L O U D S P E A K E R S Y S T E M
P R O G R A M
S O U R C E
T W O
A M P L I F I E R S
A C T I V E
F R E Q U E N C Y
D I V I D I N G
N E T W O R K
It is possible to construct a system using an electronic low
frequency transition and a conventional passive network for
the midrange or high frequency crossover. The J B L 4350
Studio Monitor, diagrammed above, is such a system. If a
pair of 4350's are to be used, a single 5234 can a c c o m m o -
date both systems. Note that the passive, high level frequency
dividing networks used in all J B L studio monitors designed
for bi-amplification already incorporate the required atten-
uation capacitors to protect the midrange and high frequency
drivers.
Crossover Card Insertion
Prior to installing the 5233 or 5234, a crossover card must
be inserted in each channel as follows:
1. Place the 5233 or 5234 upside d o w n on a soft surface,
remove the two Phillips-head screws f r o m either side of the
case and lift the bottom cover from the chassis.
2. Align the three holes in each crossover card with the cor-
responding mounting pins on the main printed circuit
The crossover card is pressed on to mounting pins as shown. Note
the use of two hands to maintain proper alignment for installation or
removal of the card.
board. The components on the card should face toward
the chassis with the frequency designation label oriented
toward the front panel.
3. As the card is gently pressed against the mounting pin
stops [approximately % in, 6 m m ] , electrical connection will
be made between the card connector and six pins on the
printed circuit board.
4. Replace the bottom cover and secure it with the four
screws. The unit is now ready for mounting and connec-
tion of the various inputs and outputs.
Note: Operation of the 5233 or 5234 without a crossover
card will not damage the unit.
T a b l e 1. M a x i m u m V a l u e s
F o r L o w F r e q u e n c y
A t t e n u a t i o n C a p a c i t o r s
Crossover
Driver Impedance
Frequency
4 H 8 0 16
n
250 Hz to 500 Hz
150
,xF
80
ju
F
40
^F
500 Hz to 5 kHz
80
^F
40
^F
20
5 kHz and above
8
M
F
5
/uF
2 jiF
C a p a c i t o r w o r k i n g v o l t a g e s s h o u l d b e at least 5 0 V. D o n o t u s e
p o l a r i z e d e l e c t r o l y t i c c a p a c i t o r s ; p a p e r o r M y l a r c a p a c i t o r s a r e
a c c e p t a b l e . A 5 0 W r e s i s t o r h a v i n g a v a l u e o f t w o t o t h r e e t i m e s t h e
r a t e d i m p e d a n c e of t h e d r i v e r s h o u l d a l s o b e c o n n e c t e d a c r o s s t h e
d r i v e r t e r m i n a l s . T h e s e c a p a c i t o r s a r e a v a i l a b l e f r o m e l e c t r o n i c
p a r t s s u p p l i e r s . A l i s t i n g of c a p a c i t o r s t h a t m a y b e o b t a i n e d f r o m
J B L a n d t h e f o r m u l a f o r d e t e r m i n i n g c a p a c i t o r v a l u e s a r e p r o v i d e d
in T a b l e 4 , l o c a t e d in t h e a p p e n d i x . N o t e : B e l o w t h e c u t o f f f r e q u e n c y
o f t h e c a p a c i t o r , t h e p o w e r a m p l i f i e r will b e u n t e r m i n a t e d . If t h e
p o w e r a m p l i f i e r h a s a n o u t p u t t r a n s f o r m e r , a 2 0 W r e s i s t o r e q u a l t o
t e n t i m e s t h e d r i v e r i m p e d a n c e s h o u l d b e i n s t a l l e d a c r o s s t h e
a m p l i f i e r o u t p u t t e r m i n a l s .
Mounting
The 5233 or 5234 can be mounted in a single EIA standard
rack space without additional bracing or ventilation. All
external connections are made on the rear panel. Mounting
hardware is supplied with each unit.
3
5 2 3 3
P A S S I V E F R E Q U E N C Y
D I V I D I N G N E T W O R K
U L T R A - H I G H
H I G H
M I D
F i g u r e 2 .
Combining Electronic And Passive Frequency
Dividing Networks
Input and output terminals of the 5233 and 5234.
