Excerpt: it may be worth paying the $ extra for the HD-650s for the better cable. But the 600s sound excellent and are very comfortable. You might be able to get the same sonic quality for less but not with the nice ear pads I suspect.
Summary: These are very good headphones for the money, quite balanced sounding. Yes there are some headphones which can do this and that better technically, but somehow not as balanced overall and not as natural in the midrange. For instance the HD-250 Linear II that I reviewed earlier and still use has better extension at the top and bottom, faster transients and better depth to the soundstage but suffers from what every closed headphones does to an extent, a bit uneven...
Summary: I am going against the grain I guess. These cans are good, but they don't live up to the hype. The first time I demoed these they were going through a Creek headphone amp and after 20 minutes my ears were ringing. I told the salesman and he thought I was on glue. 6 months later I decided that I must have had a bad day and bought a set. I thought running them through my dedicated tube amp would be magic. Wrong, I don't know, I just find them BORING.
Excerpt: I bought these headphones as an upgrade from my Sennheiser HD570, and the sound is much better. They are plugged directly into the audio out of my computer, for music/movies/gaming. I was afraid the high impedance of the HD600 would demand a headphone amplifier, but they work ok without one. Unfortunately the pressure on my ears & head is much higher than the HD570 so I can't say they are as comfortable.
Summary: There have been so many reviews here I almost didnt write one but with the lack of reviews by producers I decided to add one more to the list.
If you're producing audio like myself you already know theres no replacement for a good set of monitors. That said there's a few reasons you may be mixing through a set of cans.
Summary: As a New York recording a mixing engineer I've had the opportunity to listen to quite a few pairs of headphones. The Sennheiser HD600s are the clearest, fullest, and most balanced headphones I've heard so far. While they wouldn't work for a performer in the studio because of the open-air design and considerable leakage, they have become a must-have as a mixing reference, especially when mixing in a new and unfamiliar room.
Summary: The HD600s were my main phones for a few months. I could listen to them for longer than any other phones because of their relaxed presentation and wonderful comfort. They were satisfying phones for classical music until I upgraded to the HE60. (Compared to the HE60) The HD600 the highs are reccessed and lack extention, the bass is not so tight and textured, the sound stage is not well focused... overall the HD600s sounded slowed and even muddy in comparison.
Summary: Construction-wise, the HD-600 is a little delicate. No, the HD-600 is not poorly constructed. Rather the headphone is designed for home use and is meant to be light and comfortable (and comfortable it is). Just don't plan on bringing it on too many bumpy trips. The HD-600 brings out a good degree of texture and details from music and produces a wide soundstage. Treble seems to breathe well though can sound a touch sharp at times.