House Of Worship

Array Of Hope

Diversified erases a client’s line-array aversion with modern tech and ingenious design.
Photos courtesy Randy Foster.

In order to deliver the moving musical performances and uplifting sermons that are a hallmark of contemporary worship, a modern-day church needs to keep its AV systems current, if not cutting edge. So, when Josh Cash was hired to be the new Tech Director at The MET Church (Houston TX), he made upgrading the venue’s outdated speaker system his top priority.

Although the church’s services had evolved with the times to incorporate a full praise band with electric instruments and a broadcast-caliber approach to video production, its audio was a different story. Prior to Cash’s hiring, The MET Church’s Jones Road campus had not undergone a major sound system overhaul since a building expansion in 1997. A few new consoles and other components notwithstanding, the bulk of the sound system was about 20 years old. And, to make matters worse, the system’s engineering left a lot to be desired.

“We had three clusters of large boxes from a well-known manufacturer,” Cash recalled. “By the time I got there, they weren’t even using the center cluster. We reprogrammed all the engineering to get rid of the center cluster and run stereo out of the remaining boxes. It was messy. And, the way the boxes were hung, there was a bunch of space in between the clusters. So, no area in the room sounded like any other area.” The system’s low end was even worse. “We had our subs on the floor, and we had a huge power alley in the center and just no low end anywhere else, until you got under the balcony in the back,” Cash continued. “When you got out to the sides, it was all high-mid. So, basically, we had zero even coverage, tonally. When people would talk about the sound, you always would have to say, ‘Where were you sitting?’ And I wanted to get rid of that question.”

A system failure that occurred while Cash was out of town proved to be the last straw for the old system, and The MET Church decided to put the project out for bid. Diversified submitted the winning bid, thanks to some innovative ideas from Design Engineer Scott Clark. As it turns out, Clark and Cash go way back, having crossed paths several times over the years in various worship AV-related roles; thus, Cash was more than confident that Clark was up to the task. “Scott’s just an amazing engineer,” Cash said. “I’ve seen him knock out re-tuning a room in 40 minutes many times.”

The MET Church’s Jones Road campus sanctuary is pretty typical as far as worship spaces go. The room seats about 2,000, and its most challenging features from an acoustic standpoint are the height and width of the seating area. “The worship center is the standard Baptist church: a fan-shaped room with raked pews that go up side loges all the way to the balcony,” Clark explained. “The stage is more contemporary, but the seating is more traditional. It’s a fairly tall seating shape, with a reasonably short back wall—from the edge of the stage to the back wall is about 120 feet. Like most churches, you’re not really doing an extremely long throw; you’re doing what I would call a medium throw. But, you’re doing a lot of vertical coverage, and that can present issues in terms of design.”

Clark presented a variety of possible system designs in Diversified’s bid, and that level of meticulousness won over not only Cash, but also The MET Church’s management. “Scott came in, and he showed us a couple of different ways we could approach the room,” Cash said. “We could do a traditional line array, and he showed us how the boxes would interact with each other, and how it would play out in the room. Or, we could do what a lot of people would do—a mono system with a bunch of boxes to give even coverage throughout. But Scott showed us that, with that approach, when you hit the phase button, the room looks like a stinkin’ tiger with all these phase stripes.”

For his part, Cash knew exactly what he wanted from the new system. “I wanted it to sound the same everywhere,” he stated. “And I wanted stereo for music. But I also didn’t want people to be drawn to the sides when somebody’s teaching, which is half of our service, and I think the most important part. So, I wanted center localization, as well.”

With Cash’s design criteria and the phasing issue in mind, the mono system was out of the question. However, Cash also had misgivings about moving forward with a line array. “I don’t like line arrays, because the boxes interact with each other,” Cash explained. “When you walk the pattern vertically, you hear the change. The interaction between the boxes is so clear. I absolutely hate that. And I think the individual boxes sound good. But then, when they’re set up in an array, and the way they’re designed to work, you’ve got interaction right out of the box. It drives me nuts.”

Clark knew that he would have to find some way to make a line-array system more palatable to Cash. According to Clark, the problem that Cash has with most line-array systems has to do with gaps in high-frequency coverage. However, solving the problem in that particular space wouldn’t be easy. “In a room that’s so vertical in terms of the amount of coverage that you need, for a standard line-array element to handle that kind of vertical space without high-frequency gaps, you need a high number of boxes to accomplish it,” Clark said. “And that drives the cost out of the range of the budget.”

Fortunately, line-array technology has advanced to the point that Clark was able to devise a solution to the gaps in high-frequency coverage, without blowing up the budget. He decided that a system based on Bose ShowMatch components would do the trick. “One of the reasons for choosing Bose was that, with the products that are available today, it’s really nice and easy to design an array system that has a lot of vertical coverage, with fewer boxes, that doesn’t have any high-frequency gaps,” Clark said.

The new speaker system consists of two main arrays arranged in left/right configuration and flown above the stage. Each of the main arrays consists of five Bose SM5s, one SM10 and two SM20s (equipped with SM20WG12 waveguides). A center array was also installed in between the left/right arrays to satisfy Cash’s design criteria for center localization. It consists of one SM5, two SM10s and two SM20s (equipped with SM20WG12 waveguides).

“The stage is really wide, and so is the room, so we went with a wide stereo configuration,” Clark explained. “And wide stereo can be really bad for localization off center. So, the trick was to use a center array that is not independent of left and right; it just gets a mix of the left and right signal. And its only reason for being there is localization.”

The effect of drawing the audience’s attention to the center array without having it interact with the main arrays is achieved through some ingenious engineering. “So, you have a center array and, if you’re careful, you can have it not interact negatively with left and right but, rather, have it draw people’s attention toward the center of the stage, because it’ll be the first source that hits those people,” Clark explained. “In order for it to localize, it doesn’t have to be as loud as the second source of energy. And that’s part of the trick in having it not interact negatively with left and right, because the center array is down in level.”

Clark continued, “You can do this through processing, but also through the natural output of the array. With variable-pattern speakers, if the speaker has a wider pattern, then, at a given point in space, it’s not going to have as much energy, so it’s going to have less volume at that point. By using only five speakers in the center, instead of eight, the center speakers have a wider pattern than the arrays on the left and right. So, there’s not as much energy at one point in space from the center as there is from left or right. You can accomplish that acoustic attenuation with a wider-patterned speaker. And then you can fine-tune the levels in processing.”

That met Cash’s stated goal of a stereo configuration for music and center localization for spoken word, and the system also met The MET Church’s requirements for musical performances. “They didn’t want rock ‘n’ roll levels, necessarily,” Clark recalled. “They’re not going to be running 100dB A-weighted and above on a Sunday morning. But, there are a lot of professional artists who go to that church, and they have concerts there. So, they wanted the room to be able to get to that kind of concert-level sound. We designed for over 110dB A-weighted at the back wall. And, on the low end, they wanted the kick drum to hit you in the chest a little bit, but they didn’t want to put in 16, 20 or 24 subwoofers to get there.”

A smaller center localization array is flown in between the main left/right arrays. Two flown subwoofer arrays are placed behind the center array, facing each other to create a cardioid pattern.
A smaller center localization array is flown in between the main left/right arrays. Two flown subwoofer arrays are placed behind the center array, facing each other to create a cardioid pattern.

For the low end, Clark specified two flown subwoofer arrays. “One of the things Josh wanted to accomplish was for the system not to be as heavy in the front rows as compared to the rest of the room,” Clark said. “So, we decided to do two subwoofer arrays, one behind the other. Each array consists of four SMS118 subwoofers. Both of those arrays are behind the center localization array, and they’re spaced apart 68 inches face to face. That provides a nice cardioid pattern to minimize energy behind the speakers going up behind the stage wall and into the ceiling.”

Clark also applied a personal engineering touch to the flown arrays. “One of the techniques that I’ve pioneered is what I call a ‘phase-aligned overlap,’ which ends up being a dynamic crossover point between the mains and the subs,” he explained. “What that does is create an overlapped set of frequencies that the mains and the subs work together in. As long as they’re phase-aligned in that overlapped set of frequencies, it doesn’t matter the relative level between the mains and the subs—wherever they are matched in level, it’s phase aligned.”

Dante-enabled mixing consoles were added to the front of house and monitor mixing positions, as well as the control room.
Dante-enabled mixing consoles were added to the front of house and monitor mixing positions, as well as the control room.

Additional speakers include four RoomMatch Utility RMU208s, which are used as under-balcony fills, as well as two Bose Panaray LT 9702 WRs. “The Panarays are located just to the outside of the left and right main arrays,” Clark said. “They are used as side-fill speakers for a very narrow slice of the front corner of the space that is not being covered in the high frequencies by the left and right arrays. So, we rotated these speakers to be 90° in the vertical and 70° in the horizontal, and they’re filling in just the front corners of the space.”

A total of 12 Bose PowerMatch PM8500N amplifiers power the speakers. “The 8500Ns are eight-channel amps that you can bridge and also group into four channels per output,” Clark said. “The subwoofers require four channels each, so one amplifier can handle two subwoofers each. With ShowMatch, the low frequency needs two channels bridged, and the high frequency needs one channel. And we supplied power to each box individually, so there are no boxes that are paralleled with the line-array speakers. The side fills are paralleled and the under-balcony fills are in pairs.”

A Bose ControlSpace ESP-880 with a Dante expansion card is used for digital signal processing. A Behringer X32, also with a Dante expansion card, is located in the church’s control room, and it handles the bulk of the mixing. “Our computers are now all running Dante,” Cash stated. “And we’ve got a couple of analog components that go into the Behringer and then out through Dante. It really cleared up a lot of space in the control room, and it made it a lot simpler to do things. We run Ableton, and that’s now run through Dante, which is awesome, because we use a lot of tracks.” In addition, two Avid VENUE S6L consoles are used for front of house and monitor mixing. Each rack location features a Cisco SG300-10 network switch. Equipment is housed in Middle Atlantic racks, and five Middle Atlantic UPS-S1000Rs provide backup power to the system.

Audio inputs include two VENUE Stage 64 stage boxes equipped with analog cards and Dante cards. Microphones include Shure ULXD wireless mics and handheld Beta 87 capsules, as well as some DPA d:fine headsets. The stage monitor system consists of Shure PSM1000s run from the monitor S6L, with the addition of an Allen & Heath ME-U PoE system, which is connected to four ME-1 personal mixers, used for auxiliary musicians and for training purposes.

As is standard church installation operating procedure for Clark’s team at Diversified, the project was completed on a Sunday-to-Sunday timeline. “We try to shoot for rehearsals on either Friday or Saturday,” Clark explained. “So, that means training on Friday, commissioning on Thursday, and the install has to be mechanically completed and tested Wednesday night.” He continued, “We came in with four riggers and nine installers, and we had all the old equipment completely uninstalled by Monday. And then, by Wednesday night, the new system was up, plugged in and ready to be tested. Consoles, wireless mics, racks, amplifiers, speakers, rigs, all brand-new wires pulled to each location…ready to go and start testing.”

The new system met all Cash’s expectations, and then some. “I feel like we could put our system up against anybody’s,” he exclaimed. “What I love about it is, if I’m walking from the front of the room up the rake into the balcony, it sounds like one speaker. You feel like you’re listening to one speaker when you’re walking a distance of 75 feet.” He added, “Most everybody has been like, ‘Did you change something? What’s going on?’ The speakers are pretty low-profile, so I don’t know if a lot of people noticed the difference physically, in what it looks like—but it sounds better.” He continued, “Some people think there are too many subs now, and I’m like, ‘That’s because, if you weren’t sitting in the center, you’ve never heard them before!’ So, that low end kind of crept up on them, and they don’t know what to do with it. So I tell them, ‘Just bounce with it!’”

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