The Sennheiser IE 900 is one of the most expensive wired earphones I have reviewed. Retailing in Singapore at S$1999, Sennheiser has further refined their signature sound to be even more pleasing to listen to. While many of the pricier earphones in the market boast elaborate premium materials or multi-driver components, the IE 900 exhibits pure engineering feat, true to the German spirit.

As I always mention, I generally do not indulge in the marketing messages that are crafted to promote the products. What matters is the real result. The IE 900 aluminum housing is precision-milled and anodized with a five-axis CNC machine to achieve precision cuts with a single block. The XWB 7mm TrueResponse transducer driver is improved, and the all-new X3R technology, which comprises of a triple-chamber resonator absorber system, is the heart of the audio magic that you will hear on the IE 900. Apparently, the tiny channels eliminate resonance peaks which, in less advanced products, can color the sound signature and alter the feel of your music. A complex structure in the nozzle of each earphone – the vortex – swirls acoustic energy in these frequency bands to smooth out peaks. Then there is also the acoustic back-volume – a chamber within a chamber – to control the direction and overall volume of air as it moves through the transducer system.

The retail package comes with three cables – 3.5mm unbalanced, 2.5mm balanced, and 4.4mm balanced. The cables are the same as the IE 300 which creates cable rub noise (microphonics), a rather annoying phenomenon when you use it on the move. It also comes with 3 pairs of silicone ear adapters (tips) and 3 pairs of foam ear adapters. The serial number is engraved on the carrying case, and also included is a cleaning tool, cloth, and cable clip. There is a certificate of authenticity with hand-written serial number and signature of the QC operator from Germany. Each unit is paired to achieve perfect channel balance with 0.5 dB deviation.
With so much audio engineering invested into the earphones, how good does the IE 900 sound? I don’t want to go into all the audiophile jargon here, but the IE 900 is clearly – pun intended – outstanding. Anyone who loves the sound of crystal-clear audio reproduction will instantly be attracted to the sound signature. Now, it’s not just the ability to make the earphones sound transparent or sparkly, but to be able to deliver the sizzle without the harshness and fatigue.

If this description seems to also apply to IE 300, that’s where the IE 900 is further refined. Honestly, when I reviewed IE 300, I thought they sounded good enough. Then when I listened to the IE 900, I realised how better they sounded. The IE 300 treble is a tad thin: they sound clear, but lacks the body and warmth. Here, the IE 900 improves on that, giving more soul and fullness to the vocals and the percussion while easing on the sibilance. At the lower frequency, the IE 900 is slightly tamed compared to the IE 300, sounding less “consumer”-like. This allows the mid bass and midrange to sound a little cleaner, more musical.
Is it worth four times the price? I think this is what distinguishes audiophiles from consumers. The IE 900 is a better tuned earphones, though like the IE 300, it is not exactly “faithful”. What it actually does is to make your listening collection more detailed, “remastered”. I can hear a lot more finer details at the top end, like the breathing sounds and acoustic instrument noises which add to the ambience of the recording. This also means that source files with poor compression will sound rough and flawed.
How does it compare to the HD 800 S? Between the two, I find the IE 900 is a lot easier to enjoy and like, because it delivers punchier tighter bass and extracts more treble clarity. However, the HD 800 S is more musical, the midrange is more forward, vocals are more real, not as artificially sanitised. For listening enjoyment, I would pick the IE 900. It is also less picky on the source player, so you can extract excellent sound presentation on any portable device, as long as the audio compression is close to lossless. With the HD 800 S, you need a good source to elevate the sound quality.
- Bass – 8.5/10. Punchy tight bass without too overpowering.
- Midrange – 7.5/10. Clean upper midrange that remains full and detailed.
- Treble – 9.2/10. Outstanding treble that sparkles with extension.

Verdict
For the longest time, a treble with boosted brightness is associated with brittle, harsh and fatiguing sound. That problem appears to be resolved with IE 900. If you like your music to sound very transparent and sparkling without the harshness and sibilance, you will find the IE 900 will achieve the results with ease. It is a heavy price to pay, but that kind of sound tuning is one that EQ cannot fix. Go to your favourite audio gear shop and try out yourself, but please be mentally prepared to part your cash once you audition it. Alternatively, ask to try out the IE 300 at the same time, and maybe your ears could accept the cheaper model.





