cast aluminum alloy frame. This pro-
vides accurate, rigid support for the
motor and cone mounting points, as
well as doubling as a massive heat sink
by providing a huge surface area for
heat dissipation.
Instead of the conventional single pole
piece thermal vent, the 1500AL h a s
three separate gap cooling ducts which
more effectively cool the voice coil
and reduce the likelihood of hot spots.
By reducing the operating temperature
of the voice coil, power compression is
significantly reduced, which enables
the low frequency driver to operate in
a more linear fashion over a wider
sound pressure level (SPL) range.
The voice coil itself is constructed
from edge wound Aluminum wire on a
massive 4-inch in diameter Fiberg l a s s
f o r m e r. This configuration provides for
further cooling ability in conjunction
with the motor design.
The Aquaplas™-coated cone along
with EPDM Rubber Surround provides
excellent damping and transient
response characteristics.
435Be Beryllium diaphragm/
Neodymium magnet High Fre q u e n c y
C o m p ression Drive r
See Fi g u re 4
The 435Be neodymium high frequency
compression driver is based on the pro-
fessional JBL2435 device. It incorpo-
rates a rare-earth neodymium magnet
structure, designed by extensive com-
puter modeling, including finite ele-
ment analysis, which combines the
attributes of eff i c i e n c y, strength, low
mass and compact size. This motor
structure is coupled with a 3-inch
Beryllium diaphragm. Beryllium pro-
vides improved low distortion and flat
frequency response over Aluminum or
Titanium, thanks to its higher stiff n e s s -
to-mass ratio. This diaphragm is dusted
with Aquaplas™, JBL's proven acousti-
cal damping material, to reduce
breakup and smooth out natural
response irregularities.
High temperature materials and adhe-
sives allow the driver to handle ex-
tremely high power levels over extend-
ed periods of time. The SonoGlass™
horn is acoustically inert and precision-
molded to exacting tolerances. It incor-
porates a unique tubular energy trans-
mission system.
045Be Beryllium diaphragm/
Neodymium magnet Ultra-High
F requency Compression Driver
See Fi g u re 5
The 045Be utilizes the same principles
and materials as the 435Be, in a smaller
footprint so that a frequency response
up to 50 kHz can be achieved. T h i s
transducer was developed specifically
for the K2 S9800.
I n t e rnal Cro s s over Netwo r k
Each loudspeaker unit has three internal
dividing networks, one for each trans-
d u c e r. Ultra high frequency, high fre-
quency and low frequency signal paths
are completely independent to reduce
any possibility of crosstalk or interfer-
ence from the relatively large capaci-
tors and inductors.
8
Project K2 S9800
