[jellybean1133]

100 hours it is, even after 15, they seem to sound a bit better. however they have a very muddy heck of a thump in the mid bass, i hope that recesses as they warm up. 

 

[Cakensaur]

I bought mine used. mine was still strong but not muddy.. so i assume it goes away with one of two things;
 
Burn-in (not incredibly likely)
 
Amplification (more likely)
 
Enjoy

 

[jellybean1133]

after 70 hours of break in and a fiio e11 with my ipod classic i can say i am overwhelmed with my 770's. build quality is as top as i can ever see with it not being a metal brick, sound quality is superb however even i can see what people mean by a huge lack of midrange and im no huge audiophile myself. overall i like the sound way better then the akg 500's and the highs are much better than my ahd1100's. satisfied customer