The HD800 needs improvement in the bass. For sennheiser to make a closed back version of the HD800 and not improve the bass, if that’s what they’ve actually done, then I think they made a mistake. By improved I mean more subass and bass. I could see HD800 owners owning both if that’s the case but not both if they sound exactly the same. What could’ve been cool is a closed HD820 with a variable bass dial like the HD 630DB. That way people could tailor the bass to their tastes.