I have those phones and they do need EQing alot. The driver is top notch: no distortion, perfect impulse response etc. Apart from soundstage and no 20-30Hz bass, you can't get better.
The problem is that they are designed with a particular audio theory (diffuse field vs free-field) and that requires a hump at around 3000Hz. they claim on their site that the perceived audio is flat, but it isn't. You can quite clearly hear it using a tone generator. On their graph (see here) it looks like 10dbs, but my tests put it at about 5dbs at normal listening volume (these things vary with volume). The latest research effectively shows that they plumped for the wrong theory, and that's quite apart from the fact that we can hear the hump any way. And there are other artifacts also. My own careful tone listening got me the folowing equalisation:
130Hz -3.5db q=2.8 bw=0.5
650Hz -4.5db q=2.8 bw=0.5
2900Hz -5db q=1.4 bw=1
MASSIVELY improved audio!!!! You get all the benefit of the driver without the expense of going JH16 or UE etc, although those would get you low bass and soundstage.
(also, YMMV canal resonance, grey triples: 8500Hz -8db q=4.8 bw=0.3, best to tune that with a tone generator however)
For the iphone I use the Accudio parametric EQ app, which has a free version with which you can test this. The "thin air" of the stock etymotics goes away. It's a beautiful thing.
However, you may still need an amp. The reason is that iphones don't have much power in their little amps. I think it's .25V max for yours. A clip+ or fuze v1 has .5V which is just enough except for some high DR music (classical, jazz).
With those equalisations you may find you aren't getting the volume. Furthermore, since the etymotics have a weak low end, and since the ears perception of bass drops with lower volume, if you use the EQ to compensate, such as my preference of :
40Hz 5db q=1.4 bw=1
...then the EQ app will lower overall volume by 5dbs, which is a lot. So to get that really good bass you may need the FIIO E5, which apart from a tiny bit of noise, is a basically hifi headphone amp, and very cheap.
Because bass tends to be weak and because every person has a different listening volume that they prefer (also not forgetting quiet vs loud listeners), it's really mandetory to have bass adjustment. People who settle for whatever their phones give them are cheating themselves. The human ear's perception of volume is dynamic and so you must adjust.
All in all, properly EQ'd you have a bargain on your hands.
Hope that helps.
Edited by theequalizer - 12/17/13 at 2:35pm