I'm not a huge writer on this board, it may be my first post so hi everyone
I work in a studio (mixing mainly), so I'm very picky about the frequency balance.
I broke my ety's (4s) few months ago
. I decided to make the jump for the e500.
First (like for ety's), a correct sleeve/position/seal is very important and as someone mention before, it might be a reason for some divergence.
E500 and 4s are two different beast.
4s are extremely detailed and very tight. In that sound (detailed and tight), I never heard something comparable (headphones and speakers).
My two problems are the power they require and the lake of bass. I think it's nearly flat but knowing that you miss a part of the low content because you can't really feel it with headphones, it's probably "too" flat (its also a question of taste). Anyway, it's not that they can't go very low, actually they go low and they do it very precisely but this lake of bass can make them sometimes a bit aggressive.
E500 are very enjoyable (pricey though) but you really loose something between 2.5 khz and 7 khz. So you miss a lot of details and you loose the consistency of the sound. I can really hear the woofers and the tweeter working separately (which is often the problem with multi voices). Also the bass being more pronounced you can sometimes loose the low end (being hided by the upper notes).
Being more on the analytical side, I prefer the ety's. However if I want to listen more casually and considering the fact I can easily drive them with a portable rig, I might use the e500 for that purpose.
Just me 2ç