The AD1000x reminds me a lot of the good old Hifiman RE-0. I really miss those. Unfortunately, mines dropped onto concrete and broke as I walked out of a Dunn Bros coffee house carrying a cup of coffee in one hand and clumsily trying to place the IEMs into my ears. That was 4 years ago. To this day, I believe those IEMs had the absolutely best treble out of all the ones I've tried, including Ety ER4S, which has been very much overrated imo. The RE-0 was also quite mids-forward, and did quite well with female vocals. Its bass had similar quality to the AD1000x also. Hifiman seems to have produced some really great products...I don't know why they kept discontinuing them. Their current RE-x00 line is sub-par compared to their earlier works, imo. If I have to guess, they're probably trying to appeal to the western market, where people favor a less mids-focused, and more warm signature.