Really good and it goes really loud. It's like having speakers strapped to your head.
The mic is great too. I just tested it and was knock over by how good it is. The fact you can unplug it is great and when adjusting the stem of the mic you can feel how sturdy it is.
I have read reviews that say that it is too tight on the head and at first I was surprised at how tight (I prefer the term "snug") they actually are. They are very snug and cause me no discomfort whatsoever. Mmmm velvet ear surrounds!!!
I have to give this 5 out of 5... For the money this headset costs it give exceptional audio quality, great mic, comfortable and comes with a nice little carry case too!