IE 900

You should definitely check out the Sennheiser IE line. From their cheapest IE200 , their midrange IE600 and to the most expansive IE900 they are all amazing iems, with incredibly small shells. Small enough to actually sleep with, as they do not stick outside of the ear.

Sennheiser IE900s + JDS Labs ATOM stack (DAC/AMP).

Exactly the same experience like yours. I started with IE600 and like it a lot. Jumped to IE900 later because of a deal too good to miss. It is truly an endgame IEM. The bass texture and clarity is way above IE600, I also appreciate the extended treble. I described it as analytical bass head IEM. The FR cannot justify it, it is a shame that so many people simply bash it based on graph alone. The bass texture, clarity, and sound cohesion cannot be read via graph. You have too listen to it. It stands pretty well against my HD800s and E3 for analytical listening, and go toe to toe against MDR z1r for fun stuff. It is such a good value to me. My 2022 Focal Utopia is on its way, we will see how much I still love it after Utopia.

I owned IER Z1R before. I wouldn't say IE900 is better than Z1R. Z1R's bass has better texture although it doesn't go as deep as IE900. I believe he bass impact of Z1R is due to the magnesium dome used in its 10mm DD, it actually kind reminds me the Focal impact. Z1R's upper mids and treble are hotter. I sold it because of the fit is too painful for longer session.

Ie900, analytical bass head IEM with great fit and isolation. Can play most genres well.

For me, the IE 900 is firmly in endgame territory. I’ve tried a lot of IEMs, but my top three would have to be the IE 900, Z1R, and KSE1200—each has its strengths, but the IE 900 is my daily driver. It’s incredibly comfortable and, in my opinion, its sound quality rivals some of Sennheiser’s open-back headphones. My setup is similar to yours: IE 900 paired with the Chord Mojo 2 and Poly, using a Moon Audio Silver Dragon cable. I take this setup with me to work every day, and it never disappoints. https://preview.redd.it/mwjltc1nsl2f1.jpeg?width=4032&format=pjpg&auto=webp&s=e1e59ac3a68727abbd6b7bbff7a53c7daa10206d

I think it depends how you buy your IEMs right? When I'm looking for something new I'm looking for something that actually has physical hardware differences. My first pair was just a good all rounder, a nice baseline and a huge upgrade from anything else I had at the time. My second pair had bone conduction drivers which immensely improves the low end. While testing that bone conduction set I also got to try out some of the 64 audios with Apex porting. They're so comfortable to listen to. They're significantly more expensive but I would still consider them noticeably better. On the flip side I also got to try the Sennheiser IE900s at the same time and I think they're absolutely garbage for the price. It's mostly gonna be down to personal preference but if you keep buying IEMs that are essentially the same thing repackaged a new way, sets that aren't doing anything drastically new or different, the fall off is probably going to be closer to $300-400.

By that logic ie600 , tanchjim origin , ie900, mk12 , ea1000 and many others is not worth it.

Your impressions are totally valid. Psychoacoustically, the IE900 *can* feel like it has a wider soundstage than the HD660S2 — I’ve owned and listened to the 660S2 for a while as well. That spaciousness comes from Sennheiser intentionally sacrificing some presence in the mids, which creates the perception of more openness. But as a trade-off, you lose the kind of midrange richness you get with the 660S2. Of course, no IEM can really match a good open-back headphone when it comes to mids. I still remember how moved I was listening to Bon Jovi’s *It’s My Life* on the 660S2 — that texture and emotional weight in the vocals just hit differently. The IE900 can’t quite reach that. But for a lot of music, I do prefer what the IE900 brings to the table in other ways. I guess it all comes down to the trade-offs made in tuning and design.