JBL VTX Series User manual

VTX B28 | User Manual

VTX B28 | User Manual
GENERAL INFORMATION
VTX B28 User Manual
Document Number: 1000346379
Version: A - EN
Distribution Date: July 24, 2020
Copyright © 2020 by HARMAN International; all rights reserved
JBL PROFESSIONAL
8500 Balboa Blvd
Northridge, CA 91329
USA

VTX B28 | User Manual
Thank you for purchasing JBL VTX Series products
In more than 75 years of JBL innovations, the VTX Series stands apart as a milestone in the practical application of cre-
ative engineering. VTX products herald the next generation in line array loudspeaker systems: a new era in performance,
system integration and user friendliness. VTX products draw on multiple JBL patents in driver, waveguide, and suspension
technology, as well as custom amplification, DSP, control, and system management designs created in collaboration with
HARMAN Professional sister companies.
VTX loudspeakers marry custom transducer design and in-house manufacture, breakthrough technologies, and a com-
prehensive system approach to deliver a premium experience for all who come into contact with it, from the FOH mixing
engineer to the systems engineer, rigger, road crew, warehouse manager, and, of course, the audience. Designed for
operators of portable and fixed systems alike, the VTX Series features JBL’s legendary sound quality coupled with expert
support and advanced tools that enable optimal specification, configuration, and operation of VTX systems in any venue,
anywhere in the world. The VTX Series delivers a comprehensive solution: the finest sound quality available, plus efficient
and intuitive setup, tuning, networking, and control.

VTX B28 | User Manual
TABLE OF CONTENTS
1 - SAFETY .................................................................................................6
1.1 Safety Instructions ....................................................................................6
1.2 General Hardware Information ..........................................................................6
1.3 Attachment to Structures ...............................................................................6
1.4 Important Safety Warning ..............................................................................7
1.5 Are You New to Rigging? ..............................................................................7
1.6 Inspection and Maintenance ............................................................................7
1.7 Symbols ............................................................................................8
2 - SYSTEM COMPONENTS ..................................................................................9
3 - COMPATIBLE ACCESSORIES..............................................................................10
3.1 VTX B28 SB - Suspension Bar..........................................................................10
3.2 VTX B28 VT - Vertical Transporter .......................................................................10
3.3 VTX B28 VT CVR - Soft Cover ..........................................................................10
3.4 VTX B28 ACC - Accessory Cover and Caster Board ........................................................11
3.5 VTX B28 GND Ground Stack Accessory ..................................................................11
4 - SOFTWARE.............................................................................................12
4.1 Line Array Calculator 3 TM ..............................................................................12
4.2 Array Link TM ........................................................................................12
4.3 Performance Manager TM ..............................................................................12
5 - OVERVIEW .............................................................................................13
6 - CONNECTIONS .........................................................................................14
6.1 Internal Wiring ......................................................................................14
7 - TRANSPORTATION OPTIONS ..............................................................................15
7.1 Rotating the Dolly Tabs For Use With the ACC Dolly.........................................................16
8 - VTX B28 PRESET LIBRARY................................................................................17
8.1 VTX B28 Preset Modes and Options .....................................................................17
8.2 Time Alignment......................................................................................17
8.3 Product Line Compatibility.............................................................................17
9 - SYSTEM AMPLIFICATION & WIRING ........................................................................18
9.1 B28 Using Crown I-Tech 12000HD ......................................................................18
9.2 B28 Using I-Tech 4x3500HD...........................................................................19
9.3 Crown V-Rack ......................................................................................20
10 - CARDIOID CONFIGURATIONS ............................................................................21
10.1 Recommended Cardioid Setups .......................................................................22

VTX B28 | User Manual
10.2 Minimum Space Between Cardioid Stacks ...............................................................23
10.3 Minimum Space from a Wall ..........................................................................24
10.4 Flown Array Configurations ...........................................................................25
11 - CARDIOID PRESETS IN PERFORMANCE MANAGER .........................................................26
12 - TESTING THE VTX B28 ..................................................................................27
12.1 Using a DMM (Digital Multi meter) ......................................................................27
12.2 Using Performance Manager ..........................................................................28
12.3 Performance Manager Readings .......................................................................28
13 - SPECIFICATIONS .......................................................................................29
13.1 VTX B28 ..........................................................................................29
14 - ACOUSTIC MEASUREMENTS ............................................................................30
15 - DIMENSIONS ..........................................................................................30
16 - CONTACT INFORMATION ................................................................................31

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VTX B28 | User Manual
1 - SAFETY
1.1 SAFETY INSTRUCTIONS
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not expose the product to direct rain or sea spray.
6. Clean only with a dry cloth.
7. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus that produce heat.
8. Only use attachments/accessories specified by the manufacturer.
9. Use only with a cart, stand, tripod, bracket, or table specified by the manufacturer or sold with the apparatus. When a cart is used,
use caution when moving the cart/apparatus combination to avoid injury from tip-over.
10. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as if
liquid has been spilled or objects have fallen into the apparatus, or if the apparatus has been exposed to rain or moisture, does not
operate normally, or has been dropped.
11. Contact JBL Professional for advanced servicing issues.
12. CAUTION - DO NOT PERFORM ANY SERVICING UNLESS YOU ARE QUALIFIED TO DO SO.
13. Prolonged exposure to excessive SPL can cause hearing damage. The loudspeaker is easily capable of generating sound pressure
levels (SPL) sufficient to cause permanent hearing damage to performers, production crew, and audience members. Caution should
be taken to avoid prolonged exposure to SPL in excess of 90 dB.
14. Read the System Rigging Manual before installation and use of the product.
1.2 GENERAL HARDWARE INFORMATION
Any hardware used in an overhead suspension application must be load rated for the intended use. Generally, this type of hardware
is available from rigging supply houses, industrial supply catalogs, and specialized rigging distributors. Local hardware stores do not
usually stock these products. Compliant hardware will be referenced with a working load limit (WLL) and a traceability code.
1.3 ATTACHMENT TO STRUCTURES
A licensed Professional Engineer must approve the placement and method of attachment to the structure prior to the installation of any
overhead object. The following performance standards should be provided to the Professional Engineer for design purposes: Uniform
Building Code as applicable, Municipal Building Code as applicable, and Seismic Code as applicable. The installation of the hardware
and method of attachment must be carried out in the manner specified by the Professional Engineer. Improper installation may result in
damage, injury, or death.

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VTX B28 | User Manual
1.5 ARE YOU NEW TO RIGGING?
If you are new to rigging, you should:
• Know the rules for safe rigging.
• Attend a safe rigging seminar.
• Meet and establish a relationship with a licensed mechanical or structural engineer. Get in the habit of asking them questions in-
stead of assuming their answers. Learn from what they tell you.
• Research and understand the codes, practices and requirements of the venues where you intend to operate your sound system.
1.4 IMPORTANT SAFETY WARNING
The information in this section has been assembled from recognized engineering data and is intended for informational purposes only.
None of the information in this section should be used without first obtaining competent advice with respect to applicability to a given
circumstance. None of the information presented herein is intended as a representation or warranty on the part of JBL. Anyone making
use of this information assumes all liability arising from such use.
All information presented herein is based upon materials and practices common to North America and may not directly apply to other
countries because of differing material dimensions, specifications, and/or local regulations. Users in other countries should consult with
appropriate engineering and regulatory authorities for specific guidelines.
Correct use of all included hardware is required for secure system suspension. Careful calculations should always be performed to
ensure that all components are used within their working load limits before the array is suspended. Never exceed the maximum recom-
mended load ratings.
Before suspending any speaker system, always inspect all components (enclosure, rigging frames, pins, eyebolts, track fittings, etc.) for
cracks, deformations, corrosion, or missing/loose/damaged parts that could reduce strength and safety of the array. Do not suspend
the speaker until the proper corrective action has been taken. Use only load-rated hardware when suspending JBL suspendable loud-
speaker models.
1.6 INSPECTION AND MAINTENANCE
Suspension systems are comprised of mechanical devices and, as such, require regular inspection and routine maintenance to ensure
proper functionality. Before suspending or pole mounting any speaker system, always inspect all components (enclosure, suspension
frames or brackets, pins, eyebolts, etc.) for cracks, deformations, corrosion, or missing/loose/damaged parts that could reduce strength
and safety of the array. Do not suspend or pole mount a speaker until the proper corrective action has been taken.
Installed systems should be inspected at least once a year. The inspection must include a visual survey of all corners and load-bearing
surfaces for signs of cracking, water damage, delamination, or any other condition that may decrease the strength of the loudspeaker
enclosure.
Accessory suspension hardware provided with or for VTX systems must be inspected for fatigue at least once a year or as required by
local ordinance. The inspection must include a visual survey of the material for signs of corrosion, bending, or any other condition that
may decrease the strength of the fastener. Additionally, any eyebolts must be checked for possible spin-out of the enclosure.
For all other hardware and fittings, refer to the hardware manufacturer’s inspection and maintenance guidelines for process.

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VTX B28 | User Manual
1.7 SYMBOLS
The following symbols are used in this document:
CAUTION: This symbol gives notice of a potential risk of harm to the individual or the equipment. Instruction
marked with this symbol must be strictly followed.
TIP: This symbol gives notice of helpful, relevant information about the topic.
INSTRUCTIONS: This symbol gives notice of instructions that must be followed for proper installation and use of
the product.
TOOLS REQUIRED: This symbol gives notice of tools that must be used for proper installation and use of the
product.
JBL is not responsible for the application of its products for any purpose or the misuse of this information for any purpose. Furthermore,
JBL is not responsible for the abuse of its products caused by avoiding compliance with inspection and maintenance procedures or
any other abuse.
Prior to suspending the system, an expert, trained and experienced in suspending speaker systems, should inspect all parts and com-
ponents.

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VTX B28 | User Manual
2 - SYSTEM COMPONENTS
VTX B28
Crown I-Tech HD Amplifiers Crown V-Rack
Menu/Exit
Prev
Next
Power
Bridge 1/2
Bridge 3/4
Data
DRIVECORE SERIES
Fault
Thermal
Clip
-10
-20
Signal
Ready
1234
Fault
Thermal
Clip
-10
-20
Signal
Ready
1
Power
Bridge 1/2
Bridge 3/4
Data
Menu/Exit Prev Next
Fault
Thermal
Clip
-10
-20
Signal
Ready
2
12

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VTX B28 | User Manual
3.1 VTX B28 SB - SUSPENSION BAR
3 - COMPATIBLE ACCESSORIES
The accessories listed below are compatible with the VTX B28. For more detailed information about the B28 accessories refer to the VTX
B28 Rigging Manual found at www.jblpro.com.
• Versatile suspension bar accessory for B28 subwoofer
• Single-point and dual-point support
• Secondary safety attachment points included
• Support for (16) B28 enclosures
• Lightweight, fully symmetric design
• Shackle Size: 5/8 inch
3.2 VTX B28 VT - VERTICAL TRANSPORTER
• Vertical transport cart for up to four VTX B28 enclosures
• Truck-friendly dimensions
• Built-in stacking features for easy storage
• Lightweight aluminum design
• Heavy-duty tour-grade casters
• Compatible with the VTX A12 VT GND
3.3 VTX B28 VT CVR - SOFT COVER
• Heavy-duty soft cover for VTX B28 stacks
• Covers three or four VTX B28 enclosures
• Includes input-panel flaps for testing purposes
• Clear see-through pocket for shipping labels
• Handle cutouts for easy transportation
• Heavy-duty industrial-grade zippers
• Foldable design for storage

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VTX B28 | User Manual
3.4 VTX B28 ACC - ACCESSORY COVER AND CASTER BOARD
• Transportation kit for VTX B28
• Includes protective cover and caster board
• Handle cutouts and rear panel access flap
• Tour-grade casters
• Stackable for convenient storage
• Rotating locking cam mechanisms for secure attachment to B28 en-
closures
CAUTION: Always use components and accessories specified and approved by JBL Professional. When a cart is
used, use caution when moving the cart to avoid injury from tip-over.
3.5 VTX B28 GND GROUND STACK ACCESSORY
• Improves stability of ground stacks built on the B28 subwoofer
• Attaches directly to B28 integral rigging
• Simple two-part design
• Lightweight

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VTX B28 | User Manual
4 - SOFTWARE
4.1 LINE ARRAY CALCULATOR 3 TM
LAC is simulation software for designing and predicting VTX Se-
ries systems. LAC predicts the acoustical performance of line array
systems, as well as flown and ground-stacked subwoofer arrays.
Subwoofer delay values can be generated for electronic delay
steering (EDS) using the built-in coverage calculator. LAC also per-
forms mechanical validation of rigging hardware, calculates weight
limits, and generates safety warnings.
www.jblpro.com/lac3
4.2 ARRAY LINK TM
Array LinkTM is a mobile companion app that works in conjunction
with LAC software to assist in deployment of VTX Series systems.
Array Link uses a QR code system to transfer all mechanical ar-
ray information from the main LAC application to a mobile phone.
All relevant rigging and mechanical options are presented in an
easy-to-understand layout. The application is compatible with
iOS® and AndroidTM and can be obtained from their respective
app stores.
4.3 PERFORMANCE MANAGER TM
Performance Manager™ is a configuration and control applica-
tion for networked audio systems. Performance Manager’s user
interface guides system designers through the complete system
design, configuration, and control processes. A dedicated show
mode provides all monitoring and control functions needed to de-
liver a complete picture of the system’s performance in real time.
www.jblpro.com/performancemanager

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VTX B28 | User Manual
The B28 shares the industrial design of the VTX A-Series
products, and features an innovative and simple-to-use two-
point rigging system. The all-captive rigging system utilizes a
spring-loaded mechanism to deploy the link bars and a unique
locking system that complies with all safety requirements without
using traditional quick release pins. B28 subwoofers can be de-
ployed in omnidirectional or cardioid arrays, ground stacked, or
in suspended configurations of up to 16 enclosures.
5 - OVERVIEW
The VTX B28 is JBL Professional’s next-generation dual 18-inch subwoofer, designed to complement the company’s flagship VTX
full- range sound reinforcement systems. The VTX B28 features two JBL 2288H-M 18-inch woofers engineered for improved linearity,
efficiency, and extra-long excursion. The 2288M employs Differential Drive – JBL’s dual voice coil, dual gap technology – to deliver bet-
ter heat dissipation, lower power compression, and wider dynamic range than conventional single-coil designs. The B28 incorporates
a double-flared, exponential, low frequency port design to improve airflow and reduce audible turbulence, even at high output levels.
RIGGING SYSTEM
The B28 uses a simple and innovative two-point rigging system
capable of suspending arrays of up to 16 B28 enclosures. Rigging
components are hidden behind the two wooden side panels, and the
two link bars are deployed by a spring-loaded mechanism. A unique,
all-captive locking system secures cabinets together using a set of
levers and sliding pins. The mechanism includes a safety lock to pre-
vent unintentional release, and complies with all safety requirements.
When B28 cabinets are ground stacked, the all-captive design keeps
unused parts hidden and damped from rattling.
CONTROLLABLE COVERAGE
The B28 makes it simple to form omnidirectional or cardioid arrays.
Speaker connectors are available on both front and rear panels,
streamlining cable management in either configuration.
SYSTEM SOLUTION
The VTX Series is a comprehensive family of hardware and software
products and accessories that work together to facilitate the com-
plete event workflow, from system design to transport home. Tools
support tasks every step of the way.
PERFORMANCE
The 2288H-M 18-inch woofers are engineered from the ground up to
deliver transparent, linear bass response down to 25 Hz. This driver
leverages JBL’s patented, fourth-generation, Differential Drive tech-
nology to deliver maximum sensitivity and power handling in a light,
compact design. The B28 is intended to provide accurate very low
frequency coverage adequate for the most demanding applications.

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VTX B28 | User Manual
6 - CONNECTIONS
The VTX B28 is equipped with two Neutrik NL4 speakON connectors, one on the rear of the cabinet and one on the front. The 18-inch
woofers inside the B28 are wired in parallel from pins 1+/1- of the NL4 connectors. Since this results in a nominal load of 4 ohms, dai-
sy-chaining subwoofers is not recommended. The NL4 connector on the front is typically used in cardioid configurations, where some
enclosures are pointed rearwards, to keep the cable run on the back of the array. All NL4 connectors are installed upside down so that
the NL4 locking pin position can be seen from under the array.
CAUTION: Always use high-quality insulated speaker cables made by reputable manufacturers. Keep cable length
as short as possible with a sufficient wire gauge for the application.
6.1 INTERNAL WIRING
1+
1-
2+
2-
1+
1-
2+
2-
SUB
FRONT NL4 REAR PANEL NL4
SUB
Rear NL4 ConnectorFront NL4 Connector

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VTX B28 | User Manual
TIP: For additional information on how to use and deploy the ACC and Vertical Transporter refer to the VTX B28 Rigging
Manual, which can be downloaded from the JBL Professional website.
7 - TRANSPORTATION OPTIONS
B28 subwoofers can be transported singly or in stacks. The VTX B28 VT Vertical Transporter cart allows transporting stacks of up to
four B28 subwoofers. When stacked in blocks of two, three, or four, B28 cabinets can be transported in either front-firing or cardioid
configurations. The VTX B28 VT CVR, a reinforced cover, is available for protecting subwoofers during transportation. The VT option is
ideal for large-scale touring situations where large format trucks are used and maximum deployment efficiency is needed. Single B28
cabinets can be transported using the VTX B28 ACC accessory kit, which includes a front-face dolly and a protective cover. The ACC
option is more agile and efficient for transportation, as it allows stacking B28 subwoofers on top of other equipment in the trucks.
VTX B28 VT
VTX B28 ACC

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VTX B28 | User Manual
STEPS:
• Remove the four M6 HEX bolts holding the bracket onto the B28.
• Rotate the bracket to the extended position.
• Install the bolts.
• Repeat for the other side.
1
2
7.1 ROTATING THE DOLLY TABS FOR USE WITH THE ACC DOLLY
Two dolly tabs at the front of the B28 are used to secure the front-face ACC dolly board to the B28. The tabs are retractable and ship
from the factory in the retracted position inside the B28. This orientation is ideal when B28s are on a vertical transport cart, where the
tabs are not needed, but the tabs must be rotated to attach a front-face dolly board to the B28.
3
4
1
2 2 3
4
TOOLS REQUIRED: A Torx T25 wrench is required to remove the four bolts holding the ACC brackets. All bolts should
be torqued to 2.82 N.m (25 in.lbs).

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VTX B28 | User Manual
8 - VTX B28 PRESET LIBRARY
The VTX B28 preset library includes 60 and 80 Hz operating modes along with cardioid presets for rear-facing subwoofer enclosures.
VTX presets are exclusively developed for Crown I-Tech HD amplifiers and come bundled with Performance ManagerTM control software.
Audio Architect presets are also available and can be downloaded from the JBL Pro website. See below for a detailed description of the
B28 operating modes and processing options, and refer to the Preset Library setup sheets for preset descriptions, memory locations
and output channel assignments.
8.1 VTX B28 PRESET MODES AND OPTIONS
VTX B28 60: The 60 Hz preset mode extends the upper frequency response of the B28 to 60 Hz. The B28 60 preset is normally used
when VTX full-range cabinets, such as the A8 or A12, are used in full-range mode and minimal overlap between the subwoofers and
full-range cabinets is desirable.
VTX B28 60 REAR: The 60 Hz Rear preset is designed to perform the same function as the standard B28 60 preset for rear-facing B28
cabinets in cardioid configurations.
VTX B28 80: The 80 Hz preset mode extends the upper frequency response of the B28 to 80 Hz. The 80 Hz preset is normally used when
VTX full-range cabinets, such the VTX A8 or A12, are set to an 80 Hz cutoff.
VTX B28 80 REAR: The 80 Hz Rear preset is designed to perform the same function as the standard B28 80 preset for rear-facing B28
cabinets in cardioid configurations.
8.2 TIME ALIGNMENT
The VTX B28 presets provide proper system summation with companion VTX full-range cabinets (all models) in physically coupled con-
figurations (stacked or suspended), and when used with corresponding 60 or 80 Hz presets. This pre-alignment is done at the factory,
allowing any VTX subwoofer to be used with any VTX loudspeaker without subwoofer presets specific to each system and configuration.
Additional time alignment delay should be added as needed to account for physical path length differences between suspended full-
range arrays and ground-stacked VTX subwoofers.
VTX A8VTX B18 VTX A12 VTX B28
8.3 PRODUCT LINE COMPATIBILITY
The VTX B28 acoustical characteristics are compatible with those of the VTX B18. VTX B28 and B18 can be combined together in the
same system or array without summation problems. In arrays combining the B28 and B18 (or any other VTX subwoofer), all subwoofers
should be operated in the same mode. Mixing 60 Hz and 80 Hz presets in the same system or array is not recommended.

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VTX B28 | User Manual
9 - SYSTEM AMPLIFICATION & WIRING
The VTX B28 subwoofer, like all other VTX systems, is powered exclusively by Crown I-Tech HD amplifiers, providing consistency and
optimum performance anywhere in the world. All B28 processing is performed using the I-Tech HD’s internal processing, which includes
the advanced LevelMaxTM three-stage limiter suite, ensuring proper, reliable B28 operation under any conditions. LevelMax incorporates
excursion control, RMS limiting, and long-term thermal protection for the woofers. The I-Tech HD amplifiers also offer a user-adjustable
input section for equalization, time alignment, and electronic delay steering. Standard JBL presets are available for both the Crown
I-Tech 4x3500HD and I-Tech 12000HD. The most up-to-date presets are available for download from www.jblpro.com, and bundled in
the latest version of Performance ManagerTM control software.
9.1 B28 USING CROWN I-TECH 12000HD
The Crown I-Tech 12000HD is the recommended amplifier for powering VTX B28 subwoofers. Two VTX B28 subwoofers (one per chan-
nel) can be powered by each amplifier. The example below shows how to connect two VTX B28 cabinets to a two-channel I-Tech HD
amplifier using two standard NL4 (or NL2) cables.
VTX B28I-TECH 12000HD
NL4 Cable
Amplifier Rear Panel
Amplifier Rear Panel
Alternatively, a cable splitting an NL4 to two NL2 connectors can be used, which allows connecting a pair of B28 subwoofers using a
single four-conductor NL4 cable. This can reduce cabling requirements by a factor of two. The NL4 connector for channel A on the
amplifier must be used In this configuration, as it carries both channel signals, while the channel B connector does not.
NL4 Cable
CH-1
CH-2
CH-1
CH-2

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VTX B28 | User Manual
9.2 B28 USING I-TECH 4X3500HD
When using Crown I-Tech 4x3500HD amplifiers, up to two VTX B28 subwoofers can be powered per amplifier and the remaining chan-
nels can be used to power a JBL full-range speaker, such as the VTX A8. The example below illustrates how to connect two VTX B28
cabinets to a four-channel I-Tech HD amplifier using standard NL4 (or NL2) cables. In the example below, the two subwoofers are con-
nected to amplifier channels 1 and 3 using the two NL4 output connectors. Channels 2 and 4 are available and, with an NL8 connector,
can be used to power other speakers.
CH1/CH2CH1/CH2 CH3/CHCH3/CH44
OUTPUTSOUTPUTS
Amplifier Rear Panel
I-Tech 4x3500HD
Amplifier Channels
Channel 1 B28 1
Channel 2 B28 2
Channel 3 A8 LF
Channel 4 A8 MHF
Alternatively, a cable breaking the NL4 connector out to two NL2 connectors can be used to drive one B28 each from amplifier channels
1 and 2. A four-conductor NL4 cable is employed in this arrangement, reducing cabling requirements. Amplifier channels 3 and 4 remain
available for driving a full-range product, such as the VTX A8.
CH1/CH2CH1/CH2 CH3/CHCH3/CH44
OUTPUTSOUTPUTS
Amplifier Rear Panel
I-Tech 4x3500HD
VTX B28
VTX A8
NL4 Cable
NL4 Cable
NL4 Cable
CAUTION: Attempting to drive more than two B28 enclosures from a single 4X3500HD is not recommended and
may degrade performance and compromise long-term thermal capabilities of the amplifier.
CH-1
CH-3

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VTX B28 | User Manual
Connecting four B28 subwoofers to a Crown 4x3500HD amplifier is generally not recommended for high SPL applications, but can be
done in situations where maximum SPL is not a primary objective of the system design. This configuration requires a cable breaking an
NL8 out to four NL4 connectors, allowing connection of one B28 subwoofer to each amplifier channel.
Amplifier Channels
Channel 1 B28 1
Channel 2 B28 2
Channel 3 B28 3
Channel 4 B28 4
CH1/CH2CH1/CH2 CH3/CHCH3/CH44
OUTPUTSOUTPUTS
Amplifier Rear Panel
NL8 Cable
VTX B28
I-TECH 4x3500HD
9.3 CROWN V-RACK
VTX Series systems are compatible with the Crown V-Rack 12000HD and Crown V-Rack 4x3500HD touring racks. The number of cab-
inets supported by each amplifier and wiring options remain the same as the Crown I-Tech examples illustrated in this document. For
more information on Crown V-Rack products, refer to the V-Rack User Manuals and documentation.
CAUTION: Using four B28 subwoofers on a single I-Tech 4x3500HD amplifier is NOT recommended for high SPL ap-
plications. In high SPL situations, drive one or two B28s from each four-channel amplifier. Alternatively, the two-channel
I-Tech 12000HD amplifier can be used.