My PC has a 3.5mm analog audio output for headphones or speaker. As such, there's no noise and the sound quality is good.
After adding an audio splitter, I plug my headphone into one of the 3.5 mm jack and that works well, as before.
When I plug in a 3.5 mm connection cable, plugs at both ends, (Bose brand), and plug it into my other PC's audio input,there's "static" [sic] noise all the time. It's like there is some sort of electrical static noise. But on the 3.5mm output of the other PC, if I just wear the headphones there, it's all clear again. ONLY the input is like this.
I have an HDMI recording device that can be added to OBS to capture a console's screen for example, but also to listen to said device's audio. However, if I listen to that in OBS, there is noise. So noise is present when using the digital HDMI signal.
Where is the noise coming from?! I've tried filtering it with Speex filter in OBS for example, but it's far from a solution. It's just a dirty workaround.