JBL Synthesis K2 S9900 - Manual (Page 18)

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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 5dB of increased output above 30kHz. A section view of the 045Be-1
driver is shown in Figure 6.
Aluminum-
Alloy Cover
Aluminum
Edge-Wound
Voice Coil
1" (25mm)
Pure-Beryllium
Diaphragm
Stainless-
Steel
Mounting
Bracket
Phase Plug
Neodymium
Magnet
Gold-Plated
Input Terminal
Figure 6. 045Be-1 section view.
The extremely low mass of the moving system, high magnetic-flux density and
high rigidity of beryllium produce response that is very smooth from below
8kHz to beyond 50kHz.
The response curve has a slight downhill tilt, due to the constant-directivity
nature of the horn used in this system. The Bi-Radial 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 10kHz to 50kHz.