OK, time to clear things up. I hammered these about 3-4 months ago, a number of times.
Some of what I said is still true - for instance the claim that the HE-6 and the HE6se are the same, that's rubbish, I pointed out the 8-9 ways that they are physically different which has a distinct impression on the sound. It's an intractable truth.
My mistake was confusing my low VAC (114 during my 1st time with this headphone). At the same time my HD-600 and HEX v2 showed no signs of trouble with the VAC, although my HE-500 did show some, and for a time I had my HEX v2 rated ahead of my 500's. I ended up packing up and shipping off my 6se, but the buyer wasn't happy, so they came back and I tossed them in a corner. Then a month ago my VAC went to dead-on 120, and my HE-500 started sounding a lot better. Hmm. My amp, DAC, or CD player? Tough to reproduce the problem with text book current coming in. A VARIAC is far too dirty/noisy to be reliable a tool. Besides - who cares? It's better.
Then I got TIDAL Hi-Res through an LG V40, and no more CD player, I let the 6se out of jail, and oh my, still bright in the lower treble, still a dip in the upper mids, but the fabric of the sound and detail was more than good enough to continue listening. Using the toneboosters EQ and using the graph from 11/18/19 on that other site (seems the closest) and a few previously annoying CD's as guides - and it proves: that that is a good EQ tool, and that as of now these are the best sounding cans in my collection - although I haven't EQ'd the others yet.
The 500 and 6se are relatives, I wonder if they draw a lot of current which is what makes them sensitive vs the other cans - must be.
Anyhow the HE6se was not then or now worth the original asking price, but at $699 Adorama? Even $899 - it's a good buy. It's not a HE-6, it's a modernized, somewhat homogenized version that if you have the juice, and ability to EQ it, is a worthy addition to a collection.
Sorry that my logical sloppiness may have caused people to alter decisions.