DOWNLOAD JBL K2S5800 (serv.man2) Service Manual ↓ Size: 225.64 KB | Pages: 20 in PDF or view online for FREE

CHAPTER 7 – PROJECT K2 S5800 SWITCH OPERATIONS

The K2 S5800 has two switches
mounted on the network panel 
on the rear of the enclosure. 
The switches are covered by 
an access plate which is easily
removed by unscrewing the two
mounting screws. See Figure 8.

The 

Switch ™ (center) should be left in
the Normal position except when
bi-amplification with an external
electronic crossover is to be
employed. The necessary cross-
over slopes for the K2 S5800 are
very specific and bi-amping the sys-
tem should only be done using fac-
tory-approved electronics.
The HF Trim Switch £ (right)
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 additional 1dB.

Although the range of these con-
trols 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 measurements 
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 

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 which produces the
most pleasing, natural sound in
your room with your equipment.

BI-A

MP

NOR

MAL/

BI-W

IRE

+1dB

0dB

-1dB

HIGH FREQUENCY TRIM

Figure 8. Access to control panel.

13

¡ Bias Battery: The bias battery
supplies constant DC bias to the
crossover capacitors, eliminating
crossover distortion at zero electric
potential. Replace the test battery
supplied with your system with a 
9-volt, 006P rectangular battery as
soon as possible. Thereafter,
although the speaker will function
without the battery, JBL recommends
that you replace the battery every
two years for best performance.
Access the battery by unscrewing the
cover. Make sure to observe proper
polarity when installing the replace-
ment battery.

™ Network Mode Switch:
This switch should be left in the
“Normal/Bi-Wire” position unless you
are connecting the speaker in a bi-
amp configuration using two power
amplifiers and an external electronic
crossover. Access the switch by
unscrewing the battery cover. The
switch may be adjusted using a flat-
head screwdriver.

£ HF Trim Switch: This switch
allows you to adjust the output of the
high-frequency transducers to com-
pensate 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 listen-
ing preferences. You may find that
after a few months, once the trans-
ducers have settled in, that another
adjustment is necessary. This is 
normal. Access the switch by
unscrewing the battery cover. The
switch may be adjusted using a 
flathead screwdriver.

¢ Mid/High-Frequency Input
Terminals: For bi-wire or bi-amp
configurations, connect the speaker
wires for the mid- and high-frequency
ranges to these terminals.

∞ Shorting Bars: Leave the short-
ing bars in place only if you are using
the passive single-wire connection
option described on page 15.
Otherwise, remove the bars to pre-
vent possible damage to the speakers
or your electronics.

§ Low-Frequency Input
Terminals: For bi-wire or bi-amp
configurations, connect the speaker
wires for the low-frequency range to
these terminals.

14

¡

™

£

¢

∞

§

Figure 9. K2 S5800 controls and connections.

15

The K2 S5800 is shipped with short-
ing bars installed between its low-
frequency and high-frequency 
terminals. Please see Figure 10. 
To prepare the K2 S5800 for bi-wire
or bi-amp operation, these bars
must be removed by completely
unscrewing each binding post,
removing the bars, and replacing
the binding posts. Wires can then
be connected to each set of termi-
nals (see Figures 10 and 12).

IMPORTANT: Turn all amplifiers off
before connecting or disconnect-
ing Project K2 S5800 loudspeakers.
Making connections while an
amplifier is operating could seri-
ously damage the loudspeaker
system and void the warranty. All
amplifiers must also be turned off
before connecting or disconnect-
ing cables at the amplifier or pre-
amplifier inputs.

All connections between the amp-
lifier(s) and the Project K2 S5800
loudspeaker system are made at
the terminals located on the back
of the enclosure (see Figures 10
through 13). The left-hand termi-
nals (black stripe) are negative,
and the right-hand terminals (red
stripe) are positive. These corre-
spond to the negative and positive
conductors in the speaker wire. 

Each speaker wire contains two
conductors, one of which will have
a stripe, color markings, or a ridge.

Assign one of the two conductors
as the negative conductor and the
other as the positive conductor.
Use these same designations for
all system wiring. Always connect
the conductors of the speaker wire
appropriately to the corresponding
negative and positive terminals on
all system components. This will
ensure that all components will
work together (“in phase”). Con-
necting the speakers out of phase
will not damage them but will
result in reduced low-frequency
output and impaired stereo effect.

Speaker wires may be fastened to
the terminals by several methods.
The most positive connection is
made by directly connecting clean,
bare connectors (exposed by strip-
ping the ends of the wire) to the
terminal posts.

For this type of connection, loosen
the knobs on the terminals and
insert the exposed (bare) ends of
each speaker wire into the hole
exposed on the terminal shaft 
( + to +, – to – ) (see Figure 13).
Refasten the knob on each termi-
nal so that a snug connection is
achieved. Do not apply excessive
force and do not overtighten. To
avoid a short circuit, trim off any
excess wire that is not in contact
with the binding post contact 
surfaces.

Project K2 S5800 terminals are 
also designed to accept spade or
banana-type connectors which are
fastened to the ends of the wires
and, in turn, are attached to the
terminal posts.  

As mentioned earlier, the Project
K2 S5800 speakers may be con-
nected to the amplifier(s) by one 
of three methods: passive, bi-wire
and bi-amp. Each method, des-
cribed below, has its own advan-
tages, and the Project K2 loud-

speaker system will deliver superb
performance with all methods.

Each speaker is shipped with
external shorting bars in place
(see Figure 10), connecting the
upper and lower terminal posts 
on the left and right sides. These
bars must remain in place for 
passive connections but must be
removed for all bi-wire and bi-amp 
connections.  

IMPORTANT: If the amplifiers are
connected to the Project K2 S5800
loudspeakers in the bi-wire or bi-
amp mode with the shorting bars
still on, the amplifier outputs will 
be shorted, which could result in
costly amplifier damage when
power is switched on.

The passive method requires one
amplifier and one set of wires.
Connections are made to the lower
terminals (one black, one red). Do
not remove the shorting bars.
Loosen the lower terminal caps.
Connect the positive conductor to
the right (red) terminal and the
negative conductor to the left
(black) terminal (see Figures 11
and 13). Refasten the terminal caps.

BI-AMP

NORMAL/
BI-WIRE

+1dB

0dB

-1dB

HIGH

 FRE

QUE

NCY

 TRIM

Figure 10. Removing
shorting bars.
(Bi-Wire or Bi-Amp
Connection Method)

Figure 11. Connecting speaker wires
using banana plugs.
(Passive Connection Method)

16

The bi-wire connection method 
requires one amplifier and two
sets of speaker wires. By removing
the shorting bars, connections may
be made to the individual network
sections using four conductors,
one for each of the four terminals
(see Figures 10, 12 and 13).

The optimal method of powering
the Project K2 system is with 
two amplifiers, one for the low-
frequency and one for the high-
frequency unit, and a crossover
network. Since each amplifier
drives only one speaker, this
method allows the user to select
amplifiers with the desired sonic
character for low and high fre-
quencies (see Figures 10, 12 
and 13).

Four identical amplifiers (or two
dual channel units) may be used,
although specialized low- and
high-frequency amplifiers offer
clear advantages. The Project K2
specialist dealer can recommend
the amplification that will best suit
individual needs.

In all cases, the left and right
amplifiers for each section must be
identical. Make sure that the input
sensitivity of the amplifier for each
section is equal, or that input level
controls are provided to maintain
the proper low-to-mid/high bal-
ance. If two identical stereo ampli-
fiers are used, one may be located
near each loudspeaker and drive
low- and high-frequency sections
through short wire runs.

NOTE: Input polarity must be the
same for both the low- and high-
frequency sections. Some ampli-
fiers invert polarity. If the polarity is
reversed to one section, a discon-
tinuity in response will be apparent
in the crossover region. If a prob-
lem is suspected, reverse the
polarity to either low- or high- 
frequency sections of both 
loudspeakers. Amplifier polarity
markings may not ensure correct
polarity connections.

The grilles on the Project K2 S5800
loudspeaker system have been
designed for maximum acoustical
transparency. For the most critical
listening, however, JBL suggests
removing the grilles. The grilles are
connected by four pins inserted
into four holes on the face of 
the cabinet.

To remove each grille, hold the
grille edges with your fingers and
gently pull the grille away. Do not
use any tools to pry the grille off;
this will damage the finish of the
cabinet. To replace the grille, posi-
tion the mounting pins over the
holes and gently press until the
grille meets the enclosure.

PROJECT K2 FINAL
CHECKLIST

• Connect and plug in all other 
system electronics.

• Check all connections. If bi-
amping or bi-wiring, make sure
both shorting bars are removed.

• Make sure the controls on the
crossover panel are correctly set.

The system is now ready for use.
The Project K2 S5800 speaker 
system is fully functional as soon
as it is set up. The amplifier power
should not exceed 300 watts (RMS).
There may be some subtle tonal
changes in bass output over the
first week to 10 days of operation.
These are caused as the move-
ment of the low-frequency drivers
becomes more fluid and the parts
settle in. This process is completely
normal with transducers of 
this caliber.

Figure 12. Connecting speaker wires
using banana plugs.
(Bi-Wire or Bi-Amp Connection Method)

Figure 13. Connecting speaker wires
using bare-wire method.