Dallas, TX


System overhaul gives new voice to Dallas church

- by Gregory A. DeTogne

Among the angels watching over St. Michael and All Angels Church in Dallas, there is one which was slightly remiss when it came to carrying out his heavenly duties, and that was the Angel of Sound Intelligibility. A figure seldom mentioned within biblical or any other text, it seems this angel (who is known simply as "Jim" among winged friends, and can sometimes be seen running an acoustical analysis program on his PC near the altar) had good intentions when it came to spreading the word inside the church. It's just that, well...architectural acoustics weren't his thing.

"Reverb times are somewhat low in the church, but early reflections are just plain awful," notes Ron Grant of Dallas-based ASC Companies, one of the mere-mortal audio firms chosen to correct the work of the misguided angel. "As a result, intelligibility within the 500-seat sanctuary suffers dramatically. When I first visited the site, I heard a person talking from the front of the church, and after just three words, I couldn't understand what was being said from where I was standing in the back. And that was when the place was nearly dead silent and not one peep was coming out of the sound system."

The battle to tame the house of worship's harsh reflective environment was a campaign waged according to the specifications of a locally-bred blueprint penned by Acoustic Dimensions. As implementers of the design, ASC built two distinct systems to manage the sanctuary's needs, one which supplies house sound reinforcement, and another providing spatial enhancement. Outfitted with a dozen LS432 cabinets from EAW, 16 single-18 subwoofer cabinets, and 10 CF599 ceiling-mounted loudspeakers from Frazier, the house sound system, like the separate spatial enhancement system, features amplification from QSC's CX Series of components.

Operating on a distinctly different--and unique--formula from the house rig, the spatial enhancement system specified by Acoustic Dimensions came from LARES Associates in Belmont, Massachusetts. LARES (which takes its name from an acronym standing for Lexicon Acoustic Reinforcement and Enhancement System) sent principal Steve Barbar to help deploy the system on-site. "LARES is an electroacoustic enhancement system which is capable of electronically reproducing the effects of architectural elements in an environment," he explains. "Within the St. Michael application, microphones within the LARES system were placed in the diffuse field near the choir and other live sound sources. Once captured, that energy is processed using patented DSP technology to overcome the coloration of feedback, thereby producing both sufficient amplitude and reverberation to create a natural acoustic signature throughout the space."

A total of 42 LARES 440K loudspeakers were used in the sanctuary. In its most basic sense, the LARES system takes the fierce acoustical bite out of the room by electronically "moving" its microphones and the loudspeakers in relation to each other so that feedback can never occur. By the time feedback starts happening in one location, the loudspeaker has already moved to another through a large network of independent channels.

Normally, proprietary amplification is utilized with the LARES system, but for this installation, QSC amps were selected in order to maintain systems continuity with the house rig. Capable of producing 250 watts per channel at eight ohms or 400 per channel at four, 10 model CX404 units were rackmounted for use with the LARES 440K loudspeakers, while four more fuel the EAW portions of the house. With high power output and thermal capacity, as well as versatile loading options, each CX404 packs four channels of power into two rackspaces. Also on the house side of the system, five two-channel CX502 amplifiers supply 300 watts per channel to the ceiling speakers, while four two-channel CX1102s provide the ground-shaking electromotive force required of the subs at a rate of 700 watts per channel.

One of the largest QSC dealers in the U.S., ASC makes the amplifiers their first choice based in no small part upon reliability. "The CX Series is a great line of commercial amps," ASC marketing guru Terry Langfitt says. "Based upon our extensive experience with the line, we're not expecting any amplifier-related service calls on this project. On a performance level, they've provided us with a smooth sound in a problematic atmosphere which is very willing to pick up noise."

The St. Michael project was officially completed on January 20th of this year. How does it sound now, you ask? Steve Barbar let ASC's Ron Grant find out early on when he had him stand in the middle of the sanctuary and close his eyes, then walk down the center of the aisle without opening them until he heard the sound drop off.

"As I walked, it literally sounded like two people were holding loudspeakers up to my ears and keeping pace with me right at my sides," he recalls. "When the sound finally dropped off, I opened my eyes and I was standing outside the church. Overall, what's so impressive about this job isn't what you hear, but rather what you don't. Before the upgrade, the echo and intelligibility were so bad you could hardly get through a service. Now, given the clarity, it's hard to believe you're in the same room."

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