The CST (Coherent Source Transducer)has enabled us to achieve our goal forthe TAD Compact Reference: reproductionwith controlled directivity over a widerange from a single point with uniformphaseﾓ. The design of the midrange cone is based on detailed calculations, so not only does it have superior acoustic characteristics, it also controls the directivity performance of the tweeter due to the concentric configuration. This unifies the acoustic center of the tweeter and midrange and reconciles the phase and directional characteristics through the crossover range. The CST Driver is thus a large step forward for coaxial speakers, enabling ultra wide range reproduction of 250Hz to 100kHz, accompanied by a directivity pattern which neatly dampens without disruption across all bands. The result is extremely clear and stable imaging, a wide frequency response and incredibly rich and natural sounding reproduction.
The tweeter dome and midrange cone are made of beryllium, the lightest and most rigid of metals, which makes it a superior diaphragm material and one which boasts a history of more than 30 years of TAD achievements. The diaphragm is produced using a vapor deposition technique developed by TAD and refined over many years. It provides strength and uniformity, combined with high internal loss, for smooth superior performance. The tweeter diaphragm shape derived by using an advanced optimization method based on HSDOM (Harmonized Synthetic Diaphragm Optimum Method) computer analysis. It accurately controls differential vibration produced by the diaphragm and moves it out of the audible band, providing response to as high as 100kHz. The large midrange cone features a direct radiation, vapor deposition beryllium diaphragm. The resulting sound is astonishingly transparent, direct and precise across a wide frequency range.
The CST Driver is mounted into a high-stiffness enclosure that is precisely shaped to minimize the diffraction of the radiated sound. In order to maximise the capability of the CST driver, we developed new ISO (isolation) technology. This involves including a mechanism to block vibration from the driver unit entering the enclosure, thus structurally separating the CST Driver from the enclosure. The CST Driver with its powerful drive capability is prevented from exciting the enclosure, thus reducing the radiation of secondary sound. It also limits the influence of the energy from the powerful bass drivers. Delivering only sound radiated from the CST Driver diaphragm improves resolution to convey accurate detail, allowing, for example, the differences in tone color that vary subtly according to how the performers play or sing to be heard with unmatched clarity.