Quote:
Originally Posted by
Mauricio 
Assuming the break-in is real, what evidence is there to support the idea that headphones actually sound better rather than worse after break-in?
There isn't, but that tends to be the pattern. I've heard of 2 IEMs get worse with burn in, then better. Dunu Hephaes and Aurisonics ASG-1.
I believe in lots of forms of burn in: mechanical, tip/cushion, psychological, etc. the main reason I think headphones tend to sound better with time is that the cushions/tips tend to seal better with your ear or head with time. This better deal can only (normally) lead to a better fit which normally will lead to a better sound.