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Church Grows With Flexible AV

Crossroads Bible Church transforms a former office space into a worship hall capable of providing its growing congregation with a high-tech worship experience.

Church Grows With Flexible AV

Crossroads Bible Church transforms a former office space into a worship hall capable of providing its growing congregation with a high-tech worship experience.

CHALLENGE: Convert a former office building into a worship hall, distributing sound and video evenly to a 140-foot-wide, 77-foot-deep rectangular space.

SOLUTION: Install loudspeakers capable of eliminating overlapping coverage distortion due to off-axis response, along with 16:9 projection screens to help establish intimacy for people in the back rows.

TO HELP house its rapidly growing congregation, Crossroads Bible Church of Bellevue, WA, desperately needed a larger facility. It was straining to hold weekly services for a congregation that had grown from 800 in 2001 to more than 1,300 by 2004. However, its original 550-seat facility had too many limitations for an expansive remodeling project.

By taking a fresh perspective on the available vacant space in its neighborhood, Crossroads found its new home in a 99,000-square-foot office building, which allowed the church to get significantly more out of a $4.5 million renovation project than building from the ground up.

Transforming the space

By nature, even the nicest office space is far from the soul-uplifting environment of a worship hall. The church enlisted On Point Designs, an Olympia, WA-based AV, lighting, and acoustics design firm, to transform the former office into an environment more appropriate for modern worship.

“The room was 140 feet wide and only 77 feet from the back of the platform to the back wall,” says Jeff Sanderson, senior consultant with On Point Designs. “It seemed impossible to hope for even sound across the wide space without overlapping coverage at the edges of the horn patterns — and we wanted to avoid using bulky speaker cabinets that would detract from the aesthetics. We also wanted to use video to help people 60 feet from the stage feel connected to the worship service without making people at the front feel like they’re in a fishbowl.”


The farther you move off axis in the coverage pattern of any traditional loudspeaker, the greater the frequency response problems that produce uneven coverage and less-than-clear sound — especially in the overlap area between array modules. That’s because the physical distance between drivers and horns in a loudspeaker enclosure creates asymmetry in sound arrival times, especially at the edges of the horn pattern.

While this problem has always plagued loudspeaker designers, EAW’s new, patented Concentric Summation Array (CSA) technology promises to deliver greater clarity in off-axis response. According to the company, CSA couples a coaxial high- and mid-frequency driver to a single horn using a new waveguide/phase plug designed to be “acoustically opaque” to high frequencies while being “acoustically transparent” to mid frequencies.

Another component of the technology involves punching small holes in a crisscrossing spiral pattern derived from the mathematical Fibonacci sequence — represented throughout nature in seashells, sunflowers, and pine cones — across the high-frequency waveguide’s surface. According to EAW, the carefully sequenced holes enable the waveguide to serve simultaneously as two mechanical filters: a low-pass filter for the mid frequencies and a high-pass filter for the high frequencies. The holes are evenly distributed for symmetrical midrange response off axis, yet their randomized shapes and sizes prevent audible high-frequency nulls.

Finally, by positioning a pair of woofers on either edge of the flare, the low frequencies align with the acoustic singularity of the coaxial mid- and high-frequency driver. With rotatable horns inside a dual trapezoidal enclosure, the cabinets form vertical or horizontal arrays to deliver symmetrical beamwidths for covering various audience sizes.

With these goals in mind, Sanderson sought an effective audio solution for the task. He discovered the forthcoming AX Series loudspeakers from EAW, which promised precise coverage in an unusually compact cabinet, thanks to a unique design that eliminates the asymmetrical off-axis response problem in loudspeaker design.

“The shape of the AX cabinets allowed us to easily configure an array horizontally in the front center of the platform,” Sanderson says. “And because of the different horn patterns, we were able to select the perfect combination of cabinets to provide clear, clean sound from one side of the room to the other without overlapping coverage.”

Sanderson worked with Lynnwood, WA-based Morgan Sound to install his designs. The main speaker system comprises four flown EAW AX396s — each featuring a 90- by 60-degree horn pattern — and an AX122 subwoofer installed under the platform. Four Crown CL1s and three CL2s power the speakers, while a BSS Soundweb 9088iis and 9088iis-ML provide speaker control.

The mix of microphones includes three Audio Technica AT4040s, a Crown CM700, and a range of Sennheiser mics, including two MD421s, four E855s, two EW522s, two EW535s, and an EWANT4F. A Yamaha M3000A-40 audio console drives the system, along with a Presonus ACP88 eight-channel gate/compressor/limiter and a Lexicon MPX550 24-bit dual channel processor.

Video intimacy

Sanderson’s design also included a complete video projection system to enable the church to use DVD-and VHS-based presentations during worship services. Although not included in the original project budget, Sanderson chose his components with HD cameras and image magnification in mind for the future. “The sense of intimacy in a large space is lost once you’re 60 to 80 feet away from the platform, so we eventually want to project live video at the front in order to bring intimacy back into the room,” he says.

Sanderson installed two 16:9 Da-Lite Perm-Wall projection screens flanking the central choir platform. The widescreen format of the screens provides future compatibility with technology such as HDTV. “With the screens’ shallow height, we hung them higher on the platform’s back wall, ensuring a clear sightline for people in the back rows while eliminating the in-your-face video experience for those up front,” Sanderson says.

Two Boxlight MP56T projectors installed at the ceiling project onto the screens. Because source gear includes a Denon DVD-900 player and a Panasonic AG-3200 S-VHS player, Sanderson selected an Analog Way Octo-Plus 802 seamless switcher to provide a less-noticeable transition between low-resolution tapes and high-resolution DVDs.

An Analog Way SI-300 universal interface integrates words for worship, sermon notes, and other text overlays from a computer source with other video sources. Because of the distance of the projectors from the booth, an Analog Way QGB-4 distribution amplifier boosts the SI-300’s output signal. A Marshall V-R53P rack-mounted LCD panel provides video monitoring at the booth.

A flexible solution

Because growing pains were so fresh in the minds of the church membership, Crossroads Pastor Dan Perrin also hoped to make the space as flexible as possible. Perrin anticipated the worship hall would host youth events, conferences, and banquet dinners over the next several years. Beyond that, he hoped continued growth would position the church for a future renovation project that would build an even larger worship hall in another part of the building while transforming the present space into a general-purpose activity room.


Sanderson came up with creative plans to house system controls in order to maximize flexibility for the short term, without adding walls that might have to be torn down in eight or 10 years. Sanderson designed two custom-built portable booths on large rolling carts that house the audio and video system controls at the back of the worship space. All of the wiring is hidden in the floor, so when each booth is rolled into place, it can be quickly plugged into a connector box in the floor.

This “booth on wheels” design allows the church to quickly and easily move out the audio and lighting control centers as the needs of the space change. “We designed each booth to look like permanent fixtures that seamlessly blend in with the look and feel of the worship hall,” Sanderson says. “Each booth can be easily disconnected from the floor and rolled into a massive storage room off to the side. This approach allows the church to create more room for banquet seating or other activities that don’t require sound reinforcement or video projection.”

The new space

With its new AV system in place, Crossroads Bible Church opened the doors to its new, expanded facility on schedule in December 2004. “Everyone is delighted with the new space, which has been completely transformed and is virtually unrecognizable as a former office building,” Perrin says. “The sound system is simply amazing. The congregation can spread out and be totally comfortable, yet still hear, see, and feel what’s going on at the platform.”

Meg Mania is a Seattle-based freelance writer who covers technology. She can be reached at[email protected]

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