S$1,999 or US$1,300, the price tag alone is shocking. It’s almost the same price as my custom IEMs, and it’s actually more than a lot of more affordable custom IEMs as well. So is it worth the price?

 

Let’s talk design, both inside and out. Sennheiser has CNC-milled these out of a single block of aluminium and anodized them to create these gorgeous-looking earphones.

You get these beautiful grooves that really add some texture and character to the shells, and I really like it. There’s a flat faceplate area that has the Sennheiser logo printed on as well as the IE900 model name printed on the left earphone.

Under the faceplate, you’ll notice an air vent on either side, which makes sense because Sennheiser is still using a dynamic driver, that traditional 7mm driver. Here, you might be thinking, US$1,300 for a single driver universal IEM, that’s insane. Yeah, I thought the same at first too. But here’s how you should look at it: because it’s a single driver, there’s no crossovers needed, so you actually don’t get that distortion. It’s a very coherent sound, and you don’t get the phase issues and stuff like that. Plus, the comfort is incredible because it’s so small and light. There’s basically no wearing fatigue, and I can wear these for hours on end.

More than that, though, Sennheiser has introduced a new X3R technology, which combines the driver with three Helmholtz resonator chambers milled directly into the shell, designed to eliminate resonance peaks in the treble range, as well as an acoustic back volume that sits behind the driver that’s supposed to affect the low-end frequencies. More on the sound later, though.

You still get the Fidelity+ MMCX, so if you’re looking for third-party cables, make sure they fit the bill. Otherwise, you won’t be able to plug them into the recessed sockets.

Sennheiser has included a 3.5mm single ended, 2.5mm balanced as well as 4.4mm balanced cable in the box, which is excellent. For my testing, I mostly used the 2.5mm balanced cable. These cables are actually the same para-aramid reinforced ones that you get with the IE300, which means the cable is still a bit sticky and could cause a bit of microphonics as well as give you a tough time trying to untangle them, if you ever get them tangled up. Generally, though, they stay looped up pretty well, so if you put them in the case that Sennheiser provides, it shouldn’t be an issue at all.

The hard-sided case provided by Sennheiser is actually pretty nice. On the case, you even get a metal plate that has the name of the earphones as well as the serial number engraved on them. Sennheiser also provides some foam tips in the box, which helps with noise isolation, as well as a cleaning tool.

Honestly, this is where the price starts to feel a little better. You get a sturdy case, cable options, and the serial number and certificate of authenticity is a nice touch. I mean Sennheiser does a pretty good job at making these feel premium enough to reduce that post-purchase dissonance.

 

On first listen, it becomes incredibly clear that the IE900 is actually very well balanced. The bass response is great. You get a clean sound that can go deep when needed but still retains plenty of speed, detail and texture. There’s also very decent sub-bass extension, and overall, it’s very well done. The mids are lush and very natural, especially when it comes to vocals. You get plenty of expressiveness and it’s just a beautiful sound. And of course, detail, detail, detail. This IEM is excellent at pulling out all the details and presenting them really clearly.

Moving on to the treble, I’m actually happiest about it. I love energy and sparkle in the highs, and the IE900 provides all of that without ever crossing into sibilance for me. People who are more sensitive to treble might find it a bit too bright from time to time depending on the music, but personally, I never had an issue with it. The fact that this kind of treble response is coming out of a single dynamic driver is mind-blowing. I would expect it out of a multi-driver IEM with dedicated balanced armature drivers, not from a single dynamic driver.

Also, instrument imaging is absolutely incredible. The soundstage is wide, not as wide as some IEMs can get, but the accuracy and imaging is just wow. Layering and separation is great as well with enough space between instruments and a surprisingly clear separation of the vocals.