JBL 1000 ARRAY Brochure & Specs page 19

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Dimensions Weight
(H x W x D)
1181mm x 394mm x 483mm 52kg/115 lb
46-1/2" x 15-1/2" x 19"
1105mm x 311mm x 432mm 32kg/70 lb
43-1/2" x 12-1/4" x 17"
743mm x 273mm x 356mm 18kg/40 lb
29-1/4" x 10-3/4" x 14"
311mm x 730mm x 279mm 21kg/46 lb
12-1/4" x 28-3/4" x 11"
584mm x 495mm x 483mm 57kg/125 lb
23" x 19-1/2" x 19"
533mm (21") Deep with grille
Since many of the best sounding direct-radiator systems have minimal baffle areas, particularly around the
mid- and high-frequency drivers, it was reasonable to conclude that minimizing baffle area and diffraction
around a horn might improve imaging and frequency response. This is the major design concept behind the
Array Series. The horn has been oriented to minimize width, and to position the diffraction slot within the horn
in the vertical plane. Next, the top of the LF enclosure has been cut away so the horn is nearly freestanding.
The horn enclosure is minimal and heavily windswept, again to minimize diffraction. The final major feature is
the capability of the horn to be moved forward or back without creating baffle discontinuities. This allows the horn
HF and LF driver to be lined up in the depth direction to achieve the best time behavior over a large frequency
range. This also allows the drivers to be "in polarity" in addition to "in phase" at the crossover point. The sum
total of these main features is a loudspeaker system with the speed and dynamics of a compression-driver
system, but with the smoothness and imaging of the best direct-radiator and panel systems.
The industrial design of the system was quite a challenge. Having established a number of important criteria
regarding the relative location and packaging of each transducer, it became necessary to consider a less
conventional design. The LF enclosure needed to be heavy, solid and vibration free. In addition, it needed to
allow the horn module to sit as low as possible to reduce the center-to-center distance between the LF
and HF drivers. The horn itself is molded from a high-density resin material using an extremely thick wall
section. This makes the horn heavy and acoustically inert. The horn is mounted directly to the top of the
LF enclosure in a rigid manner. Experiments during development revealed that decoupling the horn from
the LF enclosure adversely affected the three-dimensional image. The horn enclosure is molded in structural
foam, again with a thick wall section.
The woofer section and high-frequency horn section are acoustically joined by a sophisticated crossover
network. The low-frequency and high-frequency sections of the network are located on separate circuit
boards mounted in different places within the enclosure to minimize interference between the different filter
sections of the crossover. The acoustic-crossover slopes are all 4th order (24dB/octave), and the horn-module
location has been optimized in the depth location for minimum time error over a large frequency range.
The 880 Array (center channel) has been designed to have the same timbral and phase behavior as the tower
systems. This is essential in a multichannel setup to ensure proper decoding of the source material, which
was most probably mixed using identical speakers at all positions. Five (or seven) identical speakers are the
best way to re-create the sound space that the authors of the recording intended. Unfortunately, the size and
cost of five front speakers are often problematic. A large center speaker is also a major problem for anything
but a perforated front-projection screen. Designing a compact yet powerful dedicated center speaker is quite
a challenge, particularly when the other models in the lineup perform so well. Obviously, using identical or
similar transducers is very important. It's also necessary to match frequency response, directivity response,
distortion characteristics and phase response. In the case of the Array Series, all four models have been
optimized to work with each other in any combination of front, center and rear.
We feel the new Array Series exemplifies the best of JBL's tradition and heritage, while clearly taking advantage
of our ultramodern research and development facility. We hope you'll enjoy every minute of listening.
Regards,
Greg Timbers
JBL Chief Systems Engineer
A Message From Greg Timbers,
JBL's Chief Systems Engineer
I've long been a fan of compression-driver systems. They have a speed and
effortlessness unmatched by direct-radiator systems. Current hardware is
very low in distortion, has smooth frequency response and can be designed
to have very smooth, consistent directivity patterns. However, I've always felt
that, as good as the three-dimensional image provided by these systems is,
it could be even better.
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