Ok, so audiophile isn't the right word considering i'm a grad student on a budget who's only experimented with CMOY amps (thinking of a RSA Tomahawk) but I feel as though I have a good ear for what sounds good and what doesn't.  The Shure e500 cans need no introduction as they are at the top of the heap in Shure's lineup of high-quality IEM's (name changed to SE530 but only packaging different.).  I've owned a pair of E3c's before the e500's and I was immediately impressed with them compared to a pair of Sennheiser 595's I had in the past.  From that point on, I was stuck on IEM's as my main form of high quality headphones.  Some say there is always something lacking from a pair of in-ear-monitors, usually depth of sound, soundstage, bass, etc but the shure e500 delivers on each and every one of these. 

I'll start with the negative to get it out of the way.  The e500 doesn't possess the soundstage of a pair of AKG's, Beyerdyamics, or Grado's because frankly, the design of the IEM limits the possibility of that airy sound these cans possess.  That is not to say the e500 does not have a dynamic soundstage. For an IEM, it will give any over-ear can a run for it's money and only those who have heard countless headphones would be able to pick out the minutiae.  What they do possess is an amazing ability to single out individual instruments and place them in their own section of your listening field.  Some songs just send shivers down your spine as they sound so real you almost have to look around and realize that you're not at a concert.  Acoustic, Jazz, classical, and vocals all come to mind in this regard.  Their ability to replicate mid-bass is unparalleled in their class and the lows are absolutely amazing from this little ear phone.  Bass is neither boomy or uncontrolled but instead tight and quite deep.  Everything just sounds very accurate from these phones and sound doesn't seem too colored or messed with (Bose Triports come to mind). 

One caution with these phones is not to wear them while jogging outside as they almost completely block out all ambient noise.  I once had a near-death experience when a car came whooshing by me while I was totally unaware.  Stick with rides on the train or sitting at a desk or at home. I can turn an air condition on in my room, sit next to it and not hear any noise from the air and am almost startled when I take the earphones off at how loud it is.  This is one thing open-air phones cannot match as they may often do the opposite and emit noise into the environment. 

Do IEM's make some sacrifices? Of course but in the case of the e500's, the triple drivers, sound isolation, and low impedence make these the perfect addition to an ipod or other portable device.  While they don't need an amp to deliver the full rich sound, somewhere down the line I will experiment with one to push the e500 to the limit of it's audio reproduction capability. A full review by someone much more well versed in the world of audiophile equipment can be found at www.head-fi.org which is the premier site for all things audio related.