At the H3 meet, three of us, including Jason, noted that Jason's HD800 was pretty darn harsh, even with the Anax mods*. We compared threeunmodded HD800 with Jason's modded HD800 and still noted that Jason's HD800 was harsher and grainier in the treble. It wasn't like these HD800s sounded completely different. Jason's HD800 still sounded like an HD800. Just that it was a little bit worse than the other up in the treble.
To help unravel this mystery, Jason sent his HD800 (along with the review Mjolnir) for testing. It should be noted that the s/n is 16K. It's a newer HD800. Note that measurements are without the dust covers on unless indicated.
So do you guys see anything interesting? I will follow up with measurements from other HD800s.
* These were from the Tyll cutouts using one layer 2mm foam and thinner ring. Note the official Anax mod is different.