The A4000 to achieve the impossibly high-quality sound for this price range requires new development and production facilities. The 6mm diameter dynamic driver requires new parts and a total redesign of everything, including the production machinery. Sound design was conducted based on Final's proprietary sound evaluation method established during the development of Final's flagship A8000 model. It achieves “transparent sound,” which means an impression that even sound images localized distantly can be heard clearly, for various genres of music.
Achievements of a new sound quality evaluation method
The development of the A series began with establishing a new sound evaluation method by analyzing the relationship between sound quality and physical characteristics. The results came to fruition with the A8000, and the sound evaluation method evolved further with the A4000. Final listen to music recorded at various qualities at various sound levels. However, conventional evaluation methods generally entail a subjective evaluation under the fixed conditions such as constant sound pressure level and an evaluation method that takes into account the various practical listening conditions that could actually occur when users evaluate the sound of various products of earphones that didn’t exist. Final believe that researching a sound evaluation method that made it possible to arrive at a realistic evaluation even under various listening conditions made it possible to bring a product that can be said to be the new standard for this price range.
Redesigned [f-Core DU] Driver Unit
In order to achieve sound quality impossible at this price range, Final newly developed 6mmφ [f-Core DU] dynamic driver unit from scratch. To realize the brand new driver, Final established a new production facility overseas and newly designed parts for the driver unit such as diaphragm, voice coil, magnet, magnetic circuits, adhesives, and the production machinery used in the manufacturing process. As the material for the driver front housing, rather than the traditional aluminum, we used brass, a material that is both highly resistant to the effects of magnetism and also boasts a high specific gravity. In order to increase the time response characteristic of the diaphragm, the voice coil employs a 30μ ultrathin CCAW, and a minimum of adhesive is used for assembly to thoroughly lighten the moving parts. Moreover, the diaphragms are neatly pressed in small lots of roughly 1/3 the normal size in order to constrain pressure deviation to a minimum and realize uniformly shaped diaphragm with no deformation.
The Feeling of a Customized Fit
Based on the chassis design that serves as an ideal solution for the IEM that become established during the development of the B Series, the A4000 realizes a superior sense of fit. Whether or not earphones offer a superior sensation of fit is determined by the sensation of oppression. While at first glance it may seem correct to select an ergonomic shape and hold it in place with the elasticity of silicone, this always places pressure on the ear, which creates an unwary burden and leads to the accumulation of fatigue. By limiting the area that comes in contact with the ear in contrast to an ergonomic shape that comes in contact with a large area of the ear, this product aims to achieve a sense of fit with no feeling of oppression. The green section of the diagram below (earpiece) is the 1st position, the blue section (Tragus) is the 2nd position, and the pink-colored section (cavity of the concha) is the 3rd position which contributes to the ultimate stability and fitting. For that reason, it is suitable for the ears of many different people. To the extent that there is no feeling of oppression at any of the points of contact, that makes for such a comfortable, superior feeling of a customized earphone fit.
2-Pin connector + original OFC cable
The 2-Pin connector is a high precision part that was developed in-house. The plug employs the highest versatility φ0.78 standard. The cable employs soft, supple coating material designed with consideration to touch noise and bends flexibly when used in conjunction with an ear hook to achieve a good fit.
Ear hooks that alleviate cable touch noise (incorporates lock mechanism)
An ear hook is effective in reducing touch noise; wearing it when walking dramatically reduces the unpleasant rustling sound that may occur when the cable rubs against the body (cable touch noise). In the past, Final’s ear hooks have characteristically been slimmer than ordinary and virtually indistinguishable from a wire or rosin-filled cable, making it so comfortable that it is easy to forget that one is even wearing it. This is the type with an affixed lock (B Type) that is capable of holding the cable firmly in place.
Original ear tips with a color difference between the left and right bushes.
Two types of silicon differing in rigidity are employed for the sound conduit and for the earbud that comes into contact with the user’s ear. The silicon used for the sound conduit is more rigid than that used for the earbud, and by having groove processing is applied to it, it combines both strength and flexibility. Soft silicon has been employed for the earbud, making for a comfortable fit and a high level of sound insulation. One of the bushes is gray, while the other is red; by pulling the earpiece back slightly to check the color of the bush, it is easy to distinguish between left and right, even in places with subdued lighting. Since the bush colors of neighboring sizes are different (the gray bushes alternate between dark and light gray; the red bushes alternate between red and pink), it is also easy to distinguish between sizes.
Silicon carry case
With this silicon carry case, the cables can be rolled up and stored easily. The earphones themselves are gently secured using thin dome-shaped silicon covers.