They sound artificial compared to Senn HD650 tho. I had them both for a while and as I listened to the HD 650 exclusively for like a week, I switched back to compare, and they sounded artificial/thin/lifeless in direct comparison. When you take them by themselves they are really good, but in no way do they compare to the higher end imo.

Natural bass? You should try other higher headphones to realize what the natural basses are. However, the HD598s are really good start headphones for anyone going to the Audiophile world.

I am sorry for what I wrote. You were right but I do not know why the hype of HD598 is too high on many websites included head-fi.org? I had a HD598 before and find out that most of my musics were boring or sleepy on HD598. The HD598 could be the smoothest headphone of Sennheiser's headphones ever created.