I don't think is the seal, so maybe I'm too sensitive to high frequencies. Sadly, I have don't have another pair to compare and see if mine is defective.
Happened to me once with Brainwvz M5 (I was looking for an upgrade for my M1, which I like lots). I tried them in a physical store and I liked them so I got a pair for a friend as a present. Some months later I bought a pair for me in the Brainwavz online store and... Piercieng highs (D
, even more annoying to what I feel with E107. Since I knew the sounf of M5 and concluded that they were defective (agh), that's what I think my E107 might be broken, too