Wednesday, July 25, 2007

Alford Media Line Array Solutions - JBL VerTec System

After more than a year of comparing these premier speaker manufacturers’ products, as well as evaluating the opportunities to serve our clients with line array, we decided to add a JBL VerTec line array speaker system to our inventory.

Alford's VerTec speaker elements are easily identified by their custom logo covers. Why did you choose the JBL VerTec? Alford Media has used VerTec in real show situations six times since February. The results have been remarkable…the tracks sound the way you produced them, and as we sound guys like to say, “the lavs are in your face.” In all cases, engineers and clients alike were astonished at the ease of use and the quality of the product. We also recognized the tremendous customer support offered by JBL. Alford Media’s choice of VerTec over other line array offerings was clear-cut. We took delivery of our first twenty-four VT4889s in early August.

What is the JBL VerTec Line Array? JBL VerTec, short for Vertical Technology, is the culmination of over two years of extensive R&D by some of the world’s finest acoustical, mechanical, and show-savvy audio engineers. JBL has long been recognized as the leader in speaker component manufacturing. Not a bad thing when you set out to design, build and market a world class line array speaker system. The charge of the design team at JBL was taking classical line array theory and scale it up to create a large, high powered array. They would need to fully understand line array behavior and develop VerTec and its components from the ground up. JBL was not just trying to be a player in the line array market, but the leader in the field. The time they put into research paid off with the VT4889 array element and the JBL line array calculator.

JBL's line array calculator. The VT4889 uses numerous patented new components such as the high frequency Waveformer™, the Radiation Boundary Integrator™ or RBI™, advanced enclosure design and a rigid pin lock rigging system. It is a tri-amped box utilizing three new drivers designed and built specifically for the VerTec product. Each VT4889 contains two 600 watt 15” light weight woofers, four 300 watt 8” midrange drivers and three 75 watt high frequency compression drivers with beryllium diaphragms.

The JBL line array calculator is the software tool that enables the field engineer to design the system for the event. Most line array manufacturers have a software tool to assist in system design. We have found JBL’s line array calculator to be extremely accurate and a must have tool. The correct pitch of the array bar, as well as the precise angles between the speaker boxes, is critical to the functionality of the array. This is why the calculator is integral to proper system design. By inputting the venue measurements, trim heights and box count, the engineer, in advance of the install, can manipulate the angles and box placement for maximum coverage and optimum frequency response. After extensive field testing, long distance listening, measuring and competitive comparisons, JBL rolled the initial VerTec products out in 2000. The VT4889 is the tried and true flagship of the JBL VerTec product line.

How does Alford handle amplification, processing and power distribution? To this great product, we added Our custom amplifier/processor rack. QSC PowerLight amplifiers and industry standard XTA DP226 DSPs for control. All elements were incorporated into Alford’s proven four box modular design. The end result was a great system with all of the power of a touring rock-and-roll rig along with the assets of a corporate event system.

Our VerTec amplifier/processing racks each consist of three QSC PL6.0’s, one QSC PL236 for a total of over 17,000 watts per rack. Each rack has its own XTA DP226 processor to accommodate the modular design and allow more zone control than typical single processed systems. DP226’s have full front panel controls and can be linked and controlled via RS485 from a remote location, such as front of house. Amplifier output connectivity is routed through nineteen-conductor multi-cable with socopex style connectors that break out to NL8 connectors at the speaker cabinet. The racks are wired for three-phase power for proper AC load balance. We have added new 200 amp AC distribution systems to our inventory to supply the three-phase AC for the VerTec and provide the remainder of the single-phase needs of the show.

The "hook down" rigging system. What does it take to rig the system? Our system also includes digital inclinometers for every array bar. This allows the pitch of the bar, which is critical to the success of the array, to be determined from the ground. The inclinometer sensors are attached to the array frames. The output of the sensors are routed to the reader on the ground via the speaker multi-cable allowing the engineer or rigger to properly set the pitch with chain motors.

The VerTec rigging concept is safe and efficient. In this JBL design, all rigging parts are attached to the cabinet…no loose pieces and no angling contraptions to misplace. It is the most practical design we have seen either in conventional or line array applications. Our array frames are pre-packed in pairs, complete with the inclinometers, shackles, deck chains and spansets. Everything needed for “hook down” rigging is in the pack.

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