A lightweight, high-rigidity anodized aluminium dome diaphragm is used for the tweeter diaphragm. The driver reproduces a wide frequency range up to 100 kHz by using a new dome shape optimized through simulation, as well as achieving greater uniformity in phase characteristics by using a phase plug. In addition, the SB-G90 uses high-linearity-drive underhung voice coils, the magnetic gaps of which have had magnetic fluid injected to suppress temperature rise, thereby ensuring superior power linearity. These features provide reproduction of the high-frequency range with superb detail and beauty.
As with the tweeter, the mid-range also uses an anodized, lightweight, high-rigidity aluminium cone diaphragm. The magnetic circuit achieves low distortion and enhanced drive power by using large magnets, copper caps, and high-linearity-drive underhung voice coils. Also, the support structure provided by the tough die-cast frame has resonance-dispersing arms, thereby thoroughly eliminating even the slightest unnecessary resonant sound. These features enable mid-range reproduction with excellent precision and response.
In addition, the mid-range diaphragm uses a cone shape in which its sound generation centre in the axial direction is closer to the sound generation centre of the tweeter, and the position of the axial direction of the dome tweeter placed in the centre of the mid-range diaphragm is precisely adjusted, thus achieving linear phase reproduction by integrating the sound in each range without time lag. Also, the inside end of the mid-range diaphragm has a smooth shape so there is no deterioration of tweeter sound characteristics, with the diaphragm being constructed to deliver the sound emitted from the tweeter directly to the listening space. This reproduces mid-range and highs with superb precision and response, as well as excellent clarity in sound imaging.