I recently got the sennheier ie80 as a christmas gift, and these are my first truly high end headphones. However after using them for a day I am disappointed with their performance. To begin with, i can't seem to get a good seal and when I do the iem's will become loose. The bass response is not all that big that I have read in the reviews unless i were to push them against my ears and the treble is similar to that of the beats tour that I had before returning. Keep in mind that I bought these directly from sennheiser so there is no way that my iem's are fake and my source is a Sony E Series Walkman NWZ-E474 and most of my songs are 320kbps MP3 and no FLAC. So I would like to know if these problems are due to the iem's requiring a burn in period or having bad eartips or just putting them on incorrectly. I put them on over ear. I am considering buying monster gel and foam supertips so could these tips solve this problem? Thanks everyone in advance!