Well, the A161P is one – it’s a more aggressive sound but it also has better imaging and more bass. The deep bass is especially more prominent compared to the A151.
Another one in a similar price range is the HiFiMan RE-400. It doesn't have a whole lot more bass depth than the A151 but it has slightly more mid-bass impact, along with very smooth mids and treble and a well-rounded presentation.
Along those same lines, the Philips Fidelio S1/S2 have more deep bass than the RE-400 but also are a little more energetic in the treble region. They have wider soundstages but lack the layering of the RE-400 and VSonic GR07.
The VSonic GR07 has more bass and a wider soundstage and doesn’t really give anything up except for the treble smoothness of the A151 (although the A151 doesn't have quite enough treble energy in my opinion).
The UE900, if you really want to spend a lot, has smoother treble than the GR07 and fits all of your other requirements.
Thanks Joker. With those recommendations in mind, do you think i might get comfort issues with some of them? I guess i've a small ears, because A151 is pretty small IEM and it still gets uncomfortable after some time wearing it over the ear - it pushes on my antihelix and start hurting there. Maybe it's just A151 shape, but i still only use them with small to medium tips since my ear canals are quite narrow.
Edited by iRo-Fi - 7/3/13 at 2:53am