@redrol
Given that graphs accurate, Roland appears to be slight departure from DF. About 4db elevation on the low end and smooth come back to 0 @ 1K. It does sound like this to my ears, so with 2 caveats: I got rid of Er4s long time ago, so all I remember is that it was brighter and colder sounding than Roland. On Etys I perceived sub bass to be rolled off and had to EQ (could be due to my longer ear canals, that also caused CL2 to fall short..)
Treble on Etys was chilling cold and bright (similar to Beyer dt990, S8P mids and treble were much warmer). Roland treble is different, more rolled off (again, agree with a graph) but have even less perceived "sparkle".
I'm putting Sparkle in quotes because it's deceptive. I hear instruments (like high hats) on LX with more sparkle and they sound closer on the stage, but on Roland I find them slightly further but with same or !! more detail. I'm still switching back and forth, looking for details that I would miss with Roland, yet find them satisfactory every time.
Roland:
I personally having harder time coming back to LX than back to Roland during those a-b switches. Could be that I'm actually discovering my affinity to neutral/natural sound?
What cable are you using with your LX?