What I mean by that is that most “neutral” headphones are going to sound brighter/more treble-focused than 99 percent of consumer audio gear. I try to keep in mind that most of my readers aren’t going to be intimately familiar with every niche headphone out there, but they probably know what Beats sound like.
Most popular headphones are tuned to have a warm, bass-focused sound signature, thanks to the extreme success of Beats. If you switch from that type of sound to a flatter headphone, it’s going to feel at first like you’re getting punched in the face by treble. More and more people are making that switch out of curiosity, and the 9500 is a pretty popular, cheap “First open back” headphone.
The SHP9500 has a slightly cold, slightly clinical character with hardly any bass emphasis, and that lack of bass emphasis naturally makes the treble stand out. If you’re already used to other “neutral” headphones, or colder, brighter headphones, then it’ll be fine.
That’s all I was saying.
Also, the concept of what “neutral” is can vary a bit from person to person, which is why I keep putting it in quotes. A headphone that’s tuned to be objectively flat wouldn’t sound flat to our ears because of peaks and dips in the way our brain and ears process audio.
That’s why we have the idea of compensation curves, a term you might see thrown out there online if you read articles about objective measurements. Most “Neutral” headphones are trying to target one of a few popular compensation curves, which are sound signatures that are designed to make headphones mimic the way accurate speakers in a nice room sound to our ears.
This usually means having some sort of gentle bass emphasis and some gentle peaks and valleys in the treble, depending on the curve you’re looking at. My personal favorite curve is the Diffuse Field compensation curve, which Beyerdynamic tuned their DT770 headphones with. The Harman Target Compensation Curve is also pretty popular.
I don’t think the SHP9500 has overly-boosted treble, but the open-backed design means the bass extension and punch are both laid back. Thus, the treble sticks out more.
Thanks for reading and for the question!