You could always do a sinewave sweep and hear for yourself if you could hear that spike.

I know with the HE-400s, even though it has a huge upper-treble peak peaking around 14kHz with purrin's measurements, my ears tell me that there is a peak at 8kHz, and then another lesser peak at 12kHz, then a gradual roll-off, with sinewave sweeps and my ears.

There's too much variance in hearing sensitivity between individuals in the upper treble frequencies to really trust FR measurements there.