As part of the SEAS Excel range, the Dark Diamond tweeter - SEAS ref. E0101 T29D002 - benefits from all the recent optimizations implemented by the company. Through 2018 and into the spring of 2019 the diamond tweeter was optimized by the Norwegian high-end transducer manufacturer for better performance in the 1-40 kHz frequency range and with improvements in the production processes as well. This included obtaining higher linear excursion with lower distortion at low frequencies, smoother response and better batch-to-batch consistency.
The White Diamond model was originally launched in 2013. It has undergone steady development over the years while also receiving high appraisal in the market and found a steady sale to ultra-high-end customers around the world. In the earlier years, the quantities were so small, they were essentially all produced by SEAS' own R&D tweeter engineer, Tore Tambs-Lyche, who is now retired. Increased demand and long delivery times meant SEAS had to look at the production setup.
To facilitate this development, SEAS has invested more than 300 hours of engineering, as well as in a new Brüel & Kjær NEXUS conditioning preamplifier which is linear to above 100 kHz, and a Benchmark AHB2 analog power amplifier (read the audioXpress review here) with low distortion and low noise well beyond 100 kHz, such that the entire measurement chain is geared towards high-res and high-frequency audio measurements.
The T29D002, “Dark Diamond” is a 26mm pure Diamond dome tweeter with a patented E0101 neodymium based magnet system. The Diamond material is extremely stiff, making it the natural first choice in dome materials. It works as a perfect piston all the way to 45 kHz. This very high break-up frequency of the dome keeps the distortion far away from the audible range for unprecedented sound.
The unique HEXADYM patented magnet system is based on 6 radially magnetized NdFeB magnet blocks. This design provides efficient ventilation and damping of every potentially resonant cavity behind the dome, surround and voice coil. Precisely mounted copper sleeve reduces inductance and lowers nonlinear and modulation distortion. The fine cuts of the acrylic rear chamber help scatter the internal sound waves with a minimum of damping. Together with the non-resonant magnet system, this provides the high dynamic response and clarity of the tweeter.
The homogenous, FEA-optimized linear surround manufactured by SEAS from SONOLEX, is a lightweight fabric with high consistency and climatic stability. For the launch of the Dark Diamond, the design was optimized regarding symmetry and excellent mechanical linearity for low distortion also at low frequencies and high input power. A high temperature voice coil wound on a titanium former is applied for optimum transfer of force from the coil to the dome and for minimum losses, maximum transparency, lowering distortion and high thermal power handling. Flexible lead-out wires ensure a good connection between voice coil and terminals.
This arrangement also helps to prevent lead breakage due to the large excursions encountered when low crossover frequencies are used. The short coil underhung system ensures large linear excursion with low distortion.
The combination of low mechanical and electromagnetic damping ensure high quality reproduction and brings out even the finest micro details in music. The magnet and coil geometry determine a linear Xmax of ±0.8 mm, while the linearity of the suspension is at least twice this value.
For distribution (DIY), the Dark Diamond tweeters are packaged in pairs.