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SOPHISTICATED CIRCUITRY
D i v i d i n g n e t w o r k s a r e used i n t w o - w a y l o u d
speaker systems to electrically channel l o w tones
to the bass loudspeaker and h i g h notes and over
tones to the h i g h frequency transducer.
I f a d i v i d i n g n e t w o r k is to f u l f i l l i t s f u n c t i o n w i t h
out compromise, i t m u s t be able to handle extreme
v a r i a t i o n s i n dynamics, the f u l l range of audio
frequencies, complex t r a n s i e n t s , and the v a r y i n g
impedance o f a loudspeaker load.
J B L d i v i d i n g n e t w o r k s are carefully designed to
complement the exact characteristics of the J B L
transducers w i t h w h i c h they are to be used. Each
n e t w o r k c i r c u i t controls the s i g n a l to the h i g h
and low frequency transducers i n such a w a y t h a t
smooth acoustic response is m a i n t a i n e d t h r o u g h
the f u l l audio spectrum. Thus, the effects of i n d i
v i d u a l speaker characteristics, impedance
tions, and the physical separation of the t w o sound
sources are all taken into account i n the complete
system design.
N a t u r a l l y , s u c h s o p h i s t i c a t e d e n g i n e e r i n g de
mands v e r y close tolerances i n p r o d u c t i o n i f a l l the
benefits of the design approach are to be realized.
O r d i n a r y networks, f o r example, often use electro
l y t i c capacitors w i t h tolerances of plus or m i n u s
2 0 % .
Response t h r o u g h the crossover r e g i o n is
ragged, and characteristics v a r y f r o m u n i t to u n i t .
A l l J B L n e t w o r k s , on the other hand, use only non-
i n d u c t i v e paper or m y l a r dielectric capacitors ( n o t
electrolytic u n i t s ) i n d i v i d u a l l y tested to meet J B L
tolerances. T h e special inductors used i n J B L net
w o r k s have extremely low i n s e r t i o n loss so t h a t
none o f t h e d r i v i n g p o w e r t o t h e l o u d s p e a k e r
system is wasted i n the n e t w o r k . Each i n d u c t o r
is c a l i b r a t e d on a sensitive electronic b r i d g e and
its value set precisely. T o meet J B L p r o d u c t i o n
tolerances, n e t w o r k components m u s t check o u t
w i t h i n plus or m i n u s 1 % o f the established design
value.
fluctua
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