Per the title, I'm interested in your opinions on which earphone I should look at for a similar sound signature as my SE215 or HJE900, but with superior sound stage. I recently had a sound stage revelation when my friend let me listen to his GR07 (the width was incredible!) I never really knew exactly what to look for in terms of good sound stage until I heard those on the right track.
I love my SE215 (both limited edition and regulars), but the sound stage is lacking. I also have the HJE900 which are more resolving than the Shures, which I like at times, but soundstage is still just OK. I like my bass to extend LOW and my treble to be well-extended also, but not fatigue-inducing. The HJE900 and 3.Ai are right on the verge of what I can tolerate. I prefer something in the line of the W4 for treble response. Basically I want well-extended (and emphasized) bass, nice, neutral midrange, and well-extended, but non-fatiguing treble with the best sound stage possible.
Maybe I just need to try some nice open cans, but I just don't know if I like the way most cans sound for some reason. The search never ends!