Luisdent, I think our different sources may be the explanation. As you mention Accudio a few times, am I correct in assuming you are using an iPod Touch or iPhone? Accudio is a terrific app and a great way to get most any IEM or phone to sound like your preferred phone so long as you listen to an iDevice unamped.
I recently purchased an iBasso DX100 and this has a far wider and consistent frequency spectrum than my iPhone 5 which I now rarely use for music. I never need to EQ my W4s or current crop of earphones with this DAP. But now all my phones sound either warm or dull out of the iPhone by comparison. And on the DX, my Shure 535s sound way too bright and the Limited Edition red ones are fatiguing now but the W4s just right. Probably sell both my Shures soon.
Anyhow, for the OP, I think this just emphasises my earlier comment that you will possibly go through a few different IEMs before you find the ones you like best for no other reason than everyone's ears and preferences are different and opinions are subjective.
That is interesting. If it sounds that much better on the dx100 that's cool. But have you compared it to accudio on the iphone using the hifi setting? I'm curious how that compares. I actually prefer the senn hd600 simulation. It tames the "hi-fi" settings brightness a bit. The hi-fi seems a tad too bright. Even their graph shows that they don't tame the treble spike all the way. ANyhow, want to send me your ibasso? :-) haha. I might have an o2 soon, so I'll see how that changes things... Either way, I think everyone should try to audition the 4r on their device if possible, as impedance and other factors play a role in the final quality.
Edited by luisdent - 2/10/13 at 10:19pm