May 01, 2012, by Julie M. Clark
Church sanctuaries are often aesthetically beautiful spaces. Church sanctuaries are often acoustically challenging spaces. Navigating between these two extremes is the sound system designer.
It’s a path recently tread by Rod Andrewson and the team at CCS Presentations Systems in formulating and implementing a new sound reinforcement system at St. Barnabas on the Desert Episcopal Church in Scottsdale, AZ.
Built in 1960 under the direction of noted architectural firm of T.S. Montgomery, the 350-seat sanctuary features columns and arches, a high ceiling, and a raised circular altar with choir risers and a pipe organ located directly behind it.
“The sanctuary was originally designed to have the acoustic principles and characteristics of larger cathedrals,” explains Andrewson, who serves as chief engineer at CCS. “As a result, it’s a highly reverberant space that had been plagued with vocal intelligibility issues for decades. Over the years a number of acoustical treatments had been applied in an attempt to resolve the problem, with little to no success.”
The system project was part of a complete renovation of the sanctuary that was spurred by the donation of a new organ, with an overall goal of returning the room to its original form. As a result, church leadership wanted worship services to feature organ music, but they also wanted a system to deliver dramatically improved vocal intelligibility.
An added caveat was that all acoustic treatments would be removed during the renovation with the intent of making the room as reverberant as possible to further enhance the organ music. The sanctuary has a single level of seating in an area measuring roughly 60 feet wide by 100 feet deep under a ceiling that reaches 20 feet.
The sanctuary is designed to have the reverberant of a much larger space, with main loudspeakers barely visible on columns at far left and right. (click to enlarge)
CCS, also based in Scottsdale, was one of a handful of firms invited to submit a bid on the project. “When we were told that the sanctuary would be stripped of
all acoustic treatments, I felt like we had a real challenge on our hands,” Andrewson notes. “As a matter of fact I contemplated not having anything to do with the project at all. But before walking away, I
wanted to do a little research.”
He had successfully implemented Tannoy Qflex digitally steerable arrays in other applications, and thought they might provide a solution in this application. The straightforward goal was focusing as much sonic energy on the audience as possible while keeping it off of the bountiful reflective surfaces.
Qflex also has the added advantage of a slim profile, and the cabinets and grills can be painted, helping ease concerns about aesthetics. The CCS team arranged a demonstration of a Qflex array within the sanctuary, and the client came away impressed.
“We showed them that we could very precisely divine and steer the acoustical imprint on the audience,” Andrewson explains. “When we demonstrated the Qflex loudspeakers and VNET software to our client, it was very clear that none of our competition had even considered doing the same. I think that demo was, hands down, what won us the job.”
The system design is led by two Qflex 40 self-powered loudspeakers mounted on left and right columns about 20 feet in front of the altar, the best option available to covering the majority of seats. Each loudspeaker, measuring 83 inches high by just seven inches wide, is loaded with eight 4-inch LF drivers, sixteen 3-inch LF drivers and sixteen 1-inch HF drivers. Every driver has its own discrete amplification channel.
A key part of the equation is VNET, Tannoy’s proprietary digital processing and network protocol, hosted on a PC located in the system’s rack room which can be found behind the back wall of the sanctuary. VNET is linked to the loudspeakers via a VNET USB and RS232 interface.
With VNET, both main loudspeakers are acoustically profiled and individually optimized, taking into account their exact positions within the venue relative to the room boundary and acoustic properties of the room. A control panel allows VNET parameters to be viewed and adjusted, including overall system status as well as specific component performance parameters, while the control area provides access for adjustment of all loudspeaker DSP parameters including crossover/delay, EQ, gain and power.
While the Qflex/VNET tandem handles the vast majority of coverage needs, there are still a couple of regions requiring support. Tannoy Di5 compact loudspeakers are discretely mounted left and right (and also painted to match) to provide coverage to the narthex in the very front area.
Two more Di5s, also column mounted, are utilized to extend coverage to the choir, which is located behind the pulpit, with one more for the pulpit for “preview and confidence” (a.k.a. monitoring). These loudspeakers are driven by eight speakers in three zones, two in the narthex, four at the pulpit and two for the choir.
QSC Audio ISA-280 amplifiers in the rack room, joined by a Biamp AudiaFlex, provides processing and delay for the support loudspeakers as well as overall system control and touring. Settings are locked down so they can’t be changed, except volume levels.
Vocal reinforcement is provided by Shure wireless transmitters outfitted with Countryman lavalier microphones.Six Shure ULXP receivers are rack mounted in the rack room to support the handheld and body worn transmitters. Both podiums are equipped with Clockaudio microphones.
A closer look at one of the Tannoy Qflex loudspeakers with slim profile concealing 40 transducers that have individual power and processing. (click to enlarge)
With the system largely devoted to spoken word reinforcement, there’s also no need for a mixing console. Audio levels can be adjusted via a wireless remote that interfaces with the AudioFlex platform, and this remote also works with the Crestron-controlled lighting system (also installed by CCS).
The rack room is also home to a plethora of video streaming gear. There are two additional buildings on the church campus that are utilized for other styles of worship, and via a NewTek TriCaster Studio and three Vaddio high definition pan tilt zoom cameras, can transmit video streams (via Ethernet) of the services to use within their worship program or to home bound parishioners.
The TriCaster is equipped with an offset tool that allows for a 6-minute delay, enough time for the A/V tech to optimize the audio via a Mackie 802- VLZ3 8-channel mixer and caption the
video with TriCaster’s video effects prior to distribution. Services are also made available for download via the Internet.
“Meeting the specific aesthetic and sonic requirements of this project was paramount, but it was all under one overall goal of the client – provide the absolute best solution for everyone to receive information from a variety of media sources,” concludes Andrewson. “That’s what we sought to deliver, and the client, as well as the patrons, indicate we hit the mark.”
Julie McLean Clark is a writer and marketing consultant working who has worked in the pro audio industry for more than 15 years.