Regarding tips, My left ear canal is slightly smaller in circumfrence than my right ear so the large was tending to dislodge out after a few minutes. I switched to medium in left ear and large in right ear which seemed fine.
I tried some dual flange Ultimate Ears tips and these are great! They seem to stay a bit more secure, I can use the same size in both ears and the sound seems identical to the supplied Grado gel tips.
Goodvibes....not sure what player you are using but try a little bit of bass eq or "rock" setting if Ipod product. It's perfect to my ears.