Do you know what a 4 dB boost above 7kHz sounds like? That is slightly over the line of a noticeable difference in the frequency spectrum that is less important than the others to music. It doesn't amount to a hill of beans. Plus, the 4dB is a nice smooth line. Simple to correct for with EQ.
Compared to response curves of speakers and headphones and even tube amps, this is as flat as a pancake.