JBL 4560, 4530 Low Frequency Enclosures2[1]

JBL low frequency enclosures are designed for sound repro­duction or reinforcement in theaters, arenas, discotheques,

L,’ or other similar applications where high sound power output

and smooth low frequency response are requrred All are
ruggedly constructed of dense, high qualrty stock and braced
to elrmrnate resonances The baffle panels accept 380 mm
(15 In) dnvers and are fitted with X-20 threaded T-nuts to

facilitate loudspeaker mounting. MA15 loudspeaker mounting

kits are supplied with all front mounting enclosures.

Rear Loading Horns

JBL rear loading horns perform best

in relatively short

throw
applications (75 feet or less) where strong response to the
lowest musical frequencies is more important than high
directivity or ultimate efficiency. Rear loading horns utilize the
back waves of the loudspeaker to energize a long, compactly

folded hornThese back wavesarecoupled to the unrestricted

radiation of the loudspeaker’s front waves. The acoustic

loading effect of the horn reduces nonlinear distortion and
boosts low frequency efficiency dramatically. Above 150 Hz,
the enclosure design allows the loudspeaker to effectively

uncouple from the horn and operate as a simple direct
radiator, with its back wave attenuated by the horn.The upper

frequency limit is essentially that of the loudspeaker used
(a JBL 2205 or El40 is recommended). Phase inversion
of the rear waves, due to the propagation time through
the horn length, further augments response in the lowest
operating ranges.

NOTE: Below the lowest usable frequency given for

each model, the excursion limiting load presented by
the horn is reduced.To avoid excessive cone excursion
and possible damage, power input at these very low
frequencies should be restricted.

Model 4520 Dual Driver Horn

Thirteen-foot folded horn provides maximum loading to 42 Hz,
usable response to 30 Hz. Net weight, less drivers, 98 kg
(215 lb). 1276 mm x908 mm x756 mm deep (50% in x

35% inx29% in deep).

Frequency response curve of the 4520 taken with two 2205

speakers installed Measured response of a typical production unit,
lncludlng all peaks and dips does not deviate more than 2 dB from
the above curve

loud

Model 4530 Single Driver Horn

Seven-foot folded horn provides maximum loading to 50 Hz
wrth usable response to 40 Hz Net werght, less driver, 54 kg
(120 lb) 1213 mm x 603 mm x 603 mm deep (47% in x

23% tn x 23% In deep)

Frequency response curve of the 4530 taken with one 2205 loud
speaker installed Measured response of a typlcal productlon umt,
lncludlng all peaks and dips, does not deviate more than 2 dB from
the above curve

Front Loading Horns

JBL front loading horns furnish the best pattern control and
highest conversion efficiency obtainable from low frequency
cone transducers. They are ideal for use in large halls, out­door environments, and other similar applications in which
long throw and maximum

efficiency

are primeconsiderations

Model 4560A Single Driver Horn

Directional horn for a single 380 mm (15 in) driver. Horn and
vented rear reflex chamber give usable response to 45 Hz
with maximum loading above 200 Hz. Dispersion pattern is
90 degrees horizontal x 60 degrees vertical at 800 Hz. Net
weight, less driver, is 41 kg (91 lb). 914 mm x762 mm x
606 mm deep (36 in x 30 in x 23% in deep).

Within their optimum operating frequency range, the front
loading horns add 6 dB to the on-axis sensitivity of the
loudspeaker. This allows a reduction in the number of

L-

loudspeakers needed and the amplifier power required
compared to direct radiating systems of equal capability.
Below the cutoff frequency (determined by horn size and
geometry), the increased directivity and efficiency of horn
loading are progressively lost. Usable response, however,
is maintained to an octave or more below cutoff due to the
action of the vented rear chamber.

The front loadrng horns may be used wrth the JBL 2220,2205,
E140, or El45 The lower resonances and longer excursron
capabrlrtres of the 2205, E140, and El45 enable these loud­speakers to provide somewhat better deep bass response
compared to the 2220 at the expense of some midrange
sensitivity There

IS,

however, the possibrlity of their cones
stnking the horn throat on extreme outward excurstons
Therefore, power input at very low frequencies should be
somewhat more conservative than normally specified for
these loudspeakers

Frequency response curve of the 4560A taken with one El45 loud­speaker installed Measured response of a typical productlon unit
Including all peaks and drps does not deviate more than 2 dB from
the above curve

3

Model 4550A Dual Driver Horn

Directional horn for two 380 mm (15 in) drivers. Loads
effectively above 100 Hz, with usable response to 40 Hz.
Dispersion pattern at 800 Hz is 75 degrees horizontal x
30 degrees vertical. Net weight, less drivers, is 88 kg
(195 lb). 914 mm x 1524 mm x825 mm deep (36 in x
60 inx32K in deep).

Frequency response curve of the 4550A taken with two El45 loud­speakers Installed Measured response of a typlcal production unit
lncludtng all peaks and dips, does not deviate more than 2 dB from
the above curve

4550A

Direct Radiating Enclosures

Model 4508 Bass Reflex Dual Driver

The 4508 is a slim-profile, vented enclosure that offers
outstanding low frequency reproduction in a
package. Frequency response is uniform to 45 Hz with
usable response to 35 Hz. Net weight, less drivers, is 49 kg
(108% lb). 1060 mm x 667 mm x464 mm deep (41% in x

26% inxl8X in deep).

Frequency response curve of the 4508 taken with two El45 loud­speakers installed. Measured response
including all peaks and dips, does not deviate more than 2 dB
from the above curve.

of

a

very compact

typical production unit,

Models EN3, EN5. and EN8
Multipurpose Enclosures

JBL multrpurpose enclosures are designed to allow con­venrent construction of custom low frequency and full

range sound systems Specrfrc component and porting
recommendatrons are listed In Table 1 Each enclosure

IS

constructed from rugged 19 mm (% in) stock and
features hand-fitted, heat-cured joints Enclosure veneers
are of furniture-qualrty black walnut and have a hand-

rubbed, oiled flnrsh. The enclosures are available in 85,

140, and 225 lrtre sizes (3, 5, and 8

cubic feet)

Frequency response curve of the EN3 taken wrth one 2203 loud-

speaker Installed Measured response of a typrcal productron

unit rncludrng all peaks and dips, does not deviate more
than 2 dB from the above curve

Frequency response curve of the EN5 taken with one 2205 loud-

speaker installed. Measured response of a typical production unit,

including all peaks and dips, does not deviate more than 2 dB from

the above curve.

Table 1.

Recommended Components

(85 litre)

EN3

(140 like)

EN5

EN8 (225 litre)

1. Use 4” duct in port.

2. Use 2” duct-cover 4” duct.

Low Frequency

2202 or 2203’

2205,2220,
or E140f 22313

223V

El30

(Subwoofer)

3 Use 4” duct-cover 2” duct.

4. Mount 4” duct in both holes

High Frequency

2307 2311
horns with 7308 IPW 33% 11-x 19% I” x 12’%2 I” deep

2307, 2311,
horns with 2308 lens

N/A

Crossover Frequencies

or 2312

or 2312

Frequency response curve of the EN8 taken with one 2231 loud­speaker Installed Measured response of a typlcal productlon unit,
lncludlng all peaks and dips, does not deviate more than 2 dB from
the above curve

Ultra-High Frequency

2402 2405.

2402.2405.

or 2403

or 2403

N/A

Dimensions

x489 mm x 318

845 mm

x 521 mm x464

883 mm
34% I” x 20% I” * 18X I” deep

mm deep

mm deep

1060 mm x 667 mm x464 mm deep
41%inx26%1nx18% ~ndeep

The recommended crossover frequency of all JBL low
frequency horns IS 800 Hz or lower The exact crossover
point chosen will depend principally on the performance
characteristics of the high frequency components used In the
system

JBL manufactures a complete line of high frequency trans­ducers as well as dividing networks, power ampllflers, and
other accessories designed to complement the performance
of the equipment described herein Contact JBL or your
JBL Professional Products dealer for complete details

JBL continually engages in research related to product improvement

New materials, production methods, and design refinements are
introduced into existing products without notice as a routine expres­sion of that philosophy. For this reason, any current JBL product
may differ in some respect from its publrshed description but is
always warranted to equal or exceed the original design specifications
unless otherwise stated.

Professional Division

James B. Lansing Sound, Inc., 8500 Balboa Boulevard, Northridge, California 91329

U.S.A