JBL manual Project EVEREST DD66000, 045Be-1section view

Project EVEREST DD66000

These features, when taken as a whole, create a new large format compression driver with the greatest high frequency extension, lowest distortion, smoothest response and greatest sonic detail.

045Be-1 Ultra-High Frequency Compression Driver and Horn

Like the 045Be, the 045Be -1 uses a 25-mm beryllium diaphragm and 50-mm neodymium magnetic structure. The pure beryllium diaphragm is less than 0.04

mmthick and has a mass of only 0.1 gram. The single layer aluminum ribbon voice coil is wound without a former and attached directly to the diaphragm. The driver employs the smallest annular slit phasing plug that JBL has ever designed. The 045Be -1 has been redesigned to improve manufacturing yield and consistency. Small changes have been made to the top plate and some significant improvements were made to the surround shape and clamping methodology. As a result, the driver has picked up nearly 5 dB of increased output above 30 kHz. A section view of the 045Be-1 driver is shown in Figure 4.

Figure 4 – 045Be-1 section view

The extremely low mass of the moving system, high magnetic flux density and the high rigidity of beryllium produce response that is very smooth from below 8 kHz to beyond 50 kHz.

The response curve has a slight down hill tilt due to the constant directivity nature of the horn used in this system. The horn is properly scaled to maintain a coverage angle of 60 degrees in the horizontal plane and 30 degrees in the vertical plane over the frequency interval from 10 kHz to 50 kHz.