[Heiku]

i've listening then now about more than 9 hours but they sound average while i'm gaming, I don't know much about audio terms but i can tell midrange is muddy and bass has too much impact it's annoying, i mean what's wrong with them? What to do? help me

 

[willowbrook]

Do you amplify them or...hd598 is warm in terms of sound signature.

 

[Koolpep]

  i've listening then now about more than 9 hours but they sound average while i'm gaming, I don't know much about audio terms but i can tell midrange is muddy and bass has too much impact it's annoying, i mean what's wrong with them? What to do? help me

That's very odd since the midrange is the clear star of the show for a 598. And you are certainly in the minority calling the bass impact of the 598 "too much", as it's generally not considered to be bassy.
 
Where do you plug them in? Bad adapter (happened to me)....?

 

[mindbomb]

The 598 need low output impedance to sound right. If you use an amp with high output impedance like the bottlehead crack for example, you get +8db at 90hz. Motherboards audio can also have high output impedance.
 
One thing you can do that might help is make sure you set your audio driver to headphone mode. For realtek stuff, that's shown in this picture http://cdn.overclock.net/f/f3/600x470px-LL-f33cbe5e_Capture.PNG