CoCostanza
100+ Head-Fier
Check the two philips screws on the headband adjuster(the ones connecting the adjustment rod to the headphone cups). My screew on my right side was loose. This meant that the L & R side didn't make the same contact with my head. On the right side i had a big gap on the bottom part. The sound sounded more distant and bass was lacking.
Sounds like my problem. Im gonna check it out and play a little more with the adjustment.
And I still havent tried them with an real amp. That could fix it. Fiio e12as output power is just 0.4W