This is true. Too bad with all that research they didn't find a way to give it linear frequency response. Its 6 kHz peak is like a sonic drill on my skull. I wonder if that was intentional, to make it sound more "airy" and "detailed", the sonic equivalent of video monitors whose default settings crank up the saturation & contrast to make them grab people's attention when on display in the store. Of course, it's easy enough to fix with EQ. But the 6xx series sounds more linear through the mids & treble without EQ, but they do lack the HD800's soundstage and "air".