Jbl 2446 h brochure

Page 1

UBL

Professional Series

Key Features:

)100 watts continuous program
at 500 Hz

>150 watts continuous program at
1 kHz and higher

V Coherent Wave phasing plug design
for increased highnfrequency output

>100 mm (4 in) pure titanium dia7
phragm with radialirib topology
and patented threeidimensional
diamond pattern suspension

} 100 mm (4 in) edgewound
aluminum voice coil

D 4) mm (2 in) throat exit diameter

The model 2446H/J is a professional
quality highnfrequency compression
driver that incorporates JBLs newly
developed Coherent \Cave phasing
plug as well as a pure titanium dian
phragm with radial ribs and patented
threendimensional diamond pattern
suspension.

The Coherent \Wave phasing plug
assembly consists of four diencast
annular aperture structures of con,
stant path length to provide miphase
combining of diaphragm output at the
drivers exit. This optimized configun
ration allows coherent summation of
acoustical power up to much higher
frequencies than afforded by earlier
designs.

The diaphragm design includes
jBLs exclusive threendimensional
diamond pattern surroundl which
reduces membrane stresses in the
diaphragm support structure and
extends diaphragm life. The depth of
the diamond pattern is closely con,
trolled during the manufacturing
process to provide predictable fre7
quencies for the 2nd and 3rd normal
resonance modes and for the basic
suspension resonance mode. The
diaphragm also incorporates a series
of embossed radial reinforcing ribs
that increase diaphragm stiffness. This
diaphragm, when combined with
the Coherent \Wave phasing plug,
increases the 2446H/Js output in
the 5 kHz to 21) kHz range.

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Specifications:

Ihroat Diameter:

49 mm «2 in)

244611 8 ohms
2446] 16 ohms

0 ohms (11). 12 ohms (1) @ klla

Nominal Impedance:

Minimum Impedance:

5
Dc Re 4.5 ohms (11), 85 ohms (J) t 10% @ 25

Power 100 \i' continuous program above 300 112

150 \X' continuous program above 1 kHz

Sensitivity: 111 dB SPL, 1 \i @ 1 m Unraxis on horn2

118 dB SPL, 1 m\{' on planCrwavc tube3

Nominal Efficiency: 30% (500 117 to 2.5 kllz)

Frequtncy Range: 500 112 to 20 kllz

Recommended Crossover: 500 112 or higher, 12 dB/oetave minimum

Diaphragm: 0.05 mm (0.002 in) pure titanium

Voice Coil D1ameter: 100 mm (4 in)

Voice Co1l Material: Edvewound aluminum ribbon

Flux Density: 1.9 T (19000 gauss)

Bl Factor: 12." (11) N/A
18 (1) N/A

Positne voltage to black terminal gives diaphragm monon toward the phasmg plug

Dimensions: 255 mm (91/. in) tiininctti
151 mm (51mm) depth

Mountinv: Four 9/4720 threaded holes, 90° apart on 101.6 mm (4 in) diameter

Net \C'eight: 13.8 kg (30% lb)

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Page 2

D 2446H/J Compression Driver

High temperature Voice coil former materials and adhes
sives enable the 2446H/J to handle extremely high power
levels over extended periods of time The voice coils
themselves are identical to previous JBL models, so that
impedance and network matching will be the same. After
manufacture, the frequency response of each driver is
tested for conformity to JBLS rigid performance standards

The model 2446H/J is ruggedly constructed to withstand
the rigors of both fixed and transportable commercial
applications All cast parts and machined tolerances are
held to the same levels traditionally associated with JBL
designs. The JBL manufacturing process also permits the
use of rim centered rather than pin mounted diaphragms,
for instant interchangeability and ease of field service.

Architectural Specifications:

The compression driver shall consist of a ferrite magnet structure
\Vith all magnetic assembly parts machined from east or extruded
billet stock. The phasing plug shall be assembled of concentric horns
of equal path length to eliminate case cancellations, and it shall be
coupled to a tapered throat. The diaphragm shall be 0.05 mm (0.002
in) pure titanium pneuniari'eally drawn to shape and embossed with
radial reinforcing ribs to increase stiffness. High frequency response
shall be controlled through the use of a threesdimensional suspension
structure. The voice coil shall be edgewound aluminum ribbon of not
less than 100 mm (4 in) diameter, operating in a magnetic field of not
less than 1.9 tesla (19,000 gauss).

Performance specifications for a typical production unit shall he as
follows: Measured sensitivity with a 1 mW input on a 25 mm (1 in)
terminated tube, aveiaged from 500 Hz to 2.5 kHz, shall be at least 118
dB SPL. Measured sensitivity with a 1 \\" input at a 1 m distance on axis
from the mouth of a horn with a Q of 6.3 averaged in the 2 kHz octave
band shall be at least 111 dB SPL. As an indication of electromechanical
conversion efficiency, the B1 factor shall be at least 18 newtons per
ampere. Frequency response, measured on a terminated tube, shall
be flat within it 1 dB from 500 Hz to 3.3 kHz, with (i dB/octave rollsoff
above that point. Nominal impedance shall be 8 [16] ohms and power
capacity shall he at least 100 watts normal speech or music program
material.

The compression driver shall be the jBL Model 244611[]]. Other
drivers will be considered for equivalency provided that submitted
data from a recognized independent test laboratory verify that the
above performance specifications are met.

isi
(575/32)

i é'i
Im.B on I n
56
(275nm _

49 22:
u-is/isi ' ' i841)

IlA-Zn VB
4 HOLES (1/32) -' l

More: DIMENSIONS IN i J
ARE lN INCHES.

Response on JBL 2380A FlatsFront BisRadiallHorn

«20

1m

sPL as (re 20 uFa)
8

Frequency in H!

Frequency response of the 2446] coupled to a _]BL 2380A FlateFront
BisRadial Horn, measured onsaxis at a distance of 1 meter with a
lswatt (4.0 V rms) input in a reflectionsfree environment, with
impedance vs. frequency curve. A horn with a pure exponential flare,
such as typical radial horn designs, will exhibit greater highefrequency
output onsaxis at the expense of lose angmlar coverage.

Response on Plane Wave Terminated Tube

m mm
150

I40
5
i
a i.
g m g
54 .
e E
in e
120 §
. - , l
100 MD 10000 20000
Frequency ln H1

Frequency response and impedance modulus of Model 2446]

coupled to as 49 mm (2 in) tube, with sensitivity referred to a 25 mm
(1 in) tube. This is the power response of the transducer, and is the
frequency response that will be obtained on a true fullsrange constant
direeri'viry horn design, such as jBLs 2360 series of constant coverage
BisRadial horns.

JBL Professional
8500 Balboa Boulevard, PiOi Box 2200
Northridge, California 91329 U.S.l\i $4491?

H \ iirmAn international (.(lmpiinl io/w,