VerTec System Information 

First product in JBL's new VERTEC series: the VT4889 3-way Line Array System.

FAQ (Frequently Asked Questions)  

A. Vertical Technology. This is an integrated package of line array research, new acoustical elements, a new loudspeaker system that includes them, and a predictive software tool for optimizing the setup of vertical line arrays.  

A. JBL is proud of its heritage in line array research, and its historical products of this type. The lineage, or “technical pedigree” of any company, and its product lines, will affect its ability to draw upon broader, deeper resources in technology when the time comes for developing new product programs.

Q. What products are in the VERTEC Series?

A. The VT4889 3-way line enclosure and accessories, Which include dedicated array hanging frames that are used for suspending or ground-stacking these enclosures. A dolly that latches over the front baffle and a waterproof padded cover bag have been designed for the VT4889.

Q. What are typical applications for JBL’s VERTEC Series?

A. The VERTEC Series is ideal for covering medium to large audience areas at concerts, corporate and civic presentations, worship events, live theatre, film premieres, televised functions and awards shows, sports events, themed attractions, and anywhere that consistent audience-area coverage is important. The system is especially suitable for presenting the live music, the spoken word, and full-bandwidth playback material in acoustically-difficult venues. It can work equally well in smaller indoor facilities or over large distances in outdoor situations.

Q. Can the VERTEC system handle high-level rock music in concert settings?

A. Yes. The system’s components have an output capability that exceed those transducers found in other line array systems of this type.

Q. Why are line array systems popular?

A. When properly designed and assembled, line array systems provide the system designer or operator with a highly consistent, predictable coverage field A properly designed line array system will have reduced component interaction, or comb filtering. in the horizontal plane. This results from assembling all components in a single, ribbon-like vertical “line” that does not have conflicts with similar, adjacent sound radiators pointed in other directions.

Q. Are line arrays a new trend?

A. No. The fundamental acoustic research that led to early line array products took place decades ago. In fact, JBL offered line array systems such as the Model 4682 in the 1970’s. A brief history of line arrays is described in the White Paper, “JBL’s Vertical Technology”.

Q. What is the basic underlying technology in the VERTEC system?

A. The line array summation effect. This is a function of basic physics, and is not the result of any advanced or proprietary engineering. It governs all line arrays, regardless of manufacturer. JBL’s research in this area, new acoustical elements that resulted from this research, the new VERTEC system that includes them, and a proprietary software tool to predict the coverage patterns of VERTEC systems, make up JBL’s Vertical Technology™ platform.

Q. Is the line array summation effect valid for more than just the high frequencies?

A. Yes. In any line array system, pattern control varies with frequency and with the height and size of a line array.

Q. What is the difference between the early “speaker column” line array systems and large-scale modern line arrays like JBL’s VERTEC system?

A.  Early line array systems were typically low-powered systems with all of the components in a single enclosure. They typically relied on small (6”, 8” or 12”) cones. Today’s modern line arrays are made up of modular elements that can be used to create very large, powerful sound reinforcement systems.

Q. Isn’t this just a copy of other line arrays?

A. No. VERTEC is a unique system. It is the first line array system to offer so much output capability in such a small enclosure, to employ high-output dual-coil loudspeaker components in an axially-symmetrical format, and to provide system users with a flexible, lightweight system that can serve such a wide range of applications. JBL’s waveguide and R.B.I. (Radiation Boundary Integrator – Patent Pending) are unique acoustical elements with specific acoustical advantages not found in any other system.

Q. What’s so new about JBL’s VERTEC system?

A. JBL has developed new, high-powered transducers (each with dual voice coils and neodymium magnets for lighter weight and higher output power) and new compression drivers with beryllium diaphragms (for excellent sound fidelity) for the VERTEC system. Patents are in place, or pending, on these components and the elements that shape their acoustical output. Together these technologies give the VT4889 the highest power-to-weight ratio of any product in its class.

Q. Are there differences in the array performance of VERTEC compared to other competitive systems?

A. Yes. Due to the VT4889’s trapezoidal shape, the front baffle of a VERTEC array will always have a smooth, continuous surface, regardless of box angle settings. This has distinct acoustical advantages and ensures that the line array summation effect in not diminished as boxes are angled downwards. And, no ratchet-type straps are required for putting tension on the rear of the array as with other systems. Thus, “No Gaps, No Straps”.

Q. What’s inside the VERTEC system?

A. Each VT4889 enclosure includes (2) lightweight 2255 15” Low Frequency Dual-Coil Differential Drive loudspeakers, (4) powerful 2250H 8” Midrange Frequency Dual-Coil Differential Drive loudspeakers coupled to R.B.I.’s (Radiation Boundary Integrators), and (3) compact 2435 High Frequency drivers fitted to waveguides.

Q. What’s an R.B.I.?

A. A Radiation Boundary Integrator. These midrange frequency acoustical elements couple the high output power capacity of each 2250 8” Midrange speaker to the adjacent low frequency and  high frequency radiating elements in an integrated manner. The R.B.I. serves multiple purposes. It creates slot-loaded compression chambers for the midrange cones while simultaneously smoothing the horizontal response of the high frequency elements. The net result is reduced intermodulation distortion and a more integrated wavefront that is a summation of the output of low, midrange and high frequency elements.

Q. What’s the VerTec High Frequency device like?

A. This specialized waveguide is a high-frequency radiating device with very precise, specific output characteristics enabling it to co-exist and function directly adjacent to others like it in a narrow, vertical ‘ribbon’ pattern. The (3) High Frequency waveguides in each VT4889 system are slot apertures that ensure proper line array summation characteristics at high frequencies.

Q. What does a VT4889 system weigh?

A. Each VERTEC VT4889 enclosure weighs only 72 kg (159 lbs.). This includes all required rigging hardware to connect one box to another.

Q. What is the size and shape of the VT4889 enclosure?

A.  Each box is 1213mm x 489mm x 546mm (19.25 inches tall, 21” deep, and only 47.75 inches wide. It is a trapezoidal shape with 5-degree angled sides.

Q. How does this system pack in a truck?

A. The sizing enables two enclosures to be stacked vertically on end in the smaller box rental trucks frequently used by sound hire companies. Up to 100 of the boxes, with a total weight of 6,895 kg (15,200 lbs.), could be stacked in a (24’) long truck box with a 2,438mm (96”) interior ceiling height (Typical “Ryder” truck). Cabinets can be loaded five wide, two high in standard touring trailer truck bodies.

Q. How is the VT4889 transported?

A. Each box has a dolly that doubles as a protective grille cover. There are eight (8) handles on each enclosure. The soft cover is waterproof and has velcro straps across the bottom to hold it in place. Hard panels in each end of the cover bag protect the rigging hardware in transit.

Q. Besides the VT4889-AF Array Frame, what rigging hardware is required to suspend the boxes in an array?

A. None. All required rigging fittings are integral to the VT4889 enclosure. They comprise sliding hinge bars that retract into tubular, end-mounted metal frames for storage and transit. Once the hinge bars are installed in the rigging frames, there are no extra ‘straps’ or loose fittings to buy, collect and keep track of.

Q. What is the hanging hardware included on each VT4889 box actually like?

A. High-grade alloy frames on the two ends of each enclosure house sliding hinge bars. These can be pinned at positions ranging from 0 to 10 degrees for each adjacent box. They can be set in 1-Degree increments.

Q. How many VT4889’s can be suspended in a single array?

A. Up to eighteen (18) enclosures can be suspended from one VT4889-AF Array Frame with a 7:1 Design Factor.

Q. Can a VERTEC system be ground-stacked or must it always be flown?

A. Yes the system can be ground-stacked. Up to six (6) enclosures can be stacked on the VT4889-AF Array Frame, which can be inverted to support a ground stack. Up to three (3) units can be stacked on the shorter VT4889-SF frame.

Q. Some other systems line array systems use a lower Design Factor, like 5:1. What is the difference?

A. A 5:1 Design Factor means that the suspension hardware will not fail until a stress load of five times the certified weight is encountered. A 7:1 Design Factor means that the suspension hardware will not fail until a stress load that is seven times the certified weight is applied. Different nations of the world have varying regulations concerning the suspension of contained with each enclosure, and JBL recommends that a 7:1 Design Factor be adhered to so that the most stringent regulations are accommodated.

Q. Is the system available for sale?

A. YES. The mass-production build began in November 2000. JBL Professional is accepting purchase orders and shipping VERTEC systems to customers worldwide. Interested customers not already in the build schedule should contact their JBL Regional Representative of International Distributor for obtaining system price and delivery quotes.