Hi there,
A while ago I started playing with ZynthianOS + RPI4 using on board sound device (mini-jack). For me the sound was decent.
I’ve already followed some of previously posts, and it seems that hdmi and mini-jack are not very suitable for good sound quality. Even that, I wanted to test hdmi audio output connection.
I want to connect the rpi4 to a soundbar using the hdmi port. The soundbar only supports hdmi and optical inputs.
I’ve selected the audio to hdmi. The sound I get is horrible, it seems saturated.
I might expect some latency, why not, but I was expecting a good sound quality.
I’m stuck, any tip to continue exploring it?
I might end buying one of the DIGI boards 
cheers,