@TimeSnow your 'stories' are so laden with errors and inconsistencies, I wouldn't even know where to begin, but I can make an effort.
#1, the 560 is flat in the sub-bass. It's not elevated, or rolled off. We could argue about how it's portrayed (perhaps lacking in slam/rumble/envelopment vs. other brands' planar/dynamic drivers), but that's technicalities of the driver, and besides the point.
Most peoples' brains don't even 'understand' the sub-bass frequencies (until brain-burn in sets in), especially if it's their first planar, and they're used to dynamic cans.
Most speaker setups will not portray sub-bass frequencies accurately due to room acoustics. It's a sort of a revelation to hear sub-bass without standing waves or room resonances.
#2, the distortion comment doesn't make any sense, it doesn't have any basis in science or measurements, nor does your conjecture support your future posts, which seem to vary and contradict themselves.
Most people listen to music from bad sources and bad transducers, and they're certainly not mixed to sound 'horrible' in those.
#3/
#4, different transducers and amps respond to EQ differently, you cannot make generalizations. HE560 responds to EQ well, if you know how to EQ.
Most dynamic drivers' begin to add distortion, especially in the sub-bass region, even if you EQ/"boost" them well under safe limits of clipping. (I won't delve into driving an amp into clipping.)
There's audible distortion in HD650s' sub-bass, but it's pleasant, and that's why it has a "speaker-like" presentation, a lovely imitation of real life IMO.
#5, related to #1, 560 isn't exactly a sub-bass monster 'reference' can. An accessible suggestion would be to try Audeze LCD-series. There is face-melting sub-bass which cannot be achieved by any IEMs,
sic. You could add a Subpac for the placebo effect, but obviously your chest won't be pounding, like with a speaker/sub-setup.
Oh yeah, related to your babbles about open headphones, besides the LCD-XC, they're not closed-back.
#6, once again riddled with contradictions, as
@thebkt said.
Amp has less effect on the sound than the transducer itself.
#7, and related to #6. We have the best transducer technology at this present moment in time, than in any previous time in history. People are listening to music with better gear by the day, and this technology continuously moves forward.
I won't deny that most modern pop records are mastered in a way, that they would sound 'good' ambiguously on many systems. But the fact is that dynamic, 'audiophile'-grade masters are still sought after and appreciated, their popularity has risen in the recent times, and in the future, that's where you can only make your mark, and not with mediocre all-rounders. Ever thought about that?
And another comment: handling sub-bass with Beats or cheap IEMs? That hasn't happened. You're confusing mid-bass with sub-bass. "Reference can" listeners haven't been left out in the cold, as their cans arguable can handle the sub-bass content.
"Reference cans" won't need to adapt, the technology will bring "reference can" sub-bass content every single listener, when the technology gets there. If there's distortion in the crappy pop mix in itself, the solution is not to mask that with crappy driver technology, but to clean up the mix instead, hello?
You're saying that "reference can" listeners are missing content, which is absurd, when in fact they have been revealed what the content is.
No apologies here.
#8. You have got to be kidding me with the dynamic range comment.
http://dr.loudness-war.info/ is so last decade, huh?
