Samsung Galaxy S4 Sound crackling/distortion with certain headphones?

Anyone having issues with audio crackling/distortion when using headphones?

 It seems with audio volume above 50% using UE600 headphones i get crackling/distortion thats gets worse as i increase volume. I've read other reports of similar audio issues with decent headhpones but not sure what the issue is.

 I tried stock, cx-270 and koss headphones but they don't display the issue.

http://forum.xda-developers.com/showthread.php?t=2258831