Sennheiser - IE 900

Test Setup: Moondrop Dawn Pro (4.4mm balanced) + Sennheiser IE900

Pros ✅

Outstanding detail, clarity, and resolution 🎶

Excellent soundstage and imaging, feels very spacious

Bass is clean, tight, and textured (not boomy)

Scales really well with high-quality DAC/amp (noticed max performance with Dawn Pro 4.4mm)

Works best with FLAC/WAV or high-res files — reveals true potential

Stock memory foam and Final E tips give great seal and sound

Cons ❌

No ANC, so not suitable for travel or noisy environments ✈️

Very tip and fit dependent — comfort issues with long listening (tight seal causes ear fatigue in ~1 hour)

Stock silicone tips are weak in bass

Demands high-quality recordings — MP3s or poor mixes sound flat/harsh compared to even budget wireless earbuds

Price is high considering it’s only ideal in a quiet room setup

Verdict:
The IE900 is a true audiophile IEM — unbeatable in sound quality under the right conditions (quiet room + high-res files + good DAC like Dawn Pro 4.4mm). But it’s not practical for travel, casual use, or long comfort sessions.

Using these with the chord mojo 2. A delight to listen to music through these. Absolute powerhouse of an iem! These are the most comfortable iem's that I have ever used. No problem with wearing over long hours.

I am a great music lover who currently ventured into the world of IEMs. I am primarily don’t consider myself as an audiophile, the anticipation of experiencing Sennheiser's acclaimed sound signature through their latest offering, the IE 900 earphones, has been nothing short of exhilarating.

These in-ear monitors (IEMs) promise a premium listening experience, and this initial review captures my thoughts during the critical burn-in phase.

Right out of the box, the IE 900's exude luxury. The impeccable craftsmanship is evident in the solid yet lightweight anodized aluminum housing, designed meticulously with Sennheiser's proprietary X3R technology. The attention to detail reassures you of the durability and quality that Sennheiser is known for.

Moreover considering the fact that on first day, I broke both the mesh of ear buds which Sennheiser gracefully repaired within warranty without any cost. This has been discussed separately in my other post earlier in

https://www.theindianaudiophileforum.com/c/ask-the-community/i-have-mistakenly-damaged-ie900

The unboxing experience is complemented by a generous assortment of ear tips and a premium carrying case, reflecting the company's commitment to user satisfaction. This IE900 is designed in Germany and made in Ireland and I purchased from Amazon with effective price of Rs 89999 with a caveat 24 months no cost EMI. So effective cost is around Rs 77000 plus.

The initial fit is snug and comfortable, with excellent passive noise isolation that allows for an immersive listening session.

During the burn-in phase which is normally 30 hours or 5 hours per day for initial 6-7 days, which is crucial for any high-end IEM, the Sennheiser IE 900 is already hinting at its potential. Out of the gate, the sound profile is impressively balanced with a slight emphasis on clarity and detail retrieval. The treble is crisp and articulate, without any signs of sibilance or harshness that often plagues lesser IEMs during their early use.

The midrange, while still settling in, is already demonstrating a natural and transparent character. Vocals have a presence that's intimate, with nuances in performances being rendered with a lifelike quality that Sennheiser is celebrated for. It's clear that with more hours of play, the midrange will only become richer and more cohesive.

Bass response in the initial hours is tight and controlled but not fully upto its potential in initial hours. This will come into full potential post burn-in phase as I was given to understand. There's a satisfying level of punch and depth that doesn't bleed into the mids, preserving the overall balance. The IE 900 seems to be on track to offer a bass response that is both dynamic and detailed, catering to a wide range of genres.

Soundstage and imaging are other areas where the IE 900 is already showing promise. There's a sense of space and separation that's remarkable for in-ear monitors, with instruments and vocals placed accurately within an expansive soundscape. As the drivers continue to settle in, I anticipate these qualities will be further refined.

Connectivity has been seamless, with the provided cable offering both a secure connection and the promise of high-fidelity audio transmission. The option for cable replacement or upgrade is a welcome feature, ensuring longevity and personalization for the user. Thus I am waiting to buy 8 wires 4.4 mm balanced Effect Audio Cadmus wires when it is available in renowned stores like HPZ or Audio Store of Pune.

In conclusion, while the Sennheiser IE 900 is still in its burn-in phase, the initial listening experience is indicative of the earphones' high-end pedigree. The sound signature is evolving with each hour of use, and there's a palpable sense of anticipation for the acoustic excellence that will be fully realized post burn-in. If the initial impressions are anything to go by, the IE 900 is poised to set a new benchmark in the portable audio space and will be one the best audio gears in my presence considering I have experienced music from my AirPods Max, Sennheiser Momentum 4 and Focal Bathys. In BT TWS Devialet Gemini 2 is also an excellent collection of mine.

In the whole process Pritam of Audio Store is guiding each day to convert me from beginners club to serious pro grade audiophile.

PS. I paired up IE900 with my AK SR 35. I will post my detailed review once burn-in phase is over and paired up with 8 wires 4.4 mm balanced Effect Audio Cadmus wires.

This is the flagship model ... right side earpiece stoped functioning after 6-7 hours of usage... this is the fate of FLAGSHIP IEM IE900. vey much frustrated

A very good headset.

Sennheiser - IE 900

In the age of multi-driver technology IEM's, a single dynamic driver IEM & that too of a price it is at, is not only an anomly but will also be viewed with suspicion.
I too had my own doubt, but my search for a capable IEM was ongoing & wanted to purchase IEM that were sold with warranty (Products unavailable in India that cost lakhs, imported & that too without
warranty is too much of a risk to bear).
Product that I purchase without trail, like this, if for any reason I personally cannot find satisfaction then I sell it off. Solaris OG, Solaris 2020, Fiio FH 7, Fearless S8F, IE 800s, Mest MK II etc are some of the IEM's I previously owned & sold off either due to wearing discomfort or for how it sounded.
IE 900 after first few listens came across as lacking in impact, scale & cohesiveness. With Balanced Armateur(BA) sets, burn-in has not made much difference, but with IE 900's dynamic driver few days of burn-in truly changed the whole dynamics of sound produced by this IEM. I can assure that it was not me getting used to its sound, as I mentioned earlier with any audio product especially IEM or headphone if I don't find the sound produced endearing, then I just sell it off.
After burn-in the true character of IE 900 was revealed as having reasonably wide soundstage, extremely clean sound reproduction and a high level of musicality.
All this ends up being an IEM that is truly capable of delivering the true essence of any piece/genre of music.
Treble is well extended but never came across as harsh or sibiliant, never. Mids are extremely detailed & vocals sound extremely real. Bass has superb amount of energy & if a track has bass, be rest assured it will never shy away
from reproducing it with an impact. This IEM being extremely light & small, it has to be hands down one of the most comfortable IEM's you will ever come across. Even in sleeping position, this IEM never causes any problem.
Last but not the least, this IEM like may others depend on good eartips for it to sound great. Any eartip that dosen't seal well or dosen't allow IEM to rest properly can make it sound wonky & wrong.
Provided eartips do not do justice to this product. Many have rasied this point & I concur that provided silicone eartip is underwhelming. Foam eartips are better, but for excellent results I defentiley recommend Comply 500 series round eartips. I suggest buying large ones because irrespective of ear size, it fits easily & seals well. Usage for even long hours is convenient.
All in all, this is definetly a keeper, plus the provided balanced cabels & 2 years of warranty definetly deservers an appreciation.

You can't ask more of an IEM. Agreeable that its Ultra Premium but gives you every bit of return. Excels in all respects Comfort, Build, Sound. Haven't tried it with a DAC yet so the best is yet to come. Delivery was super fast - less than 24 hrs.

This is a review of both the IE 300 and the IE 900. I'll copy paste it in both sections.

Firstly, accessories (ear tips and cables) are a massive middle finger from Sennheiser to the buyer. The included silicon tips are absolute bottom barrel trash. They can not seal for me and while pulling one off the IEM it ripped the tip from the stem. The foam tips are useful and help me get a good seal, but I'm using them sparingly, because, like all foam tips they won't be too long lived. Replacement tips?

The cable is sticky, tangly, fights you at all times. The cables of the 900 feel a little softer and less sticky, and there are 3 of them, but still these are far form decent for the price. Sourcing a good replacement cable will be a problem because of the non standard termination. I have bought a replacement cable "Tiandirenhe cable for IE 300, 600 and 900". It feels flimsy and cheap, and I'm not hopeful as to it's longevity, but that cable in feel is a humongous upgrade. I fail to see how a leader in the audio industry is so clueless. I was reading a discussion on a forum where Sennheiser reps., on being asked if they could recommend a replacement cable asked a person what the problem with the stock cable was.

Both the IE 300 and IE 900 are comfortable and after trying different ear tips I've found the best ones for me are the included foamies and Spinfit CP100 plus. It's unfortunate Hpz doesn't sell the CP100 plus. Also sourcing the original foam tips might be a problem. The seal is fidgety and while I can maybe attribute that to my ear shape being wrong, these aren't my first IEMs.

Sound is simple. both of these are basically detailed, pleasant with a good amount of bass. Having said that The IE 900 is FAR better than the IE 300s. More resolution, better imaging/ staging and bass. So much so that IMHO the IE 300 are bad value at their price and the IE 900s, while not good value get a pass because the summit fi section has insane pricing anyways.
In fact I thought my IE 900s were broken and were imaging off centre because of the extreme positioning capability. I sent them in for warranty and they returned them saying its fine. I was still not convinced and as a final resource played tracks on mono. the image was dead centre. Basically when you have multiple vocalists close to centre, the IE 900 can locate them precisely.

This review sounds ranty, and that's unfortunate. The headphones are good but are let down by the absolutely trash accessories. They could learn a thing or two from brands like Fiio. At least the carrying boxes are pretty.

Bottom line. IE 300s, OK, but 10k chi-fi is competitive. IE 900s, GOOD. They know it and have priced them accordingly.