[glorkaglickflic]

Can you compares IEMs with full-size headphones?  I was wondering if a comparison could be made with the Etymotic ER 4 S and the LCD 2, HE 6, HE 500.  Its really the sound you're comparing.  I think ergonomics might come second, after the sound.  Anyway, I hope some kind of roundup could be done.

 

[squallkiercosa]

A short answer will be no, you can't make a proper comparison due, mostly to perception, coherence and soundstage. Music listened through IEMs is not relaxing side by side against over the ears.
Some IEMs might share a common signature with their full sizes counterparts, but the sound won't be interpreted in the same way precisely for the distances between the drivers and the ear drum.  
 
Hope it helps