The frequency dips exhibited across the hifiman range are located in two specific frequency bands, and those bands and several others are often the distinguishing factor between a professional or reference quality headphone, and one meant to maximize consumer enjoyment of poorly recorded music from the last or indie groups of the present.

Hifiman range house FR tendencies are not there to be neutral or fully exposing of everything there. They are made to make harsh recordings sound less harsh in the two frequency bands which a large segment of the population find irritating.

Problem is, when you listen to extremely well engineered well mixed great recordings, the vocals and upper midrange detail as well as percussion sparkle are very recessed in every hifiman headphone, it’s a conscious tuning choice the company has made to please a significant portion of sensitive lay consumers.

So for those who find many treble - rich headphones fatigueing or irritating, hifiman can be a good choice. But for those who want something more neutral and more honest, more revealing of every detail present, or those who need such detail to work properly, they are not the best choice.

I would also add that the XS soundstage is not superior at all to the AKG K6/7/8 series. The soundstage width does come very close though. But because of the tuning, they simply cannot match the upper mid fine detail and high end sparkle and overall FR honesty in the similar width space the XS can provide.

AKG’s k6/7/8 lines can do more detail and more sparkle and more revealing, accurate placement, in a giant Nearly 360’ space, as opposed to just a laterally wide space