I have heard that metallic bit aswell on couple of occasions. Im suspecting that this is caused by that 7khz peak more than mids. its the one one the thing keeping me from going custom. But my time with supermoon was limited...The bass of the Supermoon is wonderful. This is Campfire Audio we're talking about and it's clear that tuning the bass was a dominant factor in the development of this IEM. It's impactful, nimble, quick and satisfying with enough heft and oomph to win over some of the more ardent DD lovers out there (cough cough @gLer cough cough). The comments about something funny in the upper mids-- be it glare or metallic timbre-- are valid. It could be a library or source thing. I have definitely heard a little something here and there though it crops up for me very infrequently. People who are fixated on a really analogue timbre might not be best suited to the Supermoon. It's very high res sound and I while I understand the comment about them having a "digital" flavor to the timbre the sound is quite natural sounding to my ears. The resolution and coherence of the Supermoon is off the charts good. I never fully understood what was meant by either term until I heard this IEM. It was a transformative experience for me in this hobby.
So i will need to analize it better soon