JBL Project EVEREST DD66000 User Manual page 11

Project EVEREST DD66000
even-order distortion components. All suspension elements are tailored for
maximum mechanical displacement linearity.
The cone is comprised of a special layered paper pulp matrix with proprietary
Aquaplas ™ damping which offers more pistonic behavior throughout the
woofer's operating bandwidth, and controlled cone breakup beyond it.
A thick wall, cast aluminum frame is used to rigidly support the motor structure.
This fully vented frame and motor design also serves to minimize the
backpressure under the dome and spider, which helps to reduce harmonic
distortion to even lower levels. JBL's Vented Gap Cooling (VGC) is
incorporated within the motor structure, and lowers the operating temperature
of the coil during moments of high power operation.
Altogether these design factors provide reduced harmonic distortions at very
low and high acoustic output, improved power handling, reduced power
compression, and more consistent spectral balance with varying input drive
level.
476Be High Frequency Compression Driver and Horn
See Figure 3
The 476Be High Frequency Compression driver makes use of a 100 mm
diameter, pure Beryllium diaphragm with 99 mm aluminum Edge-wound coil,
operating into JBL's existing Rapid Flare type, Coherent Wave phasing plug.
The use of an efficient Neodymium rare-earth motor structure with new Copper
Sleeved pole piece maintains maximum gap flux and reduced coil inductance at
a minimum size and weight. The combination of these features has created a
driver that can deliver superior sound quality regardless of acoustic power
output with very little distortion and power compression.
Figure 3 – 476Be section view