Sorry for adding so many comments. I always find something else to try out.
The default setting in pavucontrol (that I get after deleting ~/.pulse) is 71% for the left/right front/back satellites, 63% for front and subwoofer. When unlocking the separate channels, driving one up to 100% (& getting noise) and resetting it back to the original 71%, the noise is still there.
Sorry for adding so many comments. I always find something else to try out.
The default setting in pavucontrol (that I get after deleting ~/.pulse) is 71% for the left/right front/back satellites, 63% for front and subwoofer. When unlocking the separate channels, driving one up to 100% (& getting noise) and resetting it back to the original 71%, the noise is still there.