JBL VT4887A User manual

VT4887A
Specifications:
Line Array Element
Frequency Range (-10 dB): 55 Hz – 22 kHz
Frequency Response (+/- 3 dB): 67 Hz – 20 kHz
Horizontal Coverage Angle (-6 dB): 100 degrees nominal (500 Hz – 16 kHz)
Vertical Coverage Angle (-6 dB): Varies with array size and configuration
System Input Power Rating: LF: 1000 W Continuous, 4000 W Peak (AES / 2 hour)
MF/HF: 225 W Continuous, 900 W Peak (AES / 2 hour)
Maximum Peak Output1: 131 to 141 dB SPL, 1m (frequency/bandpass dependent)
Recommended Amplification: LF: 1000 – 2000 W into 8 ohms
MF/HF: 450 – 900 W into 8 ohms
Recommended Signal Processing: dbx®4800, Crown®I-Tech, BSS FDS-366T, and other
Digital System Controllers supported
Transducer Sections
Low Frequency: Two 2168J-1, 203 mm (8 in) dia., 76 mm (3 in) Dual Coil,
neodymium Differential Drive®, Direct Cooled™
Bandpass Nominal Impedance: 8 ohms (16 ohms each transducer, wired in parallel)
Input Power Rating2: 1000 W Continuous, 4000 W Peak (AES / 2 hour)
700 W Continuous, 2800 W Peak (100 hour)
Bandpass Sensitivity: 97 dB, 1W / 1m (2.83 Vrms at 3.3 ft)
Mid & High Frequency: MID: Four 2104H, 101 mm (4 in) with 25.4 mm (1 in) dia.
voice coil
HIGH: Two 2408H, 25 mm (1 in) exit compression driver,
38 mm (1.5 in) voice coil
Bandpass Nominal Impedance: 8 ohms (drivers wired in series-parallel, passive network)
Input Power Rating2: 225 W Continuous, 900 W Peak (100 hour)
Bandpass Sensitivity: 103 dB, 1W / 1m (2.83 Vrms at 3.3 ft)
Enclosure
Box Construction: Wedge frustum 5 degree side angle enclosure. PlyMax®
engineered wood composite structure, DuraFlexTM finish,
2 handles with integrated LF ports
Suspension System: S.A.F.E. hardware, integral hinge bars nest in rigging
tubes on box ends. Quick release pins with restraining
lanyards. Set of 4 hinge bars included. Suspend with
VT4887-AF or VT4887-SF Array Frame.
Grille: Black perforated steel, foam backed
Input Connectors: Neutrik®Speakon®NL-8 and NL-4 (2x each), Pin 3+/- for
Lows & Pin 4+/- for Mid-Highs
Dimensions (W x H x D): 787 mm x 281 mm x 415 mm
(31 in x 11 in x 16.3 in)
Net Weight: 30.4 kg (67 lb)
Shipping Weight: 40.8 kg (90 lb)
1Calculated maximum SPL based on rated peak power and measured sensitivity
2AES Standard, one decade pink noise with 6 dB crest factor within device's operational band, free air. Standard AES 2 hr
rating plus long term 100 hr rating are specified for cone transducers
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.
Compact Bi-Amplified
Three-Way High Directivity
Line Array Element
Application:
The VT4887A Three-Way Line Array Element
is designed to deliver high-quality
reinforcement of music and speech in a
variety of applications including concert
audio and corporate A/V presentations of all
types for both portable users and fixed
venue installations.
Key Features:
䉴 Advanced technology components:
Differential Drive®, neodymium magnet,
dual voice coil, Direct Cooled™ cone
transducers for low weight and high
output.
䉴 New 2168J-1 8" low frequency drivers
offer improved performance and
extended low frequency response
䉴 Proprietary waveguides couple to create
precision HF vertical slot aperture
䉴 Radiation Boundary Integrator®(RBI):
Patented technology integrates output of
individual bandpass elements
䉴 Advanced construction techniques using
JBL PlyMax®engineered wood materials
provide rigid, lightweight enclosure
䉴 Rugged DuraFlex™ exterior finish;
weatherized components
䉴 Integrated S.A.F.E.™ suspension system:
premium heat-treated alloys provide
rigid, reliable hanging arrays
䉴 Pre-engineered to accept optional
amplified electronics package. Rear-panel
mechanical attachments and electrical
connections ensure upgrade path for
DrivePack™ self-powered system
modules with integral signal processing
䉴 For use in stand-alone arrays or in
combination with other VERTEC system
models
The VT4887A is a rugged, compact and
lightweight enclosure housing two 8"
woofers, four 4" midrange radiators, and
two high frequency compression drivers.
VERTEC’s advanced components provide an
extremely high power-to-weight ratio.
Enclosure features foam-backed low
frequency grilles, dense protective foam
inserts for midrange apertures and fine steel
mesh grille to protect high-frequency
apertures. Speaker cones are treated with
weather-resistant compounds.
VERTEC arrays are rigid for maximum
support strength, yet flexible in design and
application. The VT4887A’s suspension
hardware relies on quick-release pins and
end-mounted metal tubes to couple
adjacent VT4887A’s together. Rigging tubes
made of hard-black anodized 6061-T6
Aluminum. Hinge bars made from
premium-grade chromoly alloy steel, with
epoxy powder coating over plated surfaces.
Plated hinge pins and stainless steel quick-
release pin lanyards to resist corrosion and
weather damage. Enclosure ships with
integral front and rear hinge bar set.
Protective grille cover/wheel board and soft
cover ensure handy transport for rough
road conditions, (purchased separately as
VT4887-ACC).
VERTEC®Series
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䉴VT4887A Compact Bi-Amplified Three-Way High Directivity Line Array Element
VT4887A Acoustical Measurements
The frequency response measurement shows composite
response. The Vertical Beamwidth results range from a single box
up to an 8-box array with 10° splay angles between adjacent
array elements.
All measurements provided herewith are derived from data
gathered with a calibrated measurement microphone centered
on-axis of the box or array, with polar data points taken
symmetrically around the measurement axis.
All polars were taken as groundplane measurements at a
distance of 10 meters, with data gathered on 5-degree intervals
from 0-355° using the MLSSA measurement system.
(95˚)
281
(11.0)
(17.2)
437
207
(8.14)
Dimensions in mm (in.)
(29.0)
736.6
(31.0)
787
(29.0)
736.6
(16.4)
415
System Dimensions (WxHxD):
787 mm x 281 mm x 415 mm including attached
suspension hardware
Vertical Beamwidth, Single Line Array Element
20 100 1000 10000 20000
Frequency (Hz)
80
90
100
110
120
SPL (dB)
Frequency Response, On-Axis, Single Line Array Element
Vertical Beamwidth, Four Element Array
(10° splay between cabinets)
Vertical Beamwidth, Six Element Array
(10° splay between cabinets)
Vertical Beamwidth, Eight Element Array
(10° splay between cabinets)
Vertical Beamwidth,Two Element Array
(10° splay between cabinets)
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Horizontal 1/3 Octave Polars
(Single VT4887A Array Element)
Data taken as groundplane measurements at a distance
of 10 meters, gathered on 5-degree intervals from 0-355°
using the MLSSA measurement system.
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䉴VT4887A Compact Bi-Amplified Three-Way High Directivity Line Array Element
Vertical 1/3 Octave Polars
(Single VT4887A Array Element)
Data taken as groundplane measurements at a distance
of 10 meters, gathered on 5-degree intervals from 0-355°
using the MLSSA measurement system.
74665_JBL_VT4887A 5/23/07 10:30 AM Page 4

Vertical 1/3 Octave Polars
(8-Box Array of VT4887A Array
Elements)
Data taken as groundplane measurements at a distance
of 10 meters, gathered on 5-degree intervals from 0-355°
using the MLSSA measurement system.
74665_JBL_VT4887A 5/23/07 10:30 AM Page 5

JBL Professional
8500 Balboa Boulevard, P.O. Box 2200
Northridge, California 91329 U.S.A.
©Copyright 2007 JBL Professional
A HarmanInternational Company
䉴VT4887A Compact Bi-Amplified Three-Way High Directivity Line Array Element
SSVT4887A
CRP5M
05/07
VERTEC System Arrays
The VT4887A is an articulating line array element designed for use in
vertically oriented, multi-box arrays. A nominal horizontal coverage
pattern of 100° is maintained, while setting the individual box angles
allows the creation of arrays with varying vertical coverage angles. Vertical
coverage of an array is a function of the number of boxes used and the
splay angles chosen.
VT4887A enclosures can be suspended from available VT4887-AF or
VT4887-SF array frames. Due to the use of JBL’s S.A.F.E. suspension
hardware system, rigid arrays can be constructed that can be tilted either
upwards or downwards at radical angles. Front hinge bars are tightly
coupled, while rear hinge bars are used to set angles from zero to ten
degrees for adjacent enclosures.
VT4887-AF (Array Frame)
This array suspension frame is crafted of 6061 heat-treated aluminum. It
includes 11 (eleven) attachment holes for shackles, each fitted with bronze
bushings for long life. These holes are set on approx. 4" centers. Each
hole has an I.D. (inner diameter) of 25.4 mm (1 in). Array frames are
fitted with SAE Grade 8 bolts, 7075 Grade aluminum receiver blocks and
steel quick release pins with stainless steel restraining lanyards. The
VT4887-AF can be used to groundstack up to 8 enclosures. Weight: 36 kg
(80 lb).
VT4887-SF (Short Frame)
This array suspension frame is crafted in similar fashion to the VT4887-
AF. The VT4887-SF is primarily intended for use with smaller clusters
in tight spaces or distributed satellite arrays. Optional anchor for use
on bottom of large arrays. Can also be used to groundstack up to 6
enclosures. Weight: 18 kg (40 lb).
VT4887-ACC
The VT4887-ACC includes items necessary for the proper transport and
protection of the VT4887A. This accessory kit includes: (1) VT4887-DOLLY
& (1) VT4887-COVER.
Important Note: The VT4887-ACC is sold as a separate item. One kit
should be ordered with each VT4887A to ensure safe and reliable
transport of each system in portable use.
4-element array,VT4887A, suspended
application with VT4887-AF array frame
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