[Velocity]

Quote:

I've heard that the 600s are more harsh than the 650s, is that true. I want the sound as smooth as possible.

Where did you hear that?
I owned both HD600&650, powered them with M1 HPA and I can comfirm that HD600 is no more harsh than HD650. 
Even mention HD 600 or 650 and "harsh" in same sentence doesnt really fit. 
 
Actually I would say HD 600 being smoother than HD 650 in way of being more transparent and more natural. 

 

[JonasRas]

Thanks for the help guys! I've decided to go with the 650s Because i think they will fit me the best.