“With the IE 900, we want to create an intense listening experience, allowing the listener to explore the deepest corners of their music collection, anywhere” – Jermo Koehnke, Product Manager, Sennheiser.
The One-Driver Principle
Instead of a multi-driver system that introduces phase incoherence and unwanted distortion, Sennheiser has improved the one-driver principle. Based on this philosophy, the German audio brand developed their 7 mm TrueResponse transducer which can be found in various forms throughout Sennheiser’s professional and consumer-focused in-ear ranges. The deployment of a single, high-performance dynamic driver completely avoids the sonic obstacles introduced by alternative multi-driver arrays: phase incoherence and the subsequent distortion borne from the overlapping frequency bands of the driver-crossover mechanism.
Refined for Accuracy
Developed with an audience of high-fidelity sound enthusiasts in mind, the IE 900 makes even the subtlest nuances of sound audible. This reproduction of a wide frequency range with low distortion is the result of Sennheiser ́s one-driver principle and the development of their X3R system, a refined version of the company’s own, in-house developed and produced, 7 mm TrueResponse transducer. What refines the X3R technology is the three Helmholtz resonator chambers which are precision-drilled into the elegant aluminum chassis of the IE 900 and placed between the diaphragm and the nozzle. To further smoothen the treble, Sennheiser integrated an acoustic vortex. This is a complex shape that maximizes acoustic friction so that excessive energy is scattered. The effect is measurable and audible and serves to make the treble as smooth and pleasing as possible.
“The X3R system enables the listener to hear more details in their music which is what audiophile listening is all about. The three resonator chambers smoothen the frequency response at high frequencies in the area from 6 to 10 kilohertz, reducing the so-called masking effect. This means that you can better hear frequencies above 11 kilohertz – the details”, says acoustic engineer at Sennheiser, Andre Michaelis and continues, “the challenge here is to perfectly balance the three chambers to get the correct response. You need to tune chamber by chamber and then make sure they are perfectly balanced together to achieve the correct frequency response. This process requires advanced acoustic engineering”, Andre Michaelis adds.
Tuned Like a Sports Car
This complete harmony of systems is at work to unlock the details buried within every track. That each earpiece houses three resonator chambers, pinpoint and tame the resonance peaks that mask a recording’s unique textures. The frequency smoothing brings the listener ever closer to a perfect sound experience—the reproduction of an entire moment captured through sound. Further, the process of milling each aluminum earpiece yields unmatched precision of the Helmholtz resonators for maximum effectiveness of the resonator system.
According to Jermo Koehnke, Product Manager at Sennheiser’s audiophile team, it is the tuning of the X3R systems resonator chambers that make the IE 900 truly stand out and why they offer such exceptionally good high frequency translation.
“With the IE900 our engineering team managed to bring the potential of our 7 mm transducers to their full potential. The IE 900’s affinity for detail is striking. The clean and balanced sound signature stays honest to the original recording—even on tracks whose secrets you thought you had exhausted. The IE 900 gives you the best frequency extension and lowest possible distortion within the in-ear category”, Jermo Koehnke adds.