Brass housing integrally machined ear pieces
At final, we refer to the Piano Forte series with its uniquely shaped sound conduits that have no silicon ear pieces as being "canal open type". With the slightly protruding sound conduit, sound from the diaphragm is fully conveyed to the audio canal, and a superlative fit can be obtained while maintaining the sense of openness of open-type models.
The pivot of sound quality in the Piano Forte series lies in this aperture. With ordinary canal type earphones, silicon ear pieces are used to seal the audio canal. By sealing the audio canal, which connects the diaphragm and the eardrum, it is possible to reproduce even the lowest sounds; in turn, the diaphragm is exposed to high pressure and distortion occurs. At the same time, the silicon ear pad closing off the audio canal moves in much the same way as the diaphragm does. The more the hermetic level is raised and the greater the sound insulation properties, the greater the distortion and resonance sound, and dull bass tones and a feeling of distortion adheres (clings) to the music. With the Piano Forte series, silicon ear pieces have been eliminated, and the section of the product inserted into the ear canal has been machined as a single piece with the product. Natural sound with a sense of openness to it has been achieved.
Usually with earphone reproduction, sound seems to play inside the user's head. With the Piano Forte series, the sound that is emitted passes through space to the user, making it possible to experience a natural way of hearing sound. But using a canal type earphone driver unit - which assumes the sealing of the audio canal – without silicon ear pieces makes for sound that does not bear listening to. To eliminate the silicon ear pieces, it was necessary to develop a variety of technologies, including a large aperture driver unit.