Hi. Where are the D600s "made in"? China?
Do you think they are sound quality wise on one level with the HFI2400, although they are closed cans and the 2400s are open ones?

Sounds good, I wonder how the compare to the D2000 ?

Would this be a good beats alternative if I pair it up with a fiio e11 or a digizoid zo2?

Have you ever listened to Ultrasone Pro 900? I am trying to decide on my next closed back headphones, and I want something with powerful low-hitting bass. The bad thing I keep hearing about Pro 900's is fatiguing treble. And, I can't find any to listen too in my areas (San Antonio, TX).

The Pro900 has seriously fatiguing treble. I just ordered the Denons.