Since I got my Ipod Classic last year I have tried several pairs of IEM's (Bose, Shure, Sennheiser and Klipsch) to get better sound, more volume, bass, etc. Think I now have my answer.
Just received a pair of Ultimate Ears Super.fi 3 studio IEM's. Left them connected to my hi-fi for a few days to burn in and finallly used them with my Ipod (EU model) today.
I found that the twin flanged tips fitted me better, offering far better isolation than my old Shure E2c's. Could not hear of any of my fellow commuters on the train this morning. Because of this I no longer have to have the volume on the Ipod turned up to the max. Had it on about 50% volume and the sound was clear, detailed and plenty loud enough. Bass is tight but is more heard than felt which is not a problem for me but if you like bass heavy music you may need to look elsewhere. I listen to mainly Indie, Alternative, Alt Country and they sounded great with Apple Lossless files.
Had them in for about four hours and almost forgot they were there. Very comfortable and for £50, a bit of a bargain.