ZEPHYR is Kotori Audio’s first take at a hybrid driver configuration (1BA + 1DD), making special use of a 10mm Titanium-coated membrane Dynamic Driver.

Through ZEPHYR, Kotori Audio also seeks to explore the advanced implementation of the Pressure-balanced Acoustic System (PBAS), an evolution of a similar system previously utilized in DAUNTLESS.

By employing both the hybrid configuration and the PBAS, we have engineered an IEM possessing a sound that is both technical and tonally balanced for a comfortable listening experience.

ZEPHYR utilizes a hybrid driver configuration consisting of a Balanced Armature driver (BA) and Dynamic Driver (DD).

In combination with the capable Knowles® BA driver, ZEPHYR provides full coverage across the audible sound spectrum.

ZEPHYR’s specially engineered Dynamic Driver (DD) takes advantage of Titanium’s excellent mechanical properties, featuring a lightweight Titanium-coated membrane created through a vapour deposition process. The thin layer of Titanium improves the stiffness of the membrane while keeping the membrane inertia low, resulting in a superior transient response and detail retrieval. The sound produced is extremely quick, clean and with a firm bass.

The coating also serves to reinforce and protect the driver membrane, ensuring longevity and consistent sound reproduction across its lifespan.

Kotori has incorporated a dedicated Knowles® Balanced Armature (BA) tweeter driver specialised in handling the upper frequencies effortlessly, while allowing the dynamic driver to focus its power on the low and mid range, thus reducing the overall distortion of the sound output.

The PBAS is a step up from a similar system previously implemented in the DAUNTLESS In-Ear Monitors. It features an intricate network of acoustic pathways that is integrated into the 3D-printed (3DP) shell structure and the utilisation of a balancer tube for pressure control.

ZEPHYR takes full advantage of the PBAS system to significantly enhance the overall sound qualities of the drivers.

The Balancer tube is a key component within the PBAS, acting to balance the pressure between the front and aft sections of the driver. Its critical dimensions are shaped using a laser cutting process to precisely control the tolerances to under 30 microns (about the width of a human hair).

This level of precision is required to produce inter-chamber pressure relief with a specific rate of pressure change between the front and aft sections, allowing the dynamic driver’s response to be fine-tuned in order to achieve our desired sound signature.

Inter-chamber pressure relief is achieved by bridging the front and aft driver sections through the balancer tube. The pressure equalisation allows the DD to actuate with greater freedom by removing the vacuum pressure at the back vent, lowering the mechanical load on the driver. The result is a cleaner sound possessing an improved transient response, while also eliminating driver flex completely.

The shell of the ZEPHYR has been carefully shaped for ergonomic fitting, geometrically optimised for comfort and stability in the ear, bearing close resemblance to organically shaped custom IEM shells.

The faceplate design features a precisely machined complex surface, taking some inspiration from Bauhaus design to create a unique blended geometrical look.

Returning to our company's roots, we are proud to introduce an evolution of our very first cable, CARBON — now enhanced with modern techniques and materials. Drawing from our extensive
experience of cable-making, Kotori has crafted the ultimate wired experience, blending tradition with innovation.

To achieve this, CARBON 3 utilises silver-plated Oxygen Free Copper (OFC) Litz conductors for the excellent preservation of signal integrity. Combined with a smooth, flexible and durable insulation, the cable is also a step up from its predecessor in comfort and ergonomics. Finally, a gold-plated right angle TRS plug termination further bolsters the overall compact form factor.