Probably the dual dynamic drivers give it that nice big soundstage
Have the b3 and the re400, the re400 has a bit more mid bass presence but the b3 extends a bit further down. The b3 does take well to a nice bass boost though. Mids on both are quite equal, the treble I find the b3 to be more forward than the re400. The b3 though truly excel in clarity and with soundstage compared to the re400. The havi I have been finding time to give them a listen while the re400 for me have been hanging around in my drawer for last few months.
very interesting, i was blown away with the re400 as my first over 100$ iem.
the soundstage is the same size as the re400? i actually thought the re400 is just about average in terms of soundstage width, depth was pretty good.
bass boost? haha i'm playing them off my ipod touch, i probably won't touch the eq. but surprisingly even less than the re400? in terms of mid bass? maybe i should get the pro II if anything i guess. but i need to get rid of some of my gear before dropping the money on the b3
edit: 1000th post! yay!!!! =)