[ProtegeManiac]

   
I also have the Sennheiser IE800 that I barely use and think of selling actually. Compared to the Shure SE846 and the UE 18 Pro, the IE800 is a toy. Specially with that awful cable noise it has.

 

Try the same listening you did, but this time with something like an LCD-2 or HE560 - comparing the on-board, the E5, X7, and the WA7. IEMs don't get anything to a point where there is a lot of distortion that it would be easy to tell; if my S3 wasn't driving an IEM with that much bass response that makes it harder for its audio chip to control, I likely wouldn't notice much of a difference. The Fiio X1's real advantage (though no small thing) over my SGS3 is that Samsung's volume control has around eight or ten steps between 0 and full volume, while the Fiio DAP has 100 steps. The SGS3 has less than 10mW at 32ohms, AFAIK, but it can go from "almost there..." to "TURN IT DOWN!!!" with one press; the X1 has around five to eight steps between those two points.

 

[davidsh]

When all is said and done I do think you owe yourself to get a cheap proper amp like O2 territory) and perhaps a decent and cheap DAC too to have a good base and reference.