According to what I have found in their studies {Anthem + N.R.C.} they came to the conclusion there isn't much use in EQing past that point 5KHz. {Can you tell I google too much info}

Lot's of people like to adjust to their preferences. Though It's about equal due to Mic. and human hearing.

One article I read from Anthem briefly discusses this topic, where I think they said you can go higher if you like, but their studies found the 5KHz to be most appropriate cutoff point.