TENORA is the successor to the previous model, 9iNE. With updates to its housing design, materials, and driver tuning, it has evolved into a brand-new model. In this blog, we’ll dive into the details of TENORA, compare its sound with other models, and explore the materials used for the rear housing backplate. For orders and basic product information, please visit the product page below.
Housing:
One of the most significant changes from the 9iNE is the updated housing design and materials.
Front Housing: Aluminum (semi-matte black anodized finish), partially stainless steel.
Body Housing: PLA resin (3D printed), partially stainless steel.
Rear Housing: Various types of wood, stainless steel, brass, and copper.
The front housing is made of aluminum and features a semi-matte black anodized finish.
Aluminum is characterized by its low density, which results in a high sound propagation speed (elastic modulus/density). Its lightweight and high sound propagation speed make it ideal for fulfilling one of the key requirements for a front housing: transmitting vibrations with minimal loss. However, its low internal damping rate means that it absorbs vibrations less effectively, making it less suitable for the driver mounting area, where suppressing vibrations from the dynamic driver is essential.
To address this weakness, stainless steel is incorporated into the driver mounting area to absorb vibrations. This design is also utilized in the titanium-bodied LOAK2 model. In the image below, the blue section highlights where stainless steel is integrated. Additionally, a resilient material is placed between the driver’s side and the aluminum housing. This material applies constant pressure to the driver, ensuring it remains securely in place and minimizing the transmission of vibrations to the front housing. As a result, this design achieves clear, stable sound and maintains solid bass performance akin to that of a stainless steel housing.
As with the previous 9iNE model, the front housing of the TENORA is designed to position the dynamic driver as close to the ear as possible. Compared to the MIROAK-II and LOAK2, the distance from the driver to the sound outlet in the TENORA is significantly shorter. This design takes full advantage of the compact driver, minimizing sound attenuation over distance.
The body housing shares the same design as the MIROAK-II JAPAN Limited model, but with a material change: instead of ABS resin, PLA resin is used. PLA is harder than ABS, but it has lower rigidity. In practical terms, this means it is less prone to deformation.
Since the TENORA’s driver material is not as rigid as that of the MIROAK-II, overly soft materials at the rear of the driver could result in excessive mid-to-low frequency volume, compromising the clarity and definition of the mid-to-high frequencies. To address this, PLA resin, which is both resistant to deformation and easier to mold, was chosen for the rear body. To reinforce the structure, a stainless steel ring is used to secure the rear body’s backplate.
Sound:
TENORA’s base sound, like the previous 9iNE, is characterized by the delicate, detailed qualities unique to a small driver, a slightly thicker low end, and a slimmer mid-to-high range. However, the biggest difference from the old 9iNE is that the mid-to-high range now has greater resonance, and the closed-in, slightly dark soundstage of the 9iNE has been improved. There’s a newfound sense of openness in the upper range, along with brighter and lighter mid-to-high frequencies. As a result, the overall balance across low, mid, and high frequencies has improved, making TENORA more enjoyable to listen to.
Comparison of sound with MIROAK-II:
Although TENORA and MIROAK-II share similar housing designs, their core dynamic drivers differ in size and diaphragm material, resulting in distinctly different sonic characteristics.
Because TENORA uses a smaller driver, it’s more reserved in terms of volume, impact, scale, and dynamics compared to MIROAK-II. In return, it offers standout listening comfort, causing less fatigue, and the sound is generally less forceful than MIROAK-II.
If we were to describe the MIROAK-II’s sound as “dynamic, energetic, and masculine,” TENORA could be described as “gentle, beautiful, and feminine,” with a soft, pleasant tonal quality. In particular, female vocals tend to sound smoother and more comfortable to the ear when played through TENORA.
Regarding the Backplate Material:
As with our previous models, the backplate—which forms part of the rear housing—can be chosen from either wood or metal. There are dozens of wood options available, each offering subtle variations in sound quality based on factors such as density, hardness, and oil content. Depending on the wood selected, you might experience a clearer sound, increased warmth, or a slight boost in bass or overall sound pressure. However, these changes typically only affect about 10–30% of TENORA’s overall sound character and do not drastically alter its core sound signature.
On the other hand, comparing harder woods with softer ones can reveal slight differences in tonal tendencies. This means you can enjoy the process of selecting a wood or metal that suits your personal sonic preferences, customizing the sound to your liking. This selection process itself is one of the special appeals unique to TENORA.
I have created three demo units using Snakewood, Honduras Rosewood, and Spalted Maple (Itaya Kaede). I also made my personal TENORA with Ezoyamazakura (Ezo Cherry), giving me four demo units in total, each featuring a different wood hardness.
When comparing these four TENORA units, each type of wood imparts subtle sonic differences. Snakewood offers the slimmest and sharpest sound profile, whereas Honduras Rosewood is slightly warmer, thicker, and milder in comparison. Spalted Maple provides an even softer, more gentle tone, while Ezoyamazakura delivers the richest and warmest low-end among the four.
In terms of sound impressions, you may notice a progression from sharper to more mellow, and from cooler to warmer tones, in the order of Snakewood → Honduras Rosewood → Spalted Maple → Ezoyamazakura. The variations are subtle, but listening to each one highlights the unique sonic shifts brought about by different materials.
TENORA’s fundamental sound characteristics and response graphs are based on Honduras Rosewood, which has a standard level of hardness and density among the woods I use. Therefore, when selecting a wood backplate, it helps to think about how you want to shift this “reference sound” in order to achieve your ideal tone.
On the other hand, for those choosing a metal backplate, please note that I incorporate a high-rebound material on the inner side of the plate. This design differs from the inherent rigidity of metal, resulting in a more pronounced low-end. You can thus enjoy the characteristic of metal while also benefiting from richer bass performance.
