The ND1050 one inch exit high frequency compression driver is designed for high quality applications, where size is a critical issue. ND1050 high flux ultra compact magnetic assembly architecture, achieves the remarkable 1,9 Tesla value in the gap containing the external size in 75mm - 3 inches - making this HF driver a benchmark in its category. Equipped with Eighteen Sound proprietary Phase Plug architecture, the ultra compact ND1050 ensures a coherent wavefront at the horn entrance over all the working frequency range. The radial - tangerine phase plug design with short openings and high flare rate value assures low distortion and remarkable improvements in mid-high frequency reproduction. The transducer diaphragm assembly is composed of a titanium dome sandwiched to a proprietary treated polyester suspension. This design maintains low resonance and lowers the minimum crossover point value to 1.6kHz. An edge-wound aluminum voice coil, wounded on proprietary treated Nomex, completes diaphragm assembly. Thanks to its physical properties, the proprietary treated Nomex former shows 30% higher value of tensile elongation at working operative temperature (200°C) when compared to Kapton. Moreover, this material is suitable to work also in higher moisture contents environments. The ability to perform properly under inclement weather conditions is a key-point of the Eighteen Sound philosophy. The special treatment applied to the magnet and the top and back plates of the magnetic structure makes the driver more resistant to the corrosive effects of salts and oxidization than any other treatment used by other manufacturers.