Frequency response: 5 Hz – 48,000 Hz
Sound pressure level (SPL): 123 dB (1 kHz, 1 Vrms)
Total harmonic distortion (THD): < 0.05% (1 kHz, 94 dB)
Cable length: 1.25 m
Connector: stereo jack plug, gold-plated, MMCX
Impedance: 16 Ω
Attenuation: -10 dB
Total Score
Introduction
I’m here with a review of the IE900, the last flagship of the ie series, which Sennheiser released in 2021 with the slogan “the purest, most natural sound”. IE900 dropped like a bomb on the high-end market with Sennheiser’s right and wrong choices. In this review, we will take a look at the IE900 from 2024 and discuss how it stands up to the competition today. The Sennheiser ie900 went on sale three years ago at $1500 and sold for $1300 for a long time. Today, the official price is $1199. I sourced the product myself. I’ve used the ie900 for a relatively short period of time before (when it first came out). In total, I spent more than 300 hours with the ie900.
Design & Build
Package
It comes with a big box and a full box of contents. This is exactly what comes out of the box:
- IE 900 in-ear headphones
- Balanced para-aramid reinforced cable with 2.5mm connector
- Unbalanced para-aramid reinforced cable with 3.5mm connector
- Balanced para-aramid reinforced cable with 4.4mm connector
- 3 pairs of silicone ear adapters (S, M, L)
- 3 pairs of foam ear adapters (S, M, L)
- Premium carry case with metal serial no. plate
- Cable clip, Cleaning tool & Cleaning cloth
- Presentation box with signed customer certificate & User manuals
I think it’s a Sennheiser classic to put 3 cables instead of a cable with interchangeable jacks. The tips are horrible. This is important, the isolation and fit is nothing but a disgrace with these tips. I couldn’t even put them on and listen to them, let review without them because the tips didn’t fit my ears. After a lot of experimentation, I got good results with the Pentacon Coreir tips and used them. I wrote this review based on my experience with these tips. Other than that, I had no problems at this stage. Everything else was as it should be.
CNC machined from monoblock metal, the shells impress in terms of workmanship and robustness. After finding the right tips, I had no fit or insulation problems. Some say the shells are too small (for the general ie series). What can they do, the driver is only 7mm :D.
Cable (Cables)
They look quite thin and frail, but I think they’re good. It feels like they’re going to break easily, but in fact they don’t. I know the IE900’s cable gets a lot of criticism, and to test this I also listened with the Effect Audio × Z Review 10th Anniversary Cadmus cable. Surprise! There were very tiny differences. To be honest, even if we accept the differences, I would have chosen the stock cable. As a result, I can say that the stock cables are successful.
Synergy
IE900 With iBasso DX180
The neutral-bright DX180 and the U-shaped and easily glowing ie900 are not the first pairing of choice. Yes, the mids are not bad in this pairing. But still the mids feel a bit recessive and create a feeling of emptiness. In the bass, the IE900’s great response saves the day. But the trebles are a bit of a grind. When we look at the technical part, the resolution seems enough, but the lack of control is noticeable. This means that nuances aren’t sharp enough and the texture of some instruments doesn’t reach the potential ie900 sound. The only thing to say about this combination is that it’s okay.
IE900 With Hiby FC6
When the FC6, stock cable and coreir leads are matched, sound is more balanced and be much improved. The result is an outstanding sound for a single dynamic driver. Resolution and detail reproduction of course could be better. But overall this pairing is great. The analog-like, slightly warm sound of the Hiby FC6 adds a velvety timbre to the ie900. The result is an untiring beauty in metal genres. There’s enough body and the mids don’t feel recessive.
Sound
Let’s get to your favorite part. In all sensory scenarios, the Sennheiser IE900 reminds us of two things very well. This is a high-end iem and this is a “western” iem. The first thing that strikes the ear is that it sounds more natural compared to high-end Chinese models. Before I go deeper, let me remind you that I did not use stock tips throughout this review.
Tonality
It has a well-tuned, balanced U-shape sound profile. The ends of the upper and lower ranges have maximum extension that can be taken naturally. In the midrange, it lacks excitement in places and is where it should be. I don’t think the midrange is timid, I think it’s a source-dependent feedback. Because the frequancy response is very natural.
Bass
Sub and midbass are in harmony and balance. The lower frequencies can go very deep and have a great texture. It seems to me that they slightly emphasized the lower frequencies in order to show us more of this quality (not for bassheads!). So well calibrated that it is not more punchy, but bigger. The bass expands and elongates in its place in the scene without overshadowing, distorting or diminishing anything. You can hear and feel the tension in the drums and the vibration in the bass guitar in the most realistic way.
Mid
The mids of the Ie900 are a bit recessive. The important thing is the place and meaning of this recessiveness. There is no imbalance, the sound is still natural. But the female vocals and sometimes the violins are a bit thin. When listening to multi-instrument tracks, you get a sense of emptiness in some sources. There is a lot to talk about mid frequencies in technical terms. You will read it in a few paragraphs. If we ignore them, we can say that the ie900 has a good timbre in the midrange. Not transparent enough, but realistic and consistent.
Treble
I take my hat off to Sennheiser for being able to extract such a treble from a single-dynamic configuration. The triple resonance chambers work well. If you look at it from a technical point of view, you realize that well-configured trebles have a positive effect on how the overall spectrum sounds. The fact that it can compete with iems with EST drivers is impressive. The trebles are bold and have good extension. It can be a bit too much at times. The truth is that there is a very fast rise here in the midrange. It can brighten up with ease. Despite this, it has a good timbre. Air frequencies and cymbal extensions are closer to what they should be compared to chifi high-ends.
Technique
Even though it came out 3 years ago, it was made with much more R&D than its far eastern competitors. The price has dropped about 300 dollars since its release. I’ll take all this into consideration. Resolution Great for the time it came out, but today it’s standard for $1000+ iems. When it comes to the stage, the ie900 is still a beast. It has good instrument separation for a single dynamic driver. Where it’s at its best is in layering. I find the positioning capabilities average and the imaging capabilities above average. They could have perceptually supported the technical achievement with tonality manipulations. But they preferred naturalness. This makes this headphone an optional choice.
The Sennhesier IE900 has very fast bass. It has an overall homogeneous resolution, but the lower frequencies are technically ahead of the market. The opposite is the case for the midrange. The upper frequencies are impressive for a single-dynamic driver because they are similar to other high-ends in terms of resolution, texture and microdetail reproduction.
The IE900 has a good frequency response and detailed presentation throughout the sound. It’s not far behind its competitors with multiple types of drivers. Texture, body, accuracy and consistency in the highs and lows are very good. In the mids, it’s obvious that it chooses its sources. With a nice match (analog-like and midcentric-warm sources are the best choices), you should have no problems, the feeling of emptiness and sparseness is minimized. But when paired with sources that are more on the analytical side, especially bright sources, you will get a lack of body in the mids and brilliance in the treble.
Sennheiser IE900 vs Yanyin Moonlight Ultra
…oh dude it’s gonna be like Conor vs Khabib…
They are both great iems. Yanyin Moonlight ultra is more balanced while the IE900 is more natural by a nose. The Moonlight Ultra has better energy and harmonization throughout the mid-upper range, while the IE900 stands out with its lower frequencies. IE900 more bright.
Yanyin Moonlight Ultra is more resolving and analytical. The Sennhesier IE900 has a better timbre, while the Moonlight Ultra shows more body and texture in the midrange. In the mid frequencies the ie900 has a better timbre, but the Moonlight ultra is better in this range with its full-bodied mids and realistic frequency response. While both have good detail, the Moonlight Ultra is better at microdetail reproduction and capturing nuances. The IE900 has faster and deeper bass, while the Moonlight Ultra has better note weighting. Still, given the amount of extension and extension, the ie900’s lower frequency response is better. Moreover, the IE900 has an excellent sub bass response. Throughout the lower treble, the Moonlight Ultra is more consistent, while the ie900 only has better separation here. Throughout the upper treble the Moonlight ultra is more technical and clearly stands out. Having the overall trebles so close together gives the ie900 an applause. Still, the Moonlight Ultra has more fresher and more detailed highs.
Technical Comparison
Yanyin Moonlight Ultra has a higher resolution. If we want to evaluate this quantitatively, the Moonlight Ultra is 100% while the IE900 is 90%. But this 10% difference means a lot to the trained ear. This difference is especially pronounced in the midrange. Instruments are more detailed and consistent in the midrange of the Moonlight Ultra.
Except for what I mentioned in the second paragraph of previous title, the Moonlight Ultra has better separation. When it comes to layering, the ie900 is better. Even though they are close in terms of soundstage, Moonlight Ultra is the winner again. Because it is wider. When it comes to positioning, they are close, but the Moonlight Ultra is slightly more consistent. When it comes to imaging, both are very good, they can be considered equal.
Moonlight Ultra is more transparent with more microdetails but also a bit more complex. When it comes to critical listening, the Moonlight Ultra is overwhelmingly superior. For everyday use, the ie900 may be the choice, and that makes sense. Because the IE900 is brighter but less tiring.
Last Words
The Sennheiser IE900 is still a great iem today. It’s a miracle of single dynamics. It’s a bit coy and doesn’t play well with every source. But when you get a good match it is quite enjoyable and spacious. If you put aside the mmcx incompatibility and buy aftermarket tips, you are one step closer to unlocking the potential of the ie900.
I think it can technically compete with today’s iems, I’m just not sure how long that will last (I’m writing this review in late 2024). Its natural tone and great low frequencies might make it a choice. At this point we should remember that this is a high-end iem. When choosing between high-end iems, we should think about which one suits us better and how well it will match the music we listen to and the sources at hand. Every iem in this price range already has almost perfect technique. The bottom line is that I still see the ie900 as an affordable iem. It’s great to get around 900-1000 dollars, slightly below the current selling price.
