Development of the A8000 began with reconstruction of physical measurement and subjective evaluation methodologies. Under the subjective evaluation methodology established at the time of its development, the E Series achieved sound quality highly evaluated by many people and became a best seller. With the A Series, a new evaluation index has been incorporated into that subjective evaluation methodology. With the new development of its proprietary Perceptual Transparency Measurement (PTM) evaluation methodology, final has reconstructed the physical measurement and subjective evaluation methodologies of the past in order to realize transparent sound.
*Transparent sound refers to distinct, distantly oriented sound that forms rapidly with the feeling that it is floating in space.
＜Newly developed final proprietary Perceptual Transparent Measurement (PTM) evaluation methodology？＞
Under the subjective evaluation methodology established at the time of D8000's development, the E Series achieved sound quality highly evaluated by many people and became a best seller. With the A8000, a new evaluation index has been incorporated into that subjective evaluation methodology. Among factors that determine sound quality for earphones and headphones, amplitude frequency response is predominant, but there are some sound impression cannot be explained by it. For example, the most critically evaluated aspect of classical music recordings is called transparent sound, a sound impression by which sound is very clear even it is localized at a distant location. We have been considering the realization of this sound impression to be extremely important for becoming uplifted by listening to music. We believe that the high evaluation of our D8000 headphones owes to the realization of such transparent sound. Until now, we have employed modification of the amplitude frequency response, known as tuning, to modify the sound of our earphones, but because it cannot make a great change to time response, it became difficult to achieve transparent sound through tuning. This time, with the aim of achieving transparent sound for earphones, final has developed its own proprietary Perceptual Transparency Measurement (PTM) evaluation methodology. As a result of evaluation and improvement of interrelations between principal components analyzed by the results of subjective evaluation and data analysis of impulse response that could not be gleaned from frequency response in the past, an ideal diaphragm material that is extremely light and possessing high sound speed comprised of ultra-thin Beryllium foil (true Beryllium) has been adopted for the A8000.
＜Adoption of Truly Pure Beryllium Diaphragm＞
The A8000 employs a diaphragm made from ultra-thin Beryllium foil (truly pure Beryllium), which is said to be an ideal diaphragm material due to its light weight and high sound speed. With a specific gravity of 1.85 and a sound propagation velocity of 12,900 m/s, second only to that of diamond, Beryllium has ideal characteristics for a diaphragm material. The adoption of true Beryllium will lead to improved time response that greatly transfigures sound into transparent. The sharpness of sound build-up and the lingering resonance of the sound can be clearly felt, as can the silence between sounds. Crafting thin Beryllium foil is difficult. Our engineers had to struggle to make it stable enough for the product, but it can be said to be a valuable material that pays off our hard works. In order to realize transparent sound through such superior materials, the same high quality has been demanded of the other components of the drive unit as well as the design and manufacturing technology. We have succeeded in leveraging the experience of developing and manufacturing our own dynamic drive unit to draw forth the advantages of truly pure Beryllium diaphragm.
*In the past, a Beryllium diaphragm was created by vacuum deposition of a thin coat of Beryllium onto a resin film. This was effective as an improvement methodology, but the characteristics of the film remain predominant. When true Beryllium is used as the diaphragm material, the sound and characteristics are completely different.
＜“Tetra-Chamber Construction” stainless steel cut chassis＞
The volume and shape of the chambers in front of and behind the dynamic drive unit have a great impact on sound quality. Particularly, operation of the newly developed true Beryllium driver is extremely delicate, and it is impacted greatly by the spaces in the chassis. The internal design of the chassis can be calculated to some extent through simulations, but after that repeated trials of an actual product must be conducted until the sound quality targets are reached. For the A8000, in order to optimize operation of the driver, the inside of the driver unit chassis is divided into four chambers (Tetra-Chamber Construction); the driver ante-chamber and the double construction driver post-chamber and the MMCX connector portion are separated into different chasses. The driver is direct mounted into the ante-chamber of the chassis by a design that suppresses unnecessary vibration to achieve a distinct sound contour. Additionally, the use of four chambers achieves a balance between volume and tightness in the low-range while at the same time preventing leakage of sound.
Please refer to the information below for more details.