JBL 3678.v1
User Manual: JBL JBL - Manuals+
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3678
Cinema
Loudspeaker System
Application:
Small room, cinema sound systems.
Key Features:
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Frequency Range: 30 Hz to 20 kHz
(–10 dB)
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Sensitivity, 98 dB
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Power Capacity: 300 watts passive,
50 (HF)/600 (LF) watts bi-amp
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Low frequency transducer: One
380 mm (15 in.) low frequency
driver
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High frequency transducer: 25 mm
(1 in.) horn throat diameter,
44 mm (1.75 in.) pure titanium
diaphragm compression driver
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Flat power response 100° X 100°
Bi-Radial®horn
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Operable in bi-amp or passive
mode
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Includes adjustable bracket for
horn aiming
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Shallow profile cabinet minimizes
behind-screen space requirements
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THX®-approved for THX system
installations
The JBL 3678 cinema loudspeaker
system provides natural sound quality
for music and dialog in small cinema
applications. It can be used in either
a passive mode, using its built-in
network, or in a bi-amplified system.
Enclosure design is extremely shallow
in depth (292 mm; 11.5 inches), to
minimize the space required behind
the screen.
The high-frequency section consists
of the JBL 2426 pure titanium
compression driver and 2342
Bi-Radial horn. The titanium
diaphragm of the 2426 ensures the
natural sound and reliability
mandatory in today’s motion picture
theatres. The 2342 horn provides
smooth, even coverage throughout
the auditorium.
The low frequency section uses a
single JBL 2226H driver. This 600
watt driver features JBL-patented Symmetrical Field Geometry (SFG) and
Vented Gap Cooling™ technology for high power handling with minimal
power compression.
The newly-designed passive crossover network is optimized to provide
seamless transition between driver components, for clear, articulate dialog,
and high fidelity music reproduction. Operation in a bi-amplified system is
easily achieved by simple re-configuration of the jumper connectors at the
network/connector panel.
In bi-amplified mode, the 3678 is THX-approved for THX certified theatres
no larger than 1,274 m3(45,000 ft3) and screen-to-last row distances no
greater than 12.2 m (40 ft.).
System Specifications:
System:
Frequency range (-10 dB): 30 Hz to 20 kHz
Frequency response (± 3 dB): 45 Hz to 12 kHz
Power capacity1(passive): 300 W
Power capacity (bi-amp): HF: 50 W
LF: 600 W
Sensitivity: 98 dB
Nominal impedance: 8 ohms
Crossover Frequency: 1 kHz
Nominal coverage: 90° horizontal, 90° vertical
Half-space reference efficiency: 3.3%
Maximum acoustic power output
(sine wave input) 8 acoustic watts
System Polarity: Positive voltage to RED produces forward cone motion
Input connectors: Barrier strip screw terminals
Net system weight: 41 kg (90 lbs)
Shipping weight: 44 kg (98 lbs)
Dimensions (H x W x D): 406 (w/horn) x 651 x 292 mm
40.125 (/horn) x 25.625 x 11.5 inches
1Rating based on test signal of continuous pink noise, per IEC spectrum for two hours duration.
JBL continually engages in research related to product improvement. Some 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 published description, but will always equal or
exceed the original design specifications unless otherwise stated.
Professional Series
75925_JBL_3678 7/24/08 8:12 AM Page 1
䉴3678 Cinema Loudspeaker System
SS 3678
980-00018-00
CRP 1M
08/08
JBL Professional
8500 Balboa Boulevard, P.O. Box 2200
Northridge, California 91329 U.S.A.
© Copyright 2008 JBL Professional
A Harman International Company
75925_JBL_3678 7/24/08 8:12 AM Page 2
