E-q5 have a
very different frequency signature than the monitor class audio technica ath-m50 .The e-Q5's dominant highs don't make them suitable for studio music production like the ath-m50, unless your sensitivity to high freq isn't so sensitive or maybe some just prefer a brighter than "natural" sound .
Earsonic SM3 are the closest "similar sound" to the ath-m50 that I've heard ( I do own some M50's ,though because of design I use mainly the HD25's), The SM3's don't have the bass impact of the ath-m50.Though the SM3's have sufficient low & high extension .
SM3's could be used as studio monitors like the ath-m50, provided the ear was attuned to less bass impact than a Decent Good quality full size headphone, as is the case with ALL I.E.M's .
Just bear in mind when listening to a I.E.M & comparing them to a headphone sound, that you can get some similar sound characteristics, frequency range being one of them,but you won't get other headphone sound characteristics like bass impact/conductive vibration.
I.E.M's have characteristics that full size headphones don't have . The close "connected" or in the head sound that I.E.M's can provide can also give a extremely focused & detailed sound stage.
Some speak of hearing music like your sitting on the front stage ,some like your playing in the band .
I like to hear music like ....I AM THE MUSIC .
Well I'm certainly made from the same kinda 'stuff' .