IE 900 - The precision-manufactured aluminum housing of the IE 900 faithfully protects the dynamic TrueResponse transducers at the heart of Sennheiser’s innovative X3R technology. Experience the peak of German audio engineering and manufacturing with earphones that deliver only the purest, most natural sound.

New benchmark in portable audio
Ultimate precision & craftsmanship
Made in Germany
X3R technology: TrueResponse transducer combined with three Helmholtz resonator chambers and acoustic vortex
Precision-milled and anodized aluminum housing
Hand-assembled at Sennheiser´s headquarters

Gold-plated Fidelity (+) MMCX connectors for improved stability
Choice of para-aramid reinforced cables (2.5 mm, 3.5 mm, 4.4 mm)
Adjustable ear hooks and choice of ear adapters including memory foam
Frequency response: 5 Hz - 48,000 Hz
THD: 0.05% (1 kHz, 94 dB)
Impedance: 16 ohms

The IE 900 — goodbye to tradeoffs

High-fidelity recordings are pieces of art. Just as with a valuable painting, it would be a disgrace to allow damage during transport. The IE 900 reveals the true potential of any recording. If it’s a masterpiece, you’ll hear it. Brilliant, sparkling treble — with no trace of sibilance. Powerful lows without creating muddy mids. An uncanny ability to resolve fine detail — alongside warmth and comfort for extended sessions.
All these qualities derive from inspired feats of engineering. Take Sennheiser’s trusted 7 mm transducer, for instance. We’ve made it just that much better for the IE 900. Or the all-new X3R triple-chamber absorber technology milled right into the solid aluminum core with its downstream acoustic vortex. Taken together, these innovations deliver a unique level of balance and transparency — so you never have to compromise again.

Explore every last detail

Considerable effort goes into capturing the finest nuances of a musical performance. Re-living the creativity and texture recorded in the studio or concert hall can be a source of great pleasure. But only if the listener’s playback equipment allows. Our German-engineered and manufactured TrueResponse driver ensures exceptionally natural reproduction. A large part of its very precise transient response comes from the unique combination of materials in the diaphragm together with its high inner dampening. So when the signal stops, the sound stops too. This is how the IE 900 can reveal details in tracks you thought you knew inside out.
But the only thing that counts is what you, the listener, hear. The tonality of each instrument becomes clearly audible. And it’s not just the skills of the musicians that the IE 900 reveals. Even the acoustic properties of the room gain a new presence. Instead of remaining on the surface, you can now dive deep into complex passages — all while immersed in a breathtaking sound stage.

A new level of clarity

In developing the IE 900, we faced a fundamental choice. The inherent compromises multi-driver systems require (phase issues and the resulting distortion in overlapping frequency bands) made the decision easy. There would be a single dynamic driver only — of the highest quality, of course.
To get exactly the sound we were looking for, we designed a sophisticated system of three Helmholtz resonators — the X3R. It’s milled right into the solid aluminum housing of each earphone. These tiny channels eliminate resonance peaks which, in less advanced products, can color the sound signature and alter the feel of your music. In addition, a complex structure in the nozzle of each earphone — the Vortex — swirls acoustic energy in these frequency bands to smooth out peaks.

An acoustic back-volume establishes balance

Our goal was to achieve a transparent sound with no distracting peaks or troughs. One thing this requires is clear separation of lows and mids. To ensure accuracy across this critical frequency band, we’ve employed what is known as an acoustic back volume. It’s a small chamber within a chamber we have tuned to manage the slope and amplitude of the base lift. The way the back volume helps achieve such a clear and natural sound signature is by controlling the direction and overall volume of air as it moves through the transducer system. What you hear is a pleasantly disciplined bass and mid-range experience. Unpleasant resonances and listening fatigue vanish in this small space with a big effect.

The sound of manufacturing expertise

We build the IE 900 exclusively at our famed German manufacturing facility. It’s the source of the outstanding quality Sennheiser products are known for the world over. Aluminum was the material of choice for this application. Well-suited to high-precision milling, it also provides an aesthetically pleasing, long-lasting home for electro-acoustic components. A five-axis CNC machine precision cuts each housing individually from a single block of aluminum. The result is truly a work of art. Once anodized, the housing is highly resistant to wear and corrosion — music to the ears of any daily listener. The drivers in each pair of IE 900s are matched during our automated manufacturing process to practically eliminate variance. The result? A transparent soundstage with no gaps or holes.

A precise fit for precise sound

Working musicians rely on high-quality, form fitting earphones known as personal monitoring systems. But we felt the privilege of enjoying perfect live sound should not be the exclusive right of the performers of the world. So, we took the comfort and secure fit of these professional solutions as inspiration for the IE 900. Now you can enjoy a fit and quality that rival that experienced by the artists who create your music. Included with the IE 900 are silicone ear adapters and three elastic foam ear adapter sets in three different sizes. They adapt to the natural shape of your ear for a tailored fit. We’ve all been there: an amazing piece of music spoiled by a recurring bass note that happens to match the resonant frequency of your loudspeakers or headphones. Or rough treble sibilance that makes longer sessions uncomfortable. Such obvious deficiencies are unthinkable with the IE 900. All you will hear is precisely what the artist intended. They’re perfect at your desk, on a train, or taking a walk through the woods. Never have a listening session spoiled by your earphones again.

It pays to have good connections

In addition to outstanding sound, audiophiles appreciate durable products that are made to last. Here as well, the IE 900 excels.
Gold-plated Fidelity+ MMCX connectors ensure perfect contact. Each termination is seated within a recessed, 4.8 mm-wide socket below the surface of the housing, providing strain relief. The cables themselves are para-aramid reinforced to withstand many thousands of bend cycles. But they don’t have to when protected in the included serialized case.
Connect to practically any digital audio source with the 3.5 mm stereo plug including headphone amps, laptops, and audio interfaces. Each pair of IE 900s also includes symmetrical 2.5 mm and 4.4 mm cables for plugging directly into hi-fi components with balanced outputs. Because when you’re looking for the most natural and immersive sound, every detail matters.

What's in 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

Technical Data

Impedance: 16 Ω
Sound pressure level (SPL): 123 dB (1 kHz, 1 Vrms)
THD, total harmonic distortion: <0.05% (94 dB, 1 kHz)
Cable length: 125 cm
Transducer principle: single dynamic driver, pressure chamber
Weight: 4 g
Technology: unique X3R technology
Housing: One-piece precision-milled aluminum housing
Warranty: global 2-year warranty
Connector: Fidelity (+) MMCX
Ear coupling
Ear canal
Frequency response: 5 Hz – 48,000 Hz (-10 dB)

Features