Quote: Hmm, curious... perhaps I'm a bit more sensitive to higher frequencies than I originally thought? Quote: Thanks for the update! As for the setting the volume between 3~6, I'd wager that the HD 215 is sensitive enough where those levels start to exceed comfort. Quote: Are you looking for something to be used for critical listening at home, or a pair of closed cans for portability's sake? If it's the latter - and I'd hate to mention it - but I do like the Amperior quite a bit. I AB'd an HD 25-II at the most recent LA Meet against Jude's Amperior. Though some may say that the difference is slight, I could hear a distinct advantage in the Amperior - particularly in terms of speed and detail. I know there's quite a price difference between those two, but for me (personally) it would be worth it. In fact, if anyone from Sennheiser is reading this, I wouldn't mind reviewing the Amperior. As for the HD 558, I really can't say as I haven't heard them. Nor do I have a whole lot of experience with Grados.