Then the HA is not fitted correctly for music.
I used to wear Phonak Naida B with closed soft ear molds. “Tinny” is something completely different compared to my son’s Logitech G935 headset, both attached via bluetooth to the PC. I don’t hear any high frequencies for many years so I can’t tell anything about that. I.e. it highly depends on one’s hearing loss.
It is strongly recommended to post one’s audiogram but @david.hendon (thread starter) still refuses to. So we can’t compare each other. Everyone is different but in this case we can’t even talk about it in theory.
(But keep in mind, this post has nothing to do with real hifi! It’s only the best a man can get)