Astell&Kern AKT8iE In-Ear Monitor

Ace of Bass

Equipment report
Astell & Kern AKT8iE
Astell&Kern AKT8iE In-Ear Monitor

Someday, perhaps as little as ten years in the future, Harvard B-School will do a study on Astell&Kern as an example of how to grow a brand. In 2012, Astell&Kern introduced its first product, which was also the first “premium” portable music player, the AK100. When I reviewed it in 2013, I wrote, “When it comes to pure unadulterated sound quality, the AK100 leaves the iPod, iPhone, iPad, and all their imitators in the dust. Sure, it’s not inexpensive, but for anyone who demands the best sound quality currently available in a portable playback device, the AK100 is the device to own.” Since then Astell&Kern has introduced other, even more expensive players, including its current flagship, the $3999 AK380 Copper.

But how much can a company grow with only one product category? And how far afield from its core products can a company venture without losing identity, focus, or corporate mission? These are the sorts of questions that Astell&Kern was facing a year ago. Its solution was to form strategic partnerships with technological and market leaders to create Astell&Kern co-branded headphone offerings.

Currently Astell&Kern has six universal-fit Jerry Harvey-made in-ears, two in-ears from Final Design, and two headphones and one in-ear from Beyerdynamic, the full-sized over-ear AK T1P, the AK T5P, and the AKT8iE universal-fit in-ear monitor. The AKT8iE, which is the focus of this review, retails for $999 and is the first Beyerdynamic in-ear to miniaturize Beyerdynamic’s latest “Tesla” technology. Astell&Kern is the only source for this in-ear monitor just as it is the only source for universal-fit (as opposed to a custom-fit) Jerry Harvey in-ear monitors.

Technical Tour
Depending on whom you talk with, dynamic-driver-based in-ear monitors are either the best or worst technology for in-ear monitors. Dynamic drivers, as compared with balanced armature designs, have higher mass. Their design requires more power and is therefore less efficient than a BA driver, plus dynamic-driver in-ears often sound “slower” and less detailed in direct comparison with BAs, as a result of having higher-mass diaphragms. But to its credit, a single-dynamic-driver design doesn’t require a crossover, which eliminates all the sonic issues caused by phase shifts at the various drivers’ crossover points. The “best” full-sized headphones are almost all full-range single-driver designs, so why not in-ear monitors as well?

Currently most conventional single-dynamic-driver in-ear monitors are entry-level rather than state-of-the-art, but they are all based on something other than Beyerdynamic’s Tesla technology. The Tesla driver utilizes a ring magnet that has a high magnetic flux density. This higher magnet strength is combined with a new multi-layer diaphragm driver technology that has lower mass and less weight, as well as better damping than conventional dynamic drivers. According to Beyerdynamic, “additional attenuation at the heart of the Tesla driver eliminates even the last traces of resonance in the high-frequency range. Beyerdynamic has also optimized the geometry of the baffle design and replaced the single-layer baffle material with a more stable, high-tech compound. This reduces the vibration of the material to a minimum, which in turn delivers even clearer sound combined with ultra-precise bass.”

What you have with the T8iE is a single-driver system whose performance has been pushed well past what could have been obtained from an off-the-shelf driver motor. The new driver system is housed in what Beyerdynamic calls a “special alloy used in high-tech medical products.” Neither Astell&Kern nor Beyerdynamic published a sensitivity specification, but the T8iE proved to be sensitive enough to be driven easily by the least powerful player I have, my iPhone 5. While I understand Astell&Kern and Beyerdynamic not wanting to release too much proprietary information that could tip off competitors, I do see the lack of detailed technical info about the T81E on either manufacturer’s website as part of the unfortunate and almost universal trend toward publishing colorful prose in lieu of revealing technical information about new audio products.