I just managed to get the audio stack of my windows 10 more professional with equalizer and VST plugins:
First I installed virtual audio cable and voicemeeter potato:
With those I am able to split up all my audio sources and manage volumes per channel or add equalizers. With OBS you can install the voicemeeter plugin from https://obsproject.com/forum/resources/obs-voicemeeter.741/
Just disable all audio in the OBS settings and add Voicemeeter sources instead. You should use scene inheritance so that you don’t have to do that for every scene. With insert input sources you can grab the input from every input line of potato directly. You could then add VST plugins for every channel directly in OBS. If you want to use equalizers or plugins from potato – or change volumes there – then you need to grab the output instead and route the channel to single hardware/virtual outputs.
Next I took care of my microphone and installed equalizer APO from https://sourceforge.net/projects/equalizerapo/.