I have questions for you. Do the HD6xx sound the same as the HD650? Are there any closed headphones in the $350 or less price range that would sound as good as the HD650? I'd really like a big sound stage, and flat tonality, as in actually flat all the way down to the sub bass. Not that er4 type "flat" where there is no bass. I also need them to be exceptionally detailed and controlled sounding for the some of the music I listen to, otherwise the sound turns into static mud. Inner Universe from the Stand Alone Complex OST would be a good example of what I need to be... well resolved... I guess that's how I'll put it. Also, pads similar to the Audeze pads or the Dekoni Blue pads would be preferred. They need to be deep.