I thought it noteworthy pointing out an in-ear monitor (IEM) headphone review that posted on Audio Science Review.

https://www.audiosciencereview.com/...uthear-x-crinacle-zero-iem-review.37380/

This IEM closely hugs the Harman curve, and it's $50 USD. (!) There's a lengthy forum discussion discussing the merits of the Harman curve (science), conflicts of interests of the Crinacle review site promoting an OEM design, and the ick factor of IEM's (personal preference).

There is a momentum of manufacturers using the Harman curve as a target curve.

https://acousticstoday.org/he-perce...y-what-do-listeners-prefer-sean-e-olive/

We already know that the Axiom 3-way speakers nail the NRC recommendations, from which the Harman curve is based.

https://www.axiomaudio.com/boards/u...ating-on-axiom-s-olive-scores#Post444691

https://www.axiomaudio.com/boards/ubbthreads.php/topics/445486/two-curves-is-enough#Post445486

I personally don't have a need for a set of headphones that lack microphones nor active noise cancellation, but it's interesting that audio science is reaching mass market price points.

Author of "Status 101: How To Keep Up In A World That Keeps Score While Buying Into Buying Less"