Sennheiser IE 900 Review

Sennheiser IE 900 Award

The Sennheiser IE 900 is Senn’s newest reference earphone, selling for €1.299 Euro.


Disclaimer: The Sennheiser IE 900 IEM was sent to us by Sennheiser directly, in exchange for our honest review. Sennheiser is not related to Headfonia in any way. 


Everyone who is into headphones surely has heard of the German Sennheiser. Sennheiser has been active for 75 years and they recently celebrated that with a special Anniversary Edition of their modern classic headphone, the HD 800 S. Check it out here.

Sennheiser is one of the most respected companies in audio and in the past years, Sennheiser has positively surprised us with a lot of top quality products such as the HD 800 (S), the HD 820, the HD 660 S, the HD 560 S and several other HD 5-series headphones. Sennheiser has also been active on the IEM and TWS market and the IE 300, Momentum True Wireless 2 scores pretty well there.

We’ve of course featured and reviewed many Sennheiser products here on HFN. My personal favorite Sennheiser headphones are the HD 800 S, the HD 650 (on tubes) and the HD 660S.

In today’s review we’ll be taking a close look at the IE 900 IEM: Sennheiser’s newest single driver, top of the line earphone. Or how Sennheiser says: “a new benchmark for portable audio fidelity”.

Sennheiser IE 900


Just last week, Sennheiser announced that the Suisse Sonova would be taking over the consumer part of their business. That was quite the news and we shared it last Friday. Now if you have read that article you will have also noticed that Sennheiser allowed us to announce a new unit that would be released on May 11th, today.

The article title has already given it away, but we can now freely announce that the unit we teased you with in fact is the Sennheiser IE 900 IEM. Senn’s new top of the range monitor. Interesting note; none of the readers on our site and social media guessed that. In fact the most guesses were about a new TOTL headphone above the HD 800 (S) and a successor of the HD650. But no, it’s a high end IEM called the IE 900, and  it’s available starting today.

Let’s start to discover!

IE 900

Here’s what Sennheiser has to say about the brand new high end closed type IEM:

“With the new IE 900 audiophile earphones, Sennheiser has brought together technical innovation, meticulous attention to detail, and an uncompromising demand for perfection to deliver a listening experience without compromise”.

The new IE 900 boasts Sennheiser’s proprietary X3R transducer, a refined version of the audio specialist’s 7mm audiophile Extra Wide Band transducer featuring a unique triple-chamber absorber system. They are milled from a single block of aluminum to create its unique triple-chamber absorber (T3CA) system. Originally developed for the IE 800, the IE 900 features the next generation of the patented absorber system, which uses three chambers and an acoustic vortex milled into the nozzle to counter the masking effect.

According to Sennheiser, “this acoustic phenomenon arises as the human ear cannot perceive high frequency sounds at a low volume if louder sounds in a lower frequency range occur at the same time. By removing the energy from masking resonances, the absorber system prevents undesired peaks, making even the subtlest nuances of sound audible”.

Sennheiser IE 900

For now you can find out all about the IE 900 in this review, as the dedicated web page is not active yet at the time of publishing. Once online I will add the link to the product page right here. I’m guessing it will be something like

The Sennheiser IE 900 is selling for €1299 Euro, putting it in the high end part of the personal audio market.

Technical Specifications

The driver inside is an evolution of the Sennheiser 7mm XWB driver, the X3R. I know some of you were hoping for a completely new driver, but it in this case it’s an evolution. The Sennheiser IE 900 IEM features a newly developed membrane foil, providing a high degree of inner dampening, ensuring minimized natural resonances and distortion.

Jermo Köhnke, is the Product Manager at Sennheiser in charge of the IE 900. Let us know if you’re interested in us doing a live stream with him, so he can answer all your questions.

Full specs:

Transducer principle:      Dynamic, Extra Wide Band (XWB)

Transducer Size:               7mm

FR:                                          5 to 48000Hz

FR Characteristic:             Diffuse-Field Equalized

Ear Coupling:                     In-Ear, closed

Impedance:                        18Ohm

SPL:                                        123dB at 1kHz, 1 Vrms

THD:                                      < 0.05% (1kHz, 94dB)

Attenuation:                      -26dB

Cable:                                   Oxygen-free Copper Cable (OFC), para-aramid reinforced, ear hooks: TPU Coated

Connectors:                       Gold-plated, Fidelity Plus MMCX. 3.5mm unbalanced 3-pin, 2.5mm balanced 4-pin, 4.4mm balanced 5-pin

Weight:                                +-4g/earphone (without cable)

Sennheiser IE 900

Box & Accessories

The earphones come in a very nice multi-layer box, as you can see in the pictures. With a high end unit at this price, we expect the very best and Sennheiser has surely delivered in this regard.

When you slide open the inner box, you will immediately see the 2 ear pieces on top, embedded in foam. On the next level you will find the certificate of authenticity, with your Serial N°, quality check stamp (April 7 for mine) and the signature of the Quality Controller. A very nice touch we often see with higher end gear.

On the third level you will find the main compartment with all the goodies:

  • 3 pairs of foam and silicone tips (S/M/L),
  • a cleaning tool,
  • a shirt clip,
  • a carrying case,
  • 3 sets of cables

On the last level, you will find a cleaning cloth and a multi-language manual.

All-in all a very complete package and everything you expect when buying high end earphones. Knowing Sennheiser, I didn’t expect anything less, and it’s all in the little details. An example is the personalized carrying case for each set of IEMs, with the serial number labeled on a metal plate. What’s not to love?

The article continues on Page Two. Click here or use the jumps below.

Page 2: Design & Housing, Build Quality & Cable, Fit & Comfort & Isolation, Sound Part 1

Page 3: Sound Part 2, Single Ended, Tips, Sources

Page 4: Cables, Competition, Conclusion, Award

4.1/5 - (200 votes)

Lieven is living in Europe and he's the leader of the gang. He's running Headfonia as a side project next to his full time day job in Digital Marketing & Consultancy. He's a big fan of tube amps and custom inear monitors and has published hundreds of product reviews over the years.


  • Reply May 11, 2021


    Can you compare it to the IE800(s)?

  • Reply May 11, 2021


    About Xelento, I had it but finally sold it because I’m more an headphone guy : the foam tips is not the better match with Xelento, in fact the olive tips (with the bigger size) provided with Xelento is what really reveal the Xelento, with these tips the sound coming from Xelento is impressively out of your head, it is really headphone like and an experience to try.

    You can easily find Xelento less than 1000eur (amazon, etc)

  • Reply May 11, 2021

    Daniel afred

    pls can you tell me the differences between the IE900 and the Audeze euclid

  • Reply May 11, 2021

    Daniel alfred

    Good review by the way

  • Reply May 11, 2021


    Thanks for the great review. I’m very interest to read how Senn IE900 compares against Final Audio A8000.

    • Reply May 12, 2021


      How does the ie900 compair to the JH Roxanne?

  • Reply May 12, 2021


    Well done senheizer

  • Reply May 14, 2021

    Paulo Lobao


    Compared to CA Dorado2020…?

  • Reply May 21, 2021

    da berg

    It is a shame in todays age where people want wired headphones of high quality for their phones this did not leave an option to purchase with a mic.

    If it had a mic I would totally buy it

    • Reply August 1, 2021


      You buy a high quality wired headphone to play with DAP! Not a phone. lol

  • Reply May 23, 2021

    Paradorn Suksingha

    Please pairing with Shanling M8 and share experience. Thanks.

    • Reply May 23, 2021


      I don’t have the Shanling DAP here, sorry

  • Reply July 28, 2021


    The most obvious difference is the extension of the high frequency part. The high frequency of ie900 is bright and natural. In other aspects, ie900 has a very good sense of hierarchy and better analytical power. It sounds like ie800s has 2K image quality and ie900 has 4K image quality

  • Reply September 5, 2021


    Can you share how they sound with fiio m15?

    • Reply September 7, 2021


      I don’t have the M15 with me, sorry.

  • Reply February 2, 2022


    When you say easy to drive, is that equal to sensitive?
    For example do you ever push the volume over 25 on balanced connection with sp2000?

    • Reply February 4, 2022


      driveability is always linked to sensitivity. I don’t remember the exact volume position for the IE 900 in balanced mode, however.

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