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The following sections describe the
primary features and components
of the S4800 loudspeaker system.

The enclosure of the S4800 is
specially designed to transfer
unwanted mechanical energy away
from any acoustically active
surfaces, virtually eliminating
coloration.

The massive enclosure, along with
its specially designed brass
modular feet, couples directly to
the floor, and the system literally
becomes a structural part of its
environment. Any vibration is
transmitted harmlessly down the
channel provided by the ring/disc
axes and into the floor. The
SonoGlass combination horn
maintains a smooth energy
transmission path.

The S4800 transducer/enclosure
arrangement represents the best
possible balance of the various
tuning options and avoids the mid-
bass response buildup found in
other vented systems. Response
works with, rather than against,the
effects of “room loading.”

The unique design of the system is
the platform for its equally unique
acoustical attributes.

Thanks to the combination horn,
both the UHF (ultrahigh-frequency)
and HF (high-frequency) drivers are
located at the ear level of the
listener. 

See Figure 2.

The large 3-inch HF transducer
allows the 15-inch woofer to be
crossed over at a frequency low
enough to eliminate any audible
effects of its exact location and
proximity. 

Full image coherency is main-
tained, resulting in an acoustically
stable pinpointed stereo image. All
the sound seems to come from the

combination horn. Music imaging is
more realistic since the sound
appears to emanate from one point
and not from multiple points at
different times. 

The S4800 is a constant-angle
system without regard to
frequency. Careful horn design
enables the loudspeaker to strictly
adhere to a 100° horizontal/60°
vertical coverage pattern. This
controlled coverage arrangement
precisely defines the optimum
listening area and minimizes room
effects. At the same time, it
provides a generous “sweet spot”
for more comfortable critical
listening sessions.

See Figure 3.

In order to achieve the lowest
possible distortion and
compression along with the high
linear excursion necessary, the
1500FE is equipped with a ferrite
magnet. As with earlier JBL low-
frequency drivers, it utilizes forced-
air cooling. The entire magnetic
structure is attached to a die-cast
aluminum-alloy frame. 

Figure 2. Height of S4800 speaker system in relation to listener.

Figure 3. 

Cutaway view of 1500FE 

low-frequency transducer.

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This provides accurate, rigid
support for the motor and cone
mounting points, as well as
doubling as a massive heatsink by
providing a huge surface area for
heat dissipation.

The 1500FE has a central cooling
duct that effectively cools the voice
coil and reduces the likelihood of
hot spots. By reducing the
operating temperature of the voice
coil, power compression is
significantly reduced, which
enables the low-frequency driver to
operate in a more linear fashion
over a wider sound pressure level
(SPL) range. 

The voice coil itself is constructed
from edge-wound aluminum wire
on a massive 4-inch-diameter
fiberglass former. This
configuration provides for further
cooling ability in conjunction with
the motor design.

The Aquaplas-coated, Kevlar-
composite cone, along with the 
EPDM rubber surround, provides
excellent damping and transient
response characteristics.

See Figure 4.

The 435AL neodymium high-
frequency compression driver is
based on the professional JBL 2430
device. It incorporates a rare-earth
neodymium magnet structure,
designed by extensive computer
modeling, including finite element
analysis, which combines the
attributes of efficiency, strength,
low mass and compact size. This
motor structure is coupled with 
a 3-inch aluminum diaphragm.
Aluminum provides improved low-
distortion characteristics and flat
frequency response. 

High-temperature materials and
adhesives allow the driver to
handle extremely high power levels
over extended periods of time. The
SonoGlass horn is acoustically inert
and precision-molded to exacting
tolerances. 

Figure 4. Cutaway view of 435AL high-frequency transducer.

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See Figure 5.

The 045Ti utilizes the same
principles as the 435AL, in a smaller
footprint so that a frequency
response up to 40kHz can be
achieved.

Each loudspeaker unit has two
internal dividing networks, one for
the LF transducers and one for the
combined HF and UHF transducers.

The low-frequency section
interfaces with the external main
control panel for input connections
and switch functions. They also
employ massive air core inductors
for the best possible sonic
characteristics and lowest possible
coloration.

All internal connections use
proprietary Monster Cable,

®

and all

critical connections are gold-plated
for long life. Capacitors are
ultrahigh-grade polypropylene for
extremely low loss. All switches
and components are of the highest
quality for long life and reduced
distortion of all types.

The network also facilitates bi-
wiring as necessary, using shorting
straps where only a single-wire
connection is desired.

The HF trim control allows fine-
tuning of the high-frequency output
level to the acoustics of the
listening space as well as to the 
listener’s liking.

The all-metal, gold-plated, 5-way
binding-post input connectors 
provide for bi-wiring, which is
explained in detail later in this
guide.

The enclosure design of the S4800
minimizes coloration by
dramatically reducing panel
radiation. It is constructed from 
1-inch (25mm)-thick MDF.

The enclosure’s unusual thickness,
along with the SonoGlass horn
assembly, add up to the lowest-
vibration, most acoustically inert
loudspeaker enclosure presently
possible to construct. Enclosures
are finished with a high-gloss
polyurethane lacquer.

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Figure 5. Cutaway view of 045Ti ultrahigh-frequency transducer.

All components of the S4800
system have been very carefully
packed for maximum protection
against damage. 

As with any superior audio product,
it is advisable to keep the original
packing materials in case it is
necessary to transport the S4800
system.

Because of the bulk and weight of
this loudspeaker, at least two
people are required to unpack it in
the following manner: Open the
front as well as the top of the
carton. Slowly and carefully “walk”
the loudspeaker in its Styrofoam

™

end pads out of the carton. Two

people may then lift the system out
of the end pads.

The four spiked feet are pre-
installed in the bottom of the S4800
in four locations. Four metal
coasters are packed in the end
pads. These are to be placed
between the feet and the floor for
further protection of floor
coverings. See Figure 6.

Figure 6. Inserting
spiked feet.

Speaker wire and interconnecting
cables are critical components in
any audio system. With a system
such as the S4800, they assume a
new level of importance.

S4800 loudspeakers are internally
wired with high-quality copper
Monster Cable, specially designed
for JBL. The same care that was
given to the selection of internal
system wiring should be afforded to
the selection and application of the
cables that will connect S4800
loudspeakers to other system
components.

It is advisable to use high-quality
wire, such as Monster Cable, and
to select the highest-grade wire
available from the manufacturer.
Many manufacturers produce
audiophile cables worth
considering for the S4800. As with
all electronics and associated
components, however, every
manufacturer offers products of
varying quality to suit a range of
budgets and applications.

We recommend using an
audiophile-quality speaker wire of
not less than 16 gauge for
connections up to 15 feet (5 meters)
as a minimum requirement. If your
connections will be longer, heavier-
gauge wire is recommended. JBL
specialist dealers have the
experience and knowledge to
recommend suitable speaker wire
to best complement a particular
system.

The amount of speaker wire
required will depend on the
distance between the loudspeakers
and amplifier(s), how many
amplifiers will be used, and the
method you select for connecting
the amplifier and loudspeakers
(passive or bi-wire; see Chapter 6).
For maximum signal purity, it is
advisable to locate the amplifier(s)
as close as possible to the
loudspeakers, even if this means
that a longer distance will be
needed between the amplifier(s)
and preamplifier.

Both the left and right speaker/
amplifier connections should be the
same length. If the distance
between one speaker and the
amplifier(s) is greater than the
other speaker and amplifier(s), use
the longer length for both
connections.

For bi-wire connections, the same
type of wires may be used for both
the low-frequency and high-
frequency sections to reduce wire
effects (resistance, inductance,
etc.) and to avoid intermodulation
of low and high frequencies in the
wires. Specialized wires for low-
frequency and high-frequency
sections may yield excellent
results. Whatever wires are used,
be sure that the low-frequency
wires are as short as possible, and
the left and right wires for each
section are the same length.

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