Review: Astell&Kern Pathfinder

Hybrid IEM Redefined

New levels of hybrid driver innovation to deliver better-balanced sound

The Pathfinder in-ear monitor is the second collaboration between Astell&Kern and Campfire Audio, a U.S. designer and manufacturer of premium hand-built earphones. Astell&Kern is no stranger to headphone collaborations, having previously partnered with brands like Beyerdynamic, Jerry Harvey Audio, and Final Audio.

The Pathfinder delivers several firsts in audio driver technology: it is the world’s first Dual-Diaphragm Mid-Focused Balanced Armature (BA) Driver from Knowles, to achieve a more natural reproduction in the mid-range area. To elaborate, this all-new design houses two chambers with separate diaphragms and a drive rod actuated by a single coil, which in Astell&Kern words is like a twin-cylinder engine to deliver more horsepower and smoother operation compared to a single larger piston.

It is also the first earphone to employ Campfire Audio’s new Radial Venting Technology for dynamic drivers to deliver more powerful bass and a larger soundstage. Finally, it employs Campfire Audio’s patented Tuned Acoustic Expansion Chamber technology (T.A.E.C.) technology to allow the custom-dual BA drivers to deliver clearer and more precise high-frequency reproduction.

To pack so many drivers, the shell is understandably chunky. The interior acoustic chamber is 3D printed, designed to allow the drivers to vent and deliver optimum sonic performance. Assembled by hand in the USA, the shell consisted of a stainless steel spout, an aluminium body and the iconic hexagonal faceplate in aluminium. The silver-plated copper flat cable hooks around the ear to hold the weight well and to prevent tangling. The retail package includes three cables of 2.5mm, 3.5mm and 4.4mm plugs, and connects to the Pathfinder earbuds via custom Beryllium copper MMCX connectors that are harder than typical brass material for better durability.

The size, I must say, is worth it. The three dual drivers present a massive amount of musical detail that overwhelmed my senses. The balanced tuning allows the treble to deliver its needed bright tonality while the midrange instruments play with an uncanny presence which adds to the tonal precision. The mid-bass pumps politely without exaggeration like a true gentleman, and while it will not satisfy bass lovers, it is a necessary balance to avoid frequency wars. The package comes with dozens of ear tips and materials that subtly influence the frequency balance, so one should swap around.

One outstanding characteristic that makes the Pathfinder so impressive is that there is no excessive prominence of one frequency range over the other. Every instrument is able to be heard clearly, whether it’s a bass guitar, a Rhodes piano, a saxophone, or even a vocalist. It helps that the sound staging keeps the instruments layered and spread intimately to the sides of the ears to increase listening attention. It sounded as if each instrument had its own individual driver to play the sound without fighting over one another.

There is probably just one drawback during my audition: instruments like the tambourine do not sound as crisp as other bright-tuned earphones like the Meze Audio ADVAR which we reviewed in the last issue. The ADVAR offers a different presentation that has its merits – like a wider airier sound – but technically, the Pathfinder delivers more audio information without the clutter.

Rating: 4.5
We Say A technically outstanding pair of IEMs that rewards musically-demanding listeners.


Technical Specifications
Transducer Type [High] Custom Dual Balanced Armature Drivers + T.A.E.C. / [Mid] All-New ‘Dual Chamber’ Balanced Armature Driver Technology from Knowles / [Mid-Low to Sub-Bass] All-New Dual Custom 10mm Dynamic Drivers paired with Radial Venting Technology
Frequency Response 5 – 20,000 Hz
SPL 94dB @ 1kHz 13.49mVrms
Impedance 6.2 Ohm @ 1kHz