No Cookie Cutters

A LCR House System At Valley Bible

by E. Victor Brown

Attaining quality sound reproduction in a church can present a plethora of worthy challenges for even the most skilled system designers and installers. Program material, acoustics, budgets - just a few of the myriad variables that often can and do change from project to project.

"Cookie cutter solutions won't usually do the trick with respect to sound systems in churches," notes Brent Milton, president of Pacific West Sound, Bakersfield, CA-based company that counts church sound as one of its specialties. "Each facility is unique, each culture is unique, service styles and content differs and then all of this subdivides into further variations."

The sanctuary at Valley Bible Church, with EAW AS695 covering the balcony in the foreground.

As a result, Milton notes this his firm's approach is "clean slate." While technical expertise learned over years of system design factors into every project, the charge is to treat all as independent entities requiring their own special solutions. Thorough analysis of both venue and content kicks off a project, done in close collaboration with church staff, leading to system approaches that are then weeded down to a final plan meeting everyone's comfort level. Such was the case with a sound system recently implemented at Valley Bible Fellowship Church, a new,

beautiful 1,000-seat parish also in Bakersfield. Specific facets influencing this design included an acoustically challenging space and diverse contemporary Christian worship services. "We were familiar with Valley Bible through years of providing them with rental systems for a variety of needs," Milton explains. "As a result of that positive relationship, we were asked to offer design/build concepts when planning kicked off for their new building. They ultimately liked out ideas and we were asked to make them happen."

The Valley Bible sanctuary is roughly fan-shaped, with seats spreading wider from a large front platform. A sizable 15-row balcony spans the back of the room, with seating as well as the system control position tucked beneath.

Large expanses of parallel walls contributed mightily to acoustical problems in the space, bouncing energy back and forth unchecked like a ping-pong ball. This problem was given top priority in the design, although the solution - 28 panels covering the largest side and rear wall expanses - wasn't enacted until after the sound system was brought on line. Panels were also applied to the large wall behind the platform to prevent energy "slap" into the sanctuary. Acoustics First of Richmond, VA, noted as acoustical specialists, supplied the expertise on this facet, in cooperation with Pacific West Sound.

Brent Milton of Pacific West Sound

"We had factored the acoustical situation into the sound design, whether it was addressed or not," Milton explains. "The best way to avoid problems is to keep energy off the walls, through use of loudspeakers with tightly controlled dispersion patterns that are carefully aimed at the audience only, as much as possible." At the same time, Valley Bible's services, regularly featuring a full electronic band, dictated a high-output, full-range system, making energy control all the more difficult.

And of course, speech intelligibility ranked highest on the requirement list.

Working with GLS Marketing of Huntington Beach, CA, Pacific West Sound assembled top components that were skillfully merged to address all concerns while also attaining that loftiest of goals: premium sound quality. "Given the width of the room, we focused on a left-center-right loudspeaker system configuration that would supply a stereo music image throughout the primary listening area on the main floor. The balcony and region beneath it, however, would receive a mono feed. "

To attain the left-center-right (LCR) feed to the main loudspeakers, Milton turned to a device suggested by Loren Robinson of GLS, a Miles Technology MTI-3. The unique unit simply takes a stereo signal feed - in this case, supplied by the Mackie SR40 x 8 house console - and through a carefully considered, patented matrixing process called TriSonic Imaging, delivers left-center-right output signal. The center channel is a composite of left and right channels; in other words, it carries significant portions of both channels. The outcome is a center loudspeaker cluster that teams with both left and right clusters to supply a huge stereo listening area. Another benefit of the process is a natural emphasis on vocal signals to center, helping anchor the vocal image to the stage in point-source fashion.

"The MTI-3 is a cool device. It presents a really smooth wall of multichannel sound, open and clean. You can literally hear things in the mix that you couldn't pick out before," Milton says. "At the same time, the center priority on vocals means that you don't have to worry about making any serious adjustments between music programming and spoken word. To the point, the MTI-3 is perfect for an application like this, and there's certainly nothing else like it on the market."

The center loudspeaker cluster, made up of AS Series loudspeakers and the "Batwing."

Using computer modeling, Milton and crew determined optimal loudspeaker positions, both for the main system as well as the subsidiary loudspeakers covering the balcony and underbalcony regions. Main left and right loudspeaker arrays flank the front platform, housed in in-wall chambers covered by fabric scrims that completely conceal them from view. A good deal of effort was devoted to making these chambers as acoustically friendly as possible, including a lining of dual layers of sheet rock that help reduce resonance.

Both arrays are comprised of two tightly packed Eastern Acoustic Works (EAW) AS490 mid/highloudspeaker modules flown above two EAW AS415 low-frequency modules. The center array, flown above the platform, in view, includes dual EAW AS660 three-way loudspeakers separated by a single AS625 subwoofer that fits perfectly within the array structure. A single EAW UB42 compact two-way loudspeaker, dubbed the "Batwing" due to its unique boomerang shape, is attached to the bottom of the array, supplying additional mid/high coverage to the first few rows of seating.

"The AS Series is outstanding for church applications, delivering superior full-range performance combined with the extremely tight pattern control that we always need," Milton

All loudspeakers are driven by Crown Macro-Tech Series amplifiers, with MA-3600VZ's devoted to low-frequency devices and MA-2400’s handling the mids and highs. While Crown amplifiers are a staple of Pacific West Sound's systems, chosen for performance and durability, they also offered another dimension supplying several advantages on this project.

Specifically, each amplifier is outfitted with a Crown IQ-PIP DSP (digital signal processing) card. Simply plugging into the back of each amplifier, the IQ-PIP DSP cards offer complete signal processing capability - equalization, crossover, delay and more - removing the need for outboard processors that would prove more costly and take up much more rack space. In addition, all of the card parameters can be controlled and monitored from a PC loaded with Crown IQ For Windows version 4.0 software residing with the Mackie console at the front-of-house position.

explains. "Like the entire EAW line, the AS Series is extremely deep, offering models that help solve virtually any problem you can imagine. Performance is consistent across the line, so you always know what to expect. We like to think of the AS Series, and EAW in general, as providing a toolbox of solutions."

While the arrays generate solid bass, Milton determined that subwoofers would further bolster low-frequency performance for electronic music, making it solid and tight down to the 40Hz region. As a result, two more special resonance-free chambers were developed under the platform, each housing an EAW SB1000e a low-profile 18-in-loaded subwoofer also popular in high-end concert touring applications.

The Mackie SR40x8, front-of-house console.

'It's great to be able to set up and control the entire system from the mix position. You can actually hear any changes that you're making on the processing parameters. And it's all 24-bit digital processing, precise and pure," Milton notes."Another great benefit is that we have established system presets that are stored in the software.With a simple

click of the computer mouse,the entire system can be reconfigured to provide optimum operation for a given application.

"The exact settings for these preset applications are password protected by the software, preventing any unauthorized changes. "It’s the best of both worlds," he adds. "You’re providing control of the system in a completely simple format, while also not allowing anyone without the proper expertise to just go in and change things at random."

A mono feed, derived from the center channel of the MTI-3, provides signal to the loudspeakers in the balcony and underbalcony regions. Routed first to the IQ-PIP DSP network, this signal is appropriately optimized and time delayed to insure matching arrival times with the main system. Two EAW AS695 three-way loudspeakers are flown, horizontally, above the balcony, while four EAW JF50 compact two-way loudspeakers are mounted on the underside of the balcony, covering seating sections shadowed from primary coverage. Via the presets established on the software, the amplifier channels driving these loudspeakers can be deactivated when coverage to these regions is not needed.

"You might have a wedding where a few hundred people are in attendance, all seated on the main floor," Milton says. "This would make the delay loudspeakers unnecessary, so they should be deactivated to prevent added energy from bouncing around the empty spaces. The beauty of the Crown technology is its versatility, coupled with ease of operation that allows you to virtually set it, and forget it."

Pacific West Sound employed SIA Smaart Pro tuning and analysis software to assist in optimizing the system, both from an overall sonic perspective as well as to seamlessly integrate the coverage of the main arrays with the delays. As usual, they combined this approach with their own experienced ears to arrive at final settings.

Some new microphones, such as an AKG UHF wireless system for the pastor, joined ones retained from the prior system. This same approach was applied with the stage monitoring system, resulting in savings for the customer.

"Their existing monitor gear, while not the latest and greatest, certainly does a nice job. A big key is applying the technology correctly," Milton concludes. "I guess that sums up our approach to projects of this type, which is to do what’s best for the customer, to meet and exceed their needs while also being as practical as possible."

E. Victor Brown is a Michigan-based freelance writer for the pro A/V industry.