If you don't believe in burn in and have a few bucks to burn. Buy two pairs of JVC Ha fx1x. Do not listen to them. Burn one in for 5 days at 24 hours a day and leave the other one alone. At the end of the 5 days listen to both of them side by side. You'll notice a big difference between the two. The one that hasn't been touched will have very piercing highs. To me I couldn't listen more than 20 seconds before my ears started hurting. The one that was burned in will sound much smother, at least for a $16 IEM. After the 5 day burn in I did with them (I didn't listen to them during the burn in because the highs were killing me) they didn't hurt my ears and I used them at the gym for between an hour and an hour and 45 min for the next couple of weeks. This confirmed for me that burn in is real.
My source was an un amped iPhone 4 playing lossless files.
Edited by JonnyRocket - 1/29/13 at 9:39pm