Not sure if someone can confirm my observation, Sibilance is very noticeable on some tracks (not exhaustive, I just hit this track on my tidal radio mix) -e.g. JFK by Ryann. Very pronounced, not sure if someone can confirm? And maybe it’s my sensitivity on high note - as I heard some other tracks having a very high “bat sound” pitch. If you lived in rural area, you can relate on this sound. Trying to find those tracks and will share. I also compared with another FH7 in the store... I believe I dont have a dud or manufacturing quality issue, it’s just how it sounds as the store one vs my FH7, very similar except mine is less sibilance based on my setup (i.e. Memory Foam + Green filter) vs the shop one (stock black + black filter). Maybe better fit.
Over-all love this thing! - also tried today to compare with Shure 535 Red Colour edition (supposed to sound better than regular Shure as what the sales told me) but still, by far - build and sound quality FH7 wins, no doubt on my personal novice hearing and standards.
Again - these are my very own personal and practical view
(e.g. actual bat sound heard, not vs on other IEM sound comparison lolz)
Hope above helps other folks with some more info stuff they can refer.