
And sure enough, that gets rid of the echo. Like it just didn't exist anymore. So I replug them back in and start fiddling with my computers sound systems, and I find out pretty quickly that if I mute my systems output to my headphones, but not the output to whatever sources OBS is recording, the echo goes away. But as soon as I turn my headphone output back on, Boom, desktop audio echo.
I've tested this with game audio, opera and chrome browser audio, discord audio, just about any desktop application that plays a sound I have tried gives me the same result.

So I've come to ask for help as someone who isn't the most knowledgeable about how audio systems work for any advice on how to potentially fix this. The only "practical" solution I have come up with is to disable my headphones as a source in whatever application I'm using and listen to the audio through the Monitor and Output function in OBS's audio mixer, though I would like to not need to do this as it's almost impossible to do in many of the games that I play.

Any and all help would be appreciated! Thanks.

 

[AaronD]

I have always used the default settings when it comes to recording sources of audio.

DON'T!!!

Default defers the choice of device to the operating system, which can change it without warning, even while you're using it. The idea is that you plug in a new device, and you must therefore want to use it, so the OS makes that switch. But that's indistinguishable from something that provides an audio service (possibly among other things), and also goes to sleep and wakes up. That is also a disconnection/connection event, and can cause the OS to yank your connections around.

Always choose a specific device, never use Default. Default is only to show, fresh out of the box, that *something* works, and the OS choice is a good way to do that. For everything else, DON'T use Default!

I use the Desktop Audio Default to record desktop applications

The only problem is that I know for dang sure that there aren't two sources recording/picking up the audio at the same time.

Yes you do. If you Monitor something, it goes out the device that you specify in the Audio Settings (or the OS choice for Default). It then mixes with everything else that goes to that device, and then that mix comes in through the Desktop Audio source that is connected to that same device. Now you have two sources for the same audio, delayed slightly because of Windows' buffering, so you can hear it as two separate things.