I don't have a lot of experience with IEMs... I have only owned the Shure E2c, se310, and currently the se530.
Everyone of those IEMs has sounded very thin and weak to me. The se530s are supposed to have the best bass response of them all, and they still, to my ears, sound weak in the bass department.
My current listening: Foobar>Lossless FLAC>USB>Ibasso D4 Mamba dual DAC/AMP>Shure se530.
I should note, I have a good seal using the large black foamies.
Is this how all IEMs are? Am I just used to a fuller sound from larger cans? I was expecting more from the se530s, as they do sometimes retail for close to $500! Lunacy!