In live music, especially acoustic or orchestral works, the tonal balance is the natural product of the character of the instruments and their interaction with the venue (and, of course, precisely where you sit within it). Take a proper recording of that performance and replay it on a neutral setup (e.g. my room-corrected/treated speaker rig) and it maintains the same tonal balance, and instruments/performers maintain the same tonal and presence relationship to each other.
The Harmon Curve(s) are really preference targets rather than an attempt at neutrality. When you apply ones of those to the above situation, lots of things change. For one, the tonal character of the piece shifts … with both low and higher frequency emphasis. This results in, say, a double bass not only masking the lower tones of a cello (as it might naturally do), but potentially overwhelming (or masking) notes all the way into the violin’s range. Similar things occur in the treble.
I find it quite unnatural, though granted I probably listen(ed) to a lot more live, natural acoustic, work than most audio enthusiasts - so perhaps I’m more sensitive to it.
Being a “preference” curve (or a set of curves, as there are different ones), lots of people like it. I’m just not one of them. Even though I do have a variety of EQ curves I use with some headphones and some music, some of the time (no one is getting “what the artist intended” at home, but that’s another discussion entirely).
The HE-1, for me, is really only interesting in the context of being “one headphone to beat them all”. To warrant dropping ~$60K on a single listening station, it’d have to fully replace the rest of my collection - or a very substantial portion of it.
Now, I would LOVE to have a single DAC/amp/headphone combination. And not just for logistical reasons. But so far, no one setup covers all the bases well enough to go there. The SR1a, in the right setup, and with EQ when needed, is the closest I’ve found so far.
But back to the HE-1 …
It’s one of the more listenable “Harman” curve adherents (“Harman Neutral” would be a reasonable description, even if it appears that the bass is lifted some). There are ways around that, EQ being the most obvious, that I could apply to dial that out if I wanted.
That’s not where my HE-1 issues end, however, nor is it the biggest.
Being an essentially all-genre listener, with a huge library, the HE-1 would be a fun addition to my collection. But it doesn’t exhibit the slam or impact I want with some genres, so the better dynamics and planars not to mention the ribbons beat it soundly there. It’s tonally a little wonky, so needs EQ there, and if I am EQ’ing I can do that with any headphone. I think it’s beaten in some areas (stage, ephemerality) by much less expensive systems, including the SR007MkII off a good KGSS amp. And overall I have tended to prefer the HE90/HEV90 (which I acquired relatively recently, but haven’t gotten to use much yet).
The DAC in the HE-1 isn’t up to the job for me. It feels edgy and unsettled, particularly in the mids and lower-treble. To get the best out of them, you need a high-quality external source. Which instantly breaks the “all in one solution” model.
And since, again, my interest in the HE-1 is really in the realm of getting rid of EVERYTHING else in my headphone world, it just isn’t quite there (HE-1 plus an M-Scaler/DAVE, Bartok, or three-box dCS stack is not “getting rid of everything else” …).