LOUDSPEAKER SYSTEM
PROGRAM
SOURCE
ACTIVE
FREQUENCY
DIVIDING
NETWORK
2. Align the three holes in each crossover card with the
corresponding mounting pins on the main printed circuit
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
1
/ 4 " ) ,
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 connection
of the various inputs and outputs.
Mote: Operation
0 1
the 5231 or 5232
without
a crossover
card
will not damage the
unit-
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 JBL 4350
Studio Monitor, diagrammed above, is such a system. If a
pair of 4350's are to be used, a single 5232 can accommodate
both systems. Note that the passive, high level frequency
dividing network used in the 4350 already incorporates the
required attenuation capacitors to protect the midrange and
high frequency drivers.
Crossover Card Insertion
Prior to installing the 5231 or 5232, a crossover card must be
inserted in each channel as follows:
1. Place the 5231 or 5232 upside down on a soft surface,
remove the two Phillips-head screws from either side of
the case and lift the bottom cover from the chassis.
4
Table
1 .
Minimum Values
For Low Frequency
Attenuation Capacitors
T h e a b o v 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 a n y e l e c t r o n i c s p a r t s
s u p p l i e r . C a p a c i t o r b r e a k d o w n v o l t a g e s s h o u l d b e g r e a t e r t h a n 7 5 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 . If v o l t a g e a c r o s s t h e p r o t e c t e d d r i v e r
e x c e e d s t h e v o l t a g e at t h e o u t p u t o f t h e a m p l i f i e r at f r e q u e n c i e s j u s t
b e l o w c r o s s o v e r , a r e s i s t o r m u s t b e p l a c e d i n p a r a l l e l w i t h t h e
d r i v e r s . T h e r e s i s t o r s h o u l d h a v e a m i n i m u m v a l u e o f t w i c e t h e r a t e d
i m p e d a n c e o f t h e d r i v e r .
The crossover card is pressed on to mounting pins as shown. Note
the use of two hands to maintain proper alignment tor installation or
removal of the card.
Input and output terminals of the 5231 and 5232.
TWO
AMPLIFIERS
HF
LF
5231
LOW
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
HIGH
MID
F i g u r e 2 .
Combining Electronic And Passive Frequency
Dividing Networks
C r o s s o v e r F r e q u e n c y
D r i v e r I m p e d a q e ® ^ ^
4 o h m s
cl
£>mf$ 16
o h m s
250
H z t o
500
H z _ ^ * »
A b o v e
500JHgJf>^r1z
. '20O0
/ i f
100.0
/xf
50.0
/ i f
100.0
/ i f
50.0
/ i f
25.0
/ i f
1 0 . 0
/ i f
5 . 0
/ i f
2.5
/ i f
M o u n t i n g
The 5231 or 5232 can be mounted in a single EIA standard
rack space without additional bracing or ventilation.
Air
external connections are made on the rear panel. Mounting
hardware is supplied with each unit.
