A bit of a longshot, but check your EqAPO config if the audio device at the top actually exists. You check this by running the Editor program from the EqAPO root, at the top there could be an error. See also this post.. Hope this helps.
I think I had the same issue then. EqAPO was referring to an non-existing audio device. I could only see the error when opening the Editor, all else looked fine.
This is what fixed it for me. See also this link on the EqAPO forum.
This is what fixed it for me. See also https://sourceforge.net/p/equalizerapo/discussion/general/thread/8b0e5fa8f4/ on the EqAPO forum.
The latest Windows update killed my setup, and I tried all the different troubleshooting options in EqAPO, but for the life of me I could not get EqAPO to do anything. This went on for a few hours until I checked my base EqAPO config (input + Peace + Hesuvi, very simple). There it turned out the playback device was set to a non-existing output device, probably caused by me reinstalling VB-audio cable (needed for Hesuvi) in my journey to fixing the issue. It is a bit of a niche issue I had, but if...
The latest Windows update killed my setup, and I tried all the different troubleshooting options in EqAPO, but for the life of me I could not get EqAPO to do anything. This went on for a few hours until I checked my base EqAPO config (input + Peace + Hesuvi, very simple). There it turned out the playback device was set to a non-existing output device, probably caused by me reinstalling VB-audio cable (needed for Hesuvi) in my journey to fixing the issue. It is a bit of a niche issue I had, but if...
This fixed the issue for me. Note that I bumped my head against the wall for a few hours and could not get anything working, until I check my base EqAPO config (input + Peace + Hesuvi). There it turned out the playback device was set to a non-existing output device, probably caused by me reinstalling VB-audio cable (needed for Hesuvi) in my journey to fixing the issue. It is a bit of a niche issue I had, but if EqAPO seems to be not working at all whatever you do this might be worth a quick check...
The way I have it setup for me is like this: vbcable as main audio device, equalizer apo is installed to that. So hesuvi and peace apply to that only. I use the default windows listening method to pass on the audio from vbcable to my physical audio device. I output my discord audio to my physical device directly, skipping all the virtualisation. This should lead to a echo free experience for discord. This works fine for me. When I listen to music I simply switch hesuvi to stereo manually.