TAD has fine-tuned its existing ET-703, known as a true rear compression type horn tweeter with this triple-slit fading plug. The 35mm beryllium diaphragm is extremely lightweight at only 0.07gr, and in synergy with the aluminum edge-wound voice coil insulated with an anodized aluminum coating film, combines outstanding response with a wide frequency bandwidth and high input power. The phasing plug is triple-slit type with slit spacing of approx. 5 mm, enabling reproduction up to 45kHz. The magnetic circuit is provided by a samarium-cobalt magnet that can ensure stable output even in high-temperature operation, and the magnetic flux density can reach 2 Tesla.
According to TAD, with its triple-slit fading plug, 15W rated input power (30W max.), and 5kHz or higher crossover frequency (-12 dB/oct or higher), the new ET-703a horn tweeter will further revolutionize the world of precision monitoring and high audio design. "The ET-703a is one of the world‘s most efficient and broadband reproduction loudspeakers for super high frequencies. Using our unique vacuum evaporation technique, we have succeeded in integrating the surround and diaphragm with beryllium. By designing the resonance frequency of the surround higher than 50kHz, the negative effects on the audible frequency band are eliminated. Furthermore, despite the large 35mm diaphragm, the diaphragm is ultra-lightweight at 0.07 g, and the high resonance frequency is as high as 45kHz. As a result, a wider reproduction bandwidth, excellent transient characteristics, and outstanding resolution are achieved," the company states.
Perfecting the original design of this rear compression type horn tweeter, TAD hollowed out the inside of the pole yoke to create a sound path and mounting the diaphragm from the rear. This method ensures ideal phase equalization up to the ultra-high frequency areas. The effect of surround vibration is minimized, resulting in a transparent and smooth extension to the high-frequencies.
TAD also applied a triple-slit phasing plug, which was computer-designed, offering improved equalization characteristics to ensure a smooth frequency response up and above 30 kHz. The surfaces of the phasing plugs are also finished by high-precision machining with a tolerance of 20μm to ensure consistency. This, according to TAD engineers, results in the very high resolution reproduction that characterizes this type of super high frequency drivers.
A voice coil of edge-wound wire made of anodized pure aluminum increases the efficiency of the magnetic circuit, while heat-resistant materials and adhesives used in the voice coil bobbin ensure stability to withstand the large maximum input power of 30W.
Rare earth samarium-cobalt magnets with high magnetic energy are built into the limited volume of the super tweeter. Its powerful magnetic characteristics, combined with the electromagnetic soft iron showing extra low carbon and low impurity used for the pole yoke and plate, constitute an ultra-strong magnetic circuit with a magnetic flux density of 2 Tesla and a total flux of 40x10-4 Wb.
TAD Loudspeakers and Drivers
Technical Audio Devices (TAD) was originally the name given to a project launched by Tokyo-based Pioneer Electronic Corporation (currently Pioneer Corporation) in 1975 to develop high-end speakers for professional use, advised by Bart Locanthi in the United States. Nearly 30 years after the first TAD-branded speakers were released, Technical Audio Devices Laboratories was spun off from Pioneer Corporation in 2007 as a company dedicated to developing and marketing a broader range of TAD-branded products. Its "Professional" division offers a range of OEM drivers that have been embraced both by enthusiast speaker builders and manufacturers in the studio monitor and high end audio markets.
www.technicalaudiodevices.com
