TEMPTATIONS

Sennheiser IE900: “impressively clear and open sounding” premium wired in-ears

FOR

• Detailed, articulate sound

• Refined yet entertaining presentation

• Clever engineering

AGAINST

• Cable transmits noise on the move

• No in-line remote

VERDICT

Sennheiser’s

IE 900 combine listenability, insight and comfort, making them one of the front runners at this elevated price

Sennheiser’s new IE 900 in-ear headphones are a purist design, engineered with the singular purpose of offering the best sound quality possible at this level. Their technical highlights include a single 7mm drive unit per earbud, an intricately machined aluminium casing, and the use of some clever resonance chambers inside that casing to improve the driver’s frequency response.

New premium wired in-ears are far less common than they used to be, and understandably so. In-ears have always been about portability and ease of use, so the rise of wireless connectivity makes perfect sense for such a product. Add complementary technologies such as noise-cancelling and app control into the equation and the ideal features template for such headphones looks set.

Yet this template doesn’t put sound quality front and centre. And if that’s paramount to you, then fully wired remains the way to go – and, with that, all the flexibility and convenience features go out the window.

“They’re impressively clear and open sounding, able to dig deep into the production of a recording”

CAREFUL SHAPING

High-end in-ears invariably suffer from low perceived value. It’s hard for a manufacturer to make something like the IE 900 look and feel as expensive as they are. But Sennheiser has given it a good go.

The IE 900s are packaged in a neat box and come with six pairs of ear tips that are split evenly between silicone rubber and memory foam. There are three 1.2m-long cables; one has a standard 3.5mm plug and two are balanced with 2.5mm and 4.4mm ends respectively. Disappointingly, there’s no sign of an in-line remote on any of them.

It’s on the inside where Sennheiser’s work is most apparent. The engineers have chosen to go with a single driver rather than the more fashionable multiple unit approach that many rivals take. The advantages of this simpler approach are improved cohesion and better phase performance. A single unit has no need for a crossover of any sort, so avoids the innate distortion of such a circuit.

Having just one drive unit to cover the entire frequency band (5Hz-48khz) promises a seamless sound, but it’s also hard to design one that has a suitably even response.

Sennheiser’s solution is two-fold. Firstly, the 7mm diaphragm is made of a blend of polymers in a bid for rigidity and low resonance. But not all the resonances can be controlled this way, so three Helmholtz resonator chambers have been machined into the aluminium case structure. These operate in the 6.5-10khz range and absorb the driver’s excess energy at these frequencies, leaving a much more even balance. Even the tiny port that feeds the driver’s sound into the ears is specially shaped to control the frequency response.