Sennheiser IE 900 Review

Sennheiser IE 900 Award

Sound Classics – Short



Dynamic bass. Powerful, detailed and perfectly controlled. The IE 900’s bass can go really deep when needed and there’s even good sub bass rumble. As said before the bass has good body in a high end more neutral kind of way.

Bass detail is good, and the layering is excellent. Bass is never exaggerated but has a good punch and kick in the delivery. Bassheads should look elsewhere, in this high end monitor it’s all about quality, not quantity, but at the same time I never felt it lacking. Do note that a really good fit is needed to get the best possible bass. To me it’s not always easy with the IE 900 and its tip selection, and I really have to precisely put the units in my ear to get the perfect seal to get the optimal bass experience.


The mids nicely connect to the bass and what you’ll notice here first is the upper mid focus and the more forward vocals. At the same time the mids do have good layering and depth, and this comes with a spacious, airy presentation.

Detail-wise the mids are good and if you like vocally strong music, you’ll be impressed. I personally also really like how the IE 900 renders guitars. Mid-depth and layering here also is excellent.

Sennheiser IE 900


The IE 900’s treble section is energetic, engaging and very lively. Treble has great extension and excellent detail retrieval. The decay in the treble section is really impressive. We all know the Sennheiser high end treble and they’ve made sure you’ll recognize the house style in the IE 900.

Single ended

The first difference with balanced is that you in single ended configuration get a more intimate presentation, with less space between the notes and an overall less airy presentation. You do get he sense of the IE 900 sounding fuller. The second main impact is on the bass, which in single ended mode isn’t as precise and extended, but it do is fuller and it comes in with more punch and impact.

The third difference is in the top end extension and energy, which now is not as pronounced. And finally the vocals blend in more where they in balanced mode are more upfront. All-in-all you in SE mode get a full sounding, still balanced IE 900. In SE mode it’s a bit more about quantity and presence than it is about transparency and precision, but it’s still very good on all levels.


The tip selection as usual is critical. You really need a perfectly sealing fit to get the IE 900’s body and bass presence as it’s supposed to. With the IE 900 that for me means I have to use the biggest size memory foam tips that come with the IE900. Normally use a smaller size tips, but as the nozzle is quite small, I need to use the largest size with this IEM.

Sennheiser IE 900

I have also tried the foam tips that come supplied with the 64 Audio U18s but I didn’t find them to deliver the same quality sound as the Sennheiser ones. Especially in regards to the body and bass, as they made the IE 900 sound lighter.

The silicone tips that come with the IE 900 just don’t work for me. I can’t get them to properly fit my canals, not even the largest size one, and as a result you get thin, light and body-less sound, with very little bass. It’s just not good for me, it doesn’t sound right. Of course the silicone tips might be working for you.


Does the Sennheiser IE 900 benefit from or change with a different source? That’s what we want to learn here. With its 180hm impedance and 123dB sensitivity, the IE 900 on paper is extremely easy to drive. In reality, that’s also completely true, you don’t need a special amp to make the IE 900 sound good, but you can use a different source to tune the IE 900’s sound hardware-wise.

With the Centrance HiFi-M8 V2 in balanced mode, the IE 900 sounds musical, precise and fuller. The technical performance is not the highest but it’s still good. Most of all it is pleasant and easy to listen to, with a very musical sound. It’s a really engaging source/combo and one that I with the Cleopatra cable absolutely love listening to.

With the Astell&Kern SP2000 in balanced mode, the IE 900 sounds more refined and precise and it has better extension. It’s lighter looking at the amount of body from bottom to top and it’s more analytical sounding. Body-wise it is lighter but the IE 900 and SP2000 combo is linear, precise and very detailed. Compared to the Centrance you lose some musicality, but you gain on what the SP2000 is perfect for: technicalities. If that’s your thing than this is a really nice combo to listen to.

Sennheiser IE 900

The Chord Electronics Mojo is a unit I haven’t listened to for over a year, since I started homeworking. I have two Mojo’s and I use one of it as my main DAC/AMP in my office in the capital, but when we went in lockdown, it stayed in the office. I had a good feeling the combo would sound nice and it indeed does. You get a great mix of technicalities, speed and energy but you also get a good amount of body and a very high musicality factor. The combo is single ended only but it is very engaging. It’s not as full sounding as the IE 900 and Centrance combo, but it’s so much stronger when it comes to sound quality. Good extension, lovely decay, just the right amount of energy, etc. A lovely match and one I for sure will be using more myself.

The HiBy R8 DAP in balanced mode is one of my favorite players for late-night listening. It’s somewhat fuller and darker sounding but it’s musical and dynamic at the same time. The IE 900 with the R8 sounds bigger like with the Centrance, but it’s more spacious and airy sounding, with better extension and decay. You get the same musicality, energy and engagement but it’s a technically stronger source. DAP-wise it’s one of my favorite sources with the IE 900.

Last up for this test is my OnePlus 8Pro smartphone (using a USB-C to 3.5mm SE dongle). If bass is your thing, especially in quantity, then your smartphone might be a good source for the IE 900. You lose some extension, precision and dynamics, but you in return get a really full sounding IE 900, with bigger bass and a warmer smooth presentation. For me it’s fun for a while, but it’s a bit too much for longer listening session. It’s very cool to see what the single driver can do for bass though.

Sennheiser IE 900

Conclusion: Power and volume wise none of the sources have an issue with the IE 900, but they don’t all have the same end result. That can be good or bad depending how you look at it. I like it as I have many sources to my disposal, but if you have only one, be careful with what you’ll drive the IE 900 with and make sure you get your preferred type of tuning.

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

Page 1: Sennheiser, Intro, IE900, Specifications, Box & Accessories

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

Page 4: Cables, Competition, Conclusion, Award


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.

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