I have see some very old threads talking about the exact same issue that I am facing. I have a Sonos Beam with Sub and two Sonos SLs
I have the beam connected to TCL6 series via HDMI arc and TV audio is set to output Dolby Digital.
I am using native roku apps to stream.
When I play YouTube, I get good dialogue volume, Level 20 is good enough and the music and dialog levels seem balanced.
When I play netflix, the sound effects are way too loud in comparison and dialogues are barely audible. To make sense of the dialogues I have to turn up volume to 40 or even higher however that makes the effects too loud. I have to constantly keep adjusting the volume. This is so frustrating.
It almost feels like the center channel is not loud enough in either 3.1 or 5.1 setup. I have tried the Speech Enhancement too, it helps a little but not enough.
I have also tried True Play tuning many times.
Any more ideas?