Okay I have been listening to the hd600 with cardas for the past 2 days. I must say it’s a quite an enjoyable headphone that sounds warm, smooth and with decent clarity though not as clear as my other cans. They are keepers but won't be my favorite. Sometimes the hd600 can have abit sub woofish kind of bass which I don't quite like.
For vocal wise, the male vocal sounds pretty rich and female ones sound pretty sweet but not as good/intimate as akgs', especially on Japanese female singers whose vocal often hit the high notes ( screaming at the top of their lungs at such high notes that will shatter any mirror around).
I must highlight that piano sound pretty good with the hd600. I don’t know about other instruments but I often notice the piano part while listening to the senn.
For the fun of it , I tried the headphone on Tool, Michael Jackson, Prince and Metallica. Surprisingly, Tool sounds very good on the hd600 but for the guitar part, it sound abit too smooth, rs1 is clearly better on the guitar part.
Hd600’s warmish sound signature is also very enjoyable for fast paced (maybe not so well recorded) pop music where K501 can be tiring to listen to.
For those hd600 users who want to try the akg k701, you have to expect some pros and cons
Pros- Better and clearer vocals for female
Cons- Male vocal sound less meaty
Pros- Leaner but more accurate bass
Cons- because of the leaner bass, it may not sound as good to you on fast paced pop music (I still enjoy the k701 more)
Pros- More engaging, sounds better at lower level
Cons-more engaging means you may not be able to listen to them as long as hd600 without getting tired. (Depending on your recording)
Pros-Having both cans can cover all range of music
Cons- They are quite different so adapting to one may be difficult after spending some time with another.
List of music I prefer on each headphone:
K701: Jpop in general, Metallica, Prince, any female vocal oriented album
Hd600: MJ, Tool, dance track,