JBL 4411 Owners manual

PROFESSIONAL SERIES

FEATURES:

Smooth, accurate response from 45 Hz to 18 kHz
(+3 dB)

90 dB SPL, I W, 1 m (3.3 ft)
Components: 300 mm (12 in) low frequency

loudspeaker 130
25 mm (1 in) high frequency dome radiator

Oiled walnut enclosure

mm (5

in) midrange loudspeaker,

The Model 4411 is JBL’s most sophisticated 3-way
direct radiator monitor loudspeaker system. Apply­ing the knowledge gained in the design of the
4430 and 4435 constant coverage systems, JBL has
created a compact monitor especially well suited
to the demands of the digital age.

The three transducers of the 4411 are arranged in
a tight cluster to provide coherency of sound for
close-in monitoring, while assuring minimal off-axis

variation in the far field. Mirror-imaging improves
the stereo perspective. Continuously variable mid

and high frequency level controls, located on the
front panel, are calibrated for both a flat direct­field pressure response and a rising axial response

that produces a flatter power response. A large

port provides the proper low frequency loading.

With its high volume-velocity air movement capabil-

ities, the port also maintains the low frequency
dynamic range. The low frequency driver loading is
optimized for flat response when placed away from
room surfaces (approximating a 4 rr environment).
A rising bass characteristic can be chosen by

placing the monitors in proximity to a wall (2 7r
environment). An innovative crossover design

minimizes driver overlap, further assuring flattest
response at a wide variety of angles so that stereo

imaging remains stable over a wide horizontal angle.

Every aspect of the 4411 benefits from JBL’s
advanced technology. Each driver is the product of
extensive research and testing, and each has been
designed for optimum performance in the system.

In the tradition of the 4311, the new JBL 4411 sets

the standard for today’s compact studio monitors.

HIGH FREQUENCY
DOME RADIATOR

The new recording techniques place a premium
on high frequency accuracy and definition, and JBL
has designed the 044 high frequency dome radia­tor to meet these demands. In developing the 044,
JBL engineers used laser interferometry, analyzing
holograms (three-dimensional photographs) of
diaphragm motion to better understand the actual
stresses involved in reproducing musical wave­forms. The diaphragm of the 044 is fabricated from
linen, impregnated with a phenolic resin. JBL then
uses a sophisticated vapor-deposition process to
coat the phenolic with a microscopically thin layer
of aluminum. The combination makes the dia-

phragm rugged enough to withstand high-energy
high frequency peaks, yet light enough in weight to
respond instantly to transients. The copper voice

coil contributes to the high power handling and

drives the diaphragm over its full circumference for
smoother response. The 044 exhibits outstanding
linearity over its full operating range, at any input
level-there is almost no power compression.

MID FREQUENCY DRIVER

The latest version of a JBL design proven in
countless demanding applications, the LE5 mid­range driver has also benefitted from laser inter­ferometry. The newly designed cone markedly
lowers distortion, and the LE5 produces flat power
response to 6 kHz. Construction features include a

copper voice coil of flat wire, edge-wound to
increase the amount of conductor in the voice coil
gap and improve power handling and transient
response. Because there is more musical energy in
the midrange than at the frequency extremes, JBL
designed the LE5 with a substantial reserve of
dynamic range.

LOW FREQUENCY DRIVER

The 300
rates JBL’s unique Symmetrical Field Geometry
(SFG) magnetic structure, a design that reduces
second harmonic distortion levels to less than one­tenth of those typical of conventional designs. The

cone is of laminated construction to achieve the

desired combination of rigidity and light weight.
The coating, and exclusive JBL formulation, adds a
precise amount of mass and provides the opti­mum damping characteristics. The carefully
designed suspension elements, including a newly
engineered spider, reduce DC offsets and elimi­nate dynamic instabilities, reducing second har­monic distortion still furthel:’ The 75 mm (3 in)
diameter voice coil is formed of copper ribbon

wire, hand-wound on edge to place 24% more con-

ducive material in the voice coil gap. The 19 mm

(3% in) length of the coil allows longer excursions

for greater dynamic range.

mm

(12 in) low frequency driver incorpo-

FREQUENCY DMDING NETWORK

The sophisticated dividing network of the 4411
has a number of technological refinements that

improve the performance of the system in several
areas. A unique tuned double-bandpass circuit for
the midrange driver provides a steep, symmetrical
crossover to minimize out-of-band colorations and
reduce off-axis response variations. The steeper­than-average crossover slopes on all three drivers

improve power handling and minimize power­compression effects.

A major improvement occurs in transient wave­form resolution. JBL engineers applied a principle
typically found only in active high frequency elec­tronics: the use of polypropylene and polystyrene
bypass capacitors, wired in parallel with the net­work’s Mylar capacitors to reduce the hysteresis
effects on the signal. The network’s air-core and

iron-core inductors are carefully chosen for their
high current capacity and low DC characteristics.