High, high treble frequency adjustments, I think you can just pick the one you prefer, most humans can’t hear what these filters do anyway, and if you can, it’s really subtle, probably more subtle than moving your headphones like 2mm, heh.
If you really want to be A U D I O P H I L E about it, there’s something about pushing the distortions at higher than hearing range, and how “bad” filters can introduce distortion under than 20khz therefore into human hearing range. That’s the main argument for hi-res audio too.