045BE

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The 045Be is groundbreaking in its combination of extreme extension, high output, low distortion and wide coverage. Its development was related to recent advances in recording media. Traditional recording media (CD's in particular) restrict high frequency information to approximately 20khz. The new DVD formats can record information to 50khz and beyond. It was decided during the development of the K2-S9800 that this system would have the capability of reproducing this ultra high frequency information. However, no one had ever attempted such extension in a high efficiency, high output device. The 045Be was developed as a pioneering design to address these requirements.


Tim Prenta
Don McRitchie

Design of the 045Be was the responsibility of Tim Prenta, the Director of JBL Consumer Engineering. The need for high output and efficiency dictated a compression driver device. However, to achieve the required extension, an extremely small and light diaphragm would be required. As with the 435Be, beryllium proved to be the most suitable material. Tim specified a 1" diaphragm that has a weight of only 0.1 grams. To keep the total moving mass low, the coil is attached directly to the diaphragm without a former. The complete assembly weighs only 0.3 grams. High efficiency was accomplished with an extremely powerful, but small neodymium magnet that provides a flux density of 20 Tesla in the gap.

The small diaphragm and need for extreme extension dictated the requirement for an inordinately precise phase plug. The only process that proved capable of meeting the tight tolerances was stereo lithography. Normally, this technology is only applied to the development of prototypes due to the high costs involved. However, every production phase plug made for this driver is produced using this technique since no other suitable means could be found.


0435 Cross-Section
Harman International

The result is a driver with minimal distortion levels and a frequency response that is essentially flat from 10khz to 48khz. It has extraordinary output, capable of sustained levels over 110db. Used with the UHF horn designed by Greg Timbers, it is able to provide uniform coverage over a 60 horizontal angle and 30 vertical angle for its entire bandwidth. All of this in a package that weighs less than 1lb.

2004 Don McRitchie
based on information provided
by Tim Prenta