I have the Off the Wall album in 24 bit Flac and the track I used for reference was Get On the Floor. Nasally mids make him sound vaguely like he has a cold. It's subtle and it wasn't until I heard this song on the SE Solaris that I really understood what it meant.
I can't really give any specifics because it was too long ago, but I remember thinking "nasal vocals" too when I compared it to the Andromeda S. Not a lot, but enough to make me notice.
Compare with Elear, using DX229, Yes I slightly noticed there's a different male sounding... Quite difficult to distinguish... using MJ - Billie Jean
will try with other DAP and IEM to compare...