I checked https://www.elgato.com/en/gaming/game-capture-hd60-s-plus but it doesn't mention anything about audio. Try setting your PS4 audio settings to Stereo 2.0 . ¯\_(ツ)_/¯ I have neither PS4 or Elgato. Just a guess.
You can absolutely set your audio output in the PS4 system options. Most likely, your capture device is claiming to have 5.1, 7.1, or other surround capability. A quick Google search for 'ps4 set sound to stereo':Back to trying this again and still struggling. I've got a great mic sound but I'm frustrated with my ps4 audio. Anyone able to help with settings from square one, tweeks on OBS etc? I'm getting a PS5 soon too, so let me know if the settings are different.
Thanks
You want to disable everything other than Stereo (Linear PCM).You can set the format of audio output from the PS4 system. Select Sound and Screen > Audio Output Settings > Audio Format (Priority).