Mt. Airy Temple Baptist Church
October ’05
Written by: Mike Joseph

Taming The Hard Decked Octagon

Mt. Airy Temple Baptist Church flies WorxAudio TL-V8i’s

Faced with the daunting task of taming an acoustically challenging sanctuary, Burlington, North Carolina’s Boone Audio chose an array of TrueLine V8i speakers for a highly reflective space with a history of failed sound systems. Hung with WorxAudio’s TrueAim rigging grid from a Schedule 40-rated pipe and custom glue-lam beam, the new sound system addresses all the qualities that the two previous systems lacked: point-source sound origination, high intelligibility, and wide frequency response with minimal electronic correction.

According to installer Paul Boone, the system went up quickly and easily, and importantly, it worked extremely well. “The beauty of this center cluster system was that it was fantastic right out of the box. It was flat in the room. To be honest, it was the closest “plug-and-play” PA that I’ve ever installed. We didn’t have to do anything to it.”

Boone was faced with a not uncommon situation. “The Pastor of the church said they had put two previous systems in, and this would be number three. This time they wanted it right. ‘It’s gotta be perfect,’ they told me. I said I could guarantee that they were going to be happy, and would even put it in writing. I said it would definitely surpass what they had installed previously (12 J-brand E-model enclosures), and that they’d be very happy with it. I promised. That’s why I chose the V8’s.”

Like so many church installations, being recommended for the job was a word of mouth situation. Boone had done a PA installation for another church in Burlington, and that pastor, as so many have, went to a revival at the Temple Baptist Church in Mt. Airy. Temple Baptist’s Pastor told him that they were having trouble with their sound, and when the visiting pastor tried to preach, he found that it was indeed terrible. “You need to call Paul Boone in Burlington” started the process. The church had been built ten years previously, and even with two attempts to install a good sound system, they were still having massive problems.

Continues Boone, “He described the room, and I knew it would be a challenge – an octagonal shape – with about 1500 seats. The facility has laminated beams, with wood decking on the ceiling, and I said OK, sounds like you have a lot of hard surfaces and stuff like that, and he said yah, we sure do. Then he told me the kicker, what the current PA consisted of: 12 plastic boxes on six of the beams, wrapped around three quarters of the radius of the room. Sound everywhere and no point source. Horrendous.”

As is often required, Boone invested a number of non-office hours. “He invited me to the church, and I said I’d come over and do an evaluation to look at everything. He really wanted me to come for one of their services, so I drove there that Sunday. I arrived an hour and a half early, and when I walked in, almost had to apologize to him. I was almost laughing. I knew without even hearing it that the sound had to be mush as far as sound quality. He said that this would be system number three, and that this time they wanted it right.”

Boone agreed to stay for the service. “I sat toward the back, and it was completely unintelligible. I can’t even describe to you how bad it was. Actually, not only was there a muddled repercussion of sound from all directions, but worse, when you would actually look at the pastor, the sync with his lips was off. It was like watching a Japanese Godzilla movie! The sound was actually coming from behind me. It was very chaotic. I said ‘Send me some blueprints, and we’ll plot this thing out.’ I then contacted Hugh Sarvis at WorxAudio, and we looked at this thing together in my office. We decided to spec the V8’s. And as the customer was real anxious about everything blending in to the architecture, we let them pick a custom paint color, that WorxAudio then used to finish the speakers. They’re flying up in the ceiling, in the superstructure, so you can hardly see them.”

The Main Story
With the shape of the room and hard, reflective ceilings and walls, getting smooth yet controlled coverage was the challenge. By installing six TrueLine V8i speakers on the TrueAim grid, says Boone, “We were able to aim everything with such precision that the pattern was stopping about eight feet up the wall, based on the tilt. We had a lot of wall and ceiling surface that we weren’t hitting, area that was being hit by the previous system. There’s a difference between when the church is occupied and not, but even when nobody is in there, the pattern control is so great with this system, and the throw is so accurate, that sound is not bouncing everywhere. It’s almost as if you’ve done acoustic treatment, it’s so accurate, and no acoustic treatment was done in this installation. It was amazing. I’m convinced, with these speakers.”

Boone attributes the control to the WorxAudio grid. “The grid is nice. First of all, as I like to tell everybody, there’s a science and an art to this whole thing - understanding the pattern, understanding where the sound is going. With this line array, we are providing a level of pattern control that most conventional systems can’t hit. The WorxAudio V8 array made my job a whole lot easier, in that I just dialed it in. We used six of them for the house, stacked, 140 by 60. We knew where the sound was going to go, and in fact, it just plain worked.”

One aspect of the WorxAudio TrueAim grid is that you can fine-tune a tight pattern without doing a massive rigging change, like cutting wirerope or cables, or without having to tweak motors. Says Boone, “With the way this grid is designed, we have a technician ride up on a lift. There’s an adjustment wheel, a worm gear mechanism, that makes it easy. You put your inclinometer on the grid, and every turn is a half a degree, so it’s very precise. It’s really a good design.”

In this installation, cosmetics were important, as was the structural engineering. Explains Boone, “To hang the TrueAim grid, we had to build another glue-lam to span between two of the main support beams. We mounted this one between two of the big beams, the carrier beams, and in the center we drilled a 1” hole. We then used a schedule 40-rated pipe and a rated flange mounted to the top of the beam. We probably had four inches between the piping and the decking. The true fly point is the schedule 40 pipe. We painted it the same color as the interior, and it all looks really clean. The pipe comes down and attaches to a yoke on top of the grid, and that’s threaded too, so it gets locked in. It’s solid and it’s not going anywhere. We had an engineer stamp the beam, to make sure it would hold the load. We calculated the total load to be a little over 1000 lbs, and our rule of thumb is 5 times, so the beam is stamped to hold 5,000 lbs. It’s a clean install, and it’s really attractive using the pipe, rather than having a lot of cables or wirerope. It’s a slick finish.”

Fold It Back
As an added bonus, a choir foldback V8i was hung off the back of the same grid. Boone explains, “We’ve got six V8’s in the front center cluster for the main house, and then one on the back, turned around off the same grid, for the choir. WorxAudio suggested the choir foldback speaker attached to the hanging grid, and that has worked tremendously well. That V8’s pattern is 140 degree horizontal and 10 degree vertical, which was perfect for the choir loft, which sits three or four rows up above the stage and wraps around. The coverage of that one speaker, based on the height and distance, addresses that area beautifully, like it was made for it. That was one of the highlights of the installation, because the choir has never had good audio. The throw is maybe 40 feet to the choir. A pretty deep platform.”

Continues Boone, “All of the V8’s we used are the powered versions, with built-in amplification. WorxAudio fabricated a custom bracket for the back of the grid, engineered so it would be fully adjustable. The ability to adjust the tilt on the bracket to zero it out in space is awesome! When we were testing, some of the choir members were in the loft, and they were just blown away. We received one of the true all-time accolades when they said the sound was like it was right there in your lap, right in your face. That was one of the highlights of the installation, because the choir has never had good audio. Before, they couldn’t even hear the Pastor or the music director speaking to the congregation. They’d never been able to hear themselves, either, until we installed the V8 array with the unique rear-facing speaker on a bracket.”

A little on the sides
To fill in the corners beside the platform, Boone installed Wave Series 12 AIs as sidefills. Says Boone, “We had to shade in a little by mounting two speakers by the corridors on the sides, painted white like the ceilings there, and you can hardly see them. We adjust those levels with a second amp channel, because unlike the V8’s, they are not powered. As it turns out, their sound is transparent; you don’t notice them. You don’t realize that they’re there, which is the way it’s supposed to be. We put a delay on the main cluster to line everything up in time. The fills are behind the main center cluster line array by 20 feet or so, so we brought the mains back in time to match.”

At power-up time, the system was easy to tune. Explains Boone, “There’s a common signal routed to each powered V8. Each amp in each speaker has it’s own level control, and there are internal EQ settings that can be adjusted. It’s built into the software, so for example, we rolled off a little bottom for the choir foldback, and added a little 2K. There are a lot of provisions for subtle tweaks here and there. But I’ll tell you, this is the closest to plug-and-play I’ve ever seen. Seriously. When we provided all the data to WorxAudio, they understood the room and worked the Ease program to bench it out. And when we then plugged it in, in the field, we were ready to go. I hardly had to touch anything as far as EQ was concerned. It’s is so smooth, so fluid and so even.”

Concludes Boone, “We’re already going back to some former customers, the ones that haven’t gone to a line array, and talking about upgrades. There’s an install in Greensboro that we did back in 1999, before line arrays were really around. It was a huge install for us, with over 3000 seats. We had put a more traditional speaker system in there. We’re communicating with them right now about installing WorxAudio line array boxes. As you can tell from the Mt. Airy install, these boxes are fantastic; there are just a lot of positive things about them, everything from cosmetics, to the compact enclosure, to the ease of installation using the grid system, to being able to easily and quickly get your angles correct. There are a lot of very useful tools there. It was a very positive experience at Mt. Airy Temple Baptist.”