Why not try the Beyer t70p. It receives some mixed opinions thoug. I compared them several times with the NAD HP50. HP50 was my favourite until I listen to classical music, specially violins. It sounded nothing like violins. On the other hand the t70p sounded as I expected instruments to sound, including fantastisk resolution. I have played the violin 45 years. It might also mean that my hearing abilities has worsened though :)
But comparing live sound with the one yhou get out of a pair of head phones are important if you want "fidelity". I you are able to visit a friend's home reccording studio - well, some few really have that, myself also - compare the live sound during recording with the monitoring sound into the head phones. Next, compare the final mix from the near field monitors with the head phones. If you can do this, you will probably be surprised with what these comparisons yields. To me, the HP50 coloured the sound to much for me, the t70p sounded much like the near-field loudspeakers. You wanted "neutral" sound. I think this is a revealing audition to do. This way you compare the live sund and the mixed down sound with what the head phones provides.
If you cannot make possible an audion like this, why not look around and find a recording studio and ask if you can make a visit. Probably they will say "yes" :)
Or you canask around here to find out impressions from a scenario like above.
Best of luck