The S4800 has an HF trim switch
mounted on the network panel
on the rear of the enclosure. The
HF Trim Switch
£
adjusts the
high-frequency level over the
range of approximately 1000Hz to
10kHz. The +1dB position gives the
highest HF output and measures
the most level. 0dB reduces the HF
level by 1dB, and the –1dB position
reduces the HF level by an addi-
tional 1dB.
Although the range of these control
settings is rather small, each of
them operate over a reasonably
wide frequency range and thus
have a noticeable effect on the
overall tonal balance of the system.
It is recommended that the system
first be played with the switch in
the middle position. This setting
gives the most uniform measure-
ments in a controlled environment.
Of course, we are interested in pro-
ducing the most pleasing sound in
your environment with your choice
of program material. It is, therefore,
recommended that the
HF Trim
Switch
£
be tested in its various
settings on a variety of program
material. Once you become familiar
with their individual character, you
should have no difficulty determin-
ing the setting that produces the
most pleasing, natural sound in
your room with your equipment.
¡
Mid-/High-Frequency Input
Terminals:
For bi-wire configura-
tions, connect the speaker wires
for the mid- and high-frequency
ranges to these terminals.
™
Shorting Straps:
Leave the
shorting straps in place only if
you are using the passive single-
wire connection option described
on page 13. Otherwise, remove
the straps to prevent possible
damage to the speakers or your
electronics.
£
HF Trim Switch:
This switch
allows you to adjust the output of
the high-frequency transducers to
compensate for the acoustics of
your room. The +1dB position
increases the output, the 0dB
position is a flat-level position,
and the –1dB position decreases
the output. Each position will
affect the tonal balance over
a wide frequency spectrum.
Experiment by placing the switch
in each position while listening
to familiar program material and
choose the position that suits
your room acoustics and listening
preferences. You may find after a
few months, once the transduc-
ers have settled in, that another
adjustment is necessary. This
is normal. The switch may be
adjusted using a flat-head screw-
driver.
¢
Low-Frequency Input
Terminals:
For bi-wire configura-
tions, connect the speaker wires
for the low-frequency range to
these terminals.
CHAPTER 6 – S4800 SWITCH OPERATIONS
11
CONTROLS AND
CONNECTIONS
¡
™
™
£
¢
Model S4800
HF - UHF
INPUT
HF - TRIM
LF
INPUT
JBL Incorporated, Northridge, California USA
+1dB
+0dB
–1dB
––
+
Figure 8. S4800 controls and connections.
S4800 OM 10/11/05 1:51 PM Page 11
