HDMI audio from the Pi is fine. It’s analogue audio from the 3.5mm TRRS connector where the sound quality is poor, quiet and hissy. I first discovered how bad

HDMI audio from the Pi is fine. It’s analogue audio from the 3.5mm TRRS connector where the sound quality is poor, quiet and hissy. I first discovered how bad it was building a bespoke car stereo out of a Raspberry Pi 1 - and ended up buying a USB DAC because of it. But it seems to still be an issue even in the later boards because emulation forums are often talking about using HDMI or an addon board for RGB+Stereo if your display doesn’t support HDMI.