Merging Technology And Experience
At First Church of Christ, Scientist
By Keith Clark
Editorial Director

Implementing a successful sound reinforcement system in a traditional worship space often presents a daunting challenge. To the point, acoustical and aesthetic factors usually play the most significant role, most often because they can't - and shouldn't - be altered to accommodate modern system technology.

Yet at the same time, advancements in technology, combined with the skills of design and integration professionals, increasingly serve as the solution rather than the problem. A recent project at The First Church of Christ, Scientist, The Mother Church, highlights this point.

Completed in 1906, the Extension to the Original Mother Church on the 14-acre grounds of the world headquarters of the Church of Christ, Scientist in Boston’s Back Bay section now features an impeccable, well-executed sound system.

The sanctuary: measure it in "round feet" as opposed to square feet.

Senior Audio Engineer Robert "Sus" Susi directed the upgrade, incorporating one of the first Innova-Son Sensory Compact Live digital consoles in production with elements like Intellivox electronically aimed line array loudspeakers to meet all defined sound reinforcement goals.

The Extension combines Renaissance and Byzantine architectural concepts in a stunning, inspirational worship space. An organ built by the Aeolian-Skinner Company of Boston, one of the largest in the world, has a total of 13,290 pipes. Seating capacity is 3,000, divided amongst a main floor and seven balconies that are each about 75 ft. deep. Reflective surfaces are the rule, not the exception, and three large domes running consecutively top the massive interior space.

Hidden Control

Sus joined the church staff 14 months ago after compiling a multi-disciplined resume in sound reinforcement over the course of the past three decades. His work with live, installed and studio systems, as well as radio production experience, all proved valuable as he took a long-range approach to replacing an outdated system comprised primarily of two multi-cell horns and a 16-channel console located in the basement.

"TV production crew designed the previous system, so you can understand why the control position was in another room, because that's the way they handle their production," he says.

Robert "Sus" Susi at the Sensory Compact Live.

"But realistically, you can't hope to attain any sort of optimum sound quality when the mix engineer is trying to evaluate things with a pair of monitor speakers. You must know what the system is doing and be able to react as you're hearing it. Establishing a mix position in the house was one of my top priorities."

Vocal intelligibility at the church is crucial, with readers playing a major role in Sunday morning services, which are comprised of 15 parts. Public testimony meetings are held every Wednesday noon and evening. Yet the organ and a solo vocalist rate as co-equal on the sonic priority scale. Sus is also responsible for a broadcast mix supplied to the Christian Science radio network, which also has facilities on the grounds, and meetings and special events with additional requirements are the norm.

Boyce Nemec Designs of Norfolk, CT served as the consulting firm on the project, performing acoustical modeling that proved somewhat helpful in identifying problem areas. "I can't even tell you the exact square footage of the space, because it would be "round" footage anyway," Sus notes. "We needed to bring in loudspeakers under consideration and try them out in the space, evaluating what they would really do. I prefer this approach anyway. Boyce Nemec was great in this regard, providing a lot of counsel about the latest and greatest as it might apply to this project."

Thinking Digital

With an endorsement from the church restoration and renewal committee and the
considerable support of Broadcast Director Catherine Aitken-Smith and Manager of Multimedia Fred Telschow, Sus began work on the new system soon after coming on board. He first journeyed to the 2000 National Association of Broadcasters (NAB) show in Las Vegas to begin compiling a list of possible components, and he came upon the Sensory Compact Live console being shown in a prototype stage by Sennheiser its North American distributor.

"My only dealings with digital consoles had been with limited models, which are OK in limited roles, but they're just not very user friendly in a true live capacity," he says. "What really got me was the full processing capability on every channel, the extensive routing capability and the convenient operation of the Compact Live."

The Sensory Compact: plenty of capability within a very small footprint.

A small footprint for the new front-of-house position, to be located along the rear of the sanctuary on the main floor, was another factor. The goal was to eliminate as much outboard processing as possible to save on space, while having all of these parameters at his fingertips on the house console was definitely a big plus.

Every channel of the Sensory Compact includes gating, 4-band parametric equalization and compression/limiting, quite helpful in optimizing the vastly differing vocal signatures of readers, musical soloists and testimonials. (Compression in particular, he notes.) Any settings can be quickly copied and pasted onto any channel, providing a good basis to then further tailor individual channel mixes.

Meanwhile, all of the console's 16 matrix outputs offer 8-band fully parametric EQ with an adjustable high-pass filter, gating and compression. But a provision of up to 1.3 milliseconds of delay on each output stood out.

"I envisioned using the matrix outputs as the means for dividing up the sanctuary into several zones, each served by its own loudspeakers, where any channel could be routed to any zone and with appropriately tailored volume and delay," he explains. "This capability made a distributed system - the best approach given the difficult acoustical environment - an easily achieved solution, and again, one where I had direct control right at front of house. Certainly we could have attained something similar by going with many of the outboard DSP systems available, but they just don’t present the same accessibility and ease of use."

Channel assignment flexibility also helps with the broadcast mix, which differs substantially compared to what's in the house. The organ, in particular, is emphasized on the broadcast side, while vocal solos are subtler, incorporating touches of room ambience.

While at NAB, Sus also performed a quick sonic test. Putting on a pair of headphones and screaming into a microphone routed into the console, he was looking for mic preamp distortion common to previous digital consoles he's heard. "There wasn't all that much in terms of distortion. You could hear traces of it, and honestly, you can't change the laws of physics to prevent it completely. But they've done a good job of making it sound transparent. And the EQ, in particular, sounded very real to me, or very "British" as they say," he says.

Mic Solutions

Also at this time, he evaluated microphones for a variety of purposes, with the two front podiums used by all readers receiving top priority for new mics. One significant note is that these ornate wooden podiums couldn't be altered in any way to accommodate a more ideal mic'ing scenario.

Sus settled on Countryman ISOMAX IV, not only for sonic reasons, but also due to very good noise rejection and a complete gooseneck body - rather than one interrupted by a steel shaft - that's more flexible in terms of positioning.

ISOMAX IV’s at the podiums offer low noise rejection.

And, the cardioid pattern of the mic is directional while being wide enough to still capture differing vocal positions. (Note that the ISOMAX IV is also available with hypercardioid and omnidirectional patterns.)

The organ microphone situation still presents a challenge, currently handled by two Earthworks QTC-1 mics, flown stage left and right about 24ft. from the main organ pipes. "These are very good mics in terms of capturing the organ's sonic signature, very transparent, but we'd like to place them back at least a few more feet," he notes. "This is a structural issue, however. The mic cabling runs through light fixtures in the dome and we can't drill new holes. What we'll likely do is lower them a bit, to gain more distance from the HVAC ducts in the region, and see if the subsequent reduction in air noise and duct rumble cleans things up."

Dual Earthworks QTC-1’s flown to capture the organ are so aesthetically discrete that we’ve highlighted them here.

Several ambient mics supply feeds that are blended subtly into the house mix. These are Neumann KMR81's, which offer the added benefit of coming in a gray color that matches the church interior so they blend in.

For testimonies held every Wednesday, Sennheiser 3000 Series UHF wireless microphone systems are deployed, with a choice of handheld and lavalier transmitters. These systems do double-duty; their receivers are located in the basement equipment room and are linked to an antenna distribution system serving both rooms. They're patched into a Shure SCM-810 automixer, primarily providing gating and supplying a single channel feed to the front-of-house positions in either building.

"We've worked extensively with the automixer gating as it relates to the other wireless systems, to get just the right sensitivity," Sus explains. "You have to be cognizant of handling noise, which can inadvertently trigger the gate when you don't want it. The 3000 Series systems have the least handling noise, and then through trial and error, we've got the gating optimized."

Another Sennheiser 3000 Series system is dedicated to the solo vocalist, who is outfitted with an MKE2 lavalier microphone and beltpack transmitter. "The Sennheiser combo on the vocalist is low profile while giving her the transparency she's looking for, so it's an optimum solution," he adds.

Speech Presence

Main and distributed loudspeakers for the Extension worship space presented one of the stiffest challenges in the project, and this aspect lagged behind other facets. The issue can be directly defined as the maintenance of architectural integrity while attaining both extreme speech intelligibility and a more ambient musical presentation.

Given the flexibility of the digital console, two-pronged attack was taken. First, the speech portion of the system was addressed, with Sus and the consulting firm evaluating several choices before taking a hard look at AXYYS Intellivox product range from Duran Audio of the Netherlands. Briefly, these unique loudspeakers employ a line array concept to electronically aim and focus the sound field, with built-in DSP and power provisions working in tandem with proprietary software.

"Sound quality wasn't the issue; it was sound quantity. We had to have speech intelligibility, first and foremost. The way you can direct the output of these speakers, to change the azimuth and focus distance, was the primary attraction," Sus explains. "Plus, they are packaged in extremely low-profile cabinets, only four inches wide with a variety of height selections."

Boston Light & Sound, the installation firm on the project, procured an Intellivox model 6C from Duran Audio for live evaluation in the church. With a Genie lift, the 16-feet-tall speaker was positioned to one side of the platform. Aesthetically, it was optimum, and Sus found that he could indeed tailor the output to focus speech directly on the seating and almost completely off the surrounding granite facing.

One of the two Intellivox 6C speakers mounted at the front archway, painted to match and virtually invisible unless you walk right up to them.

Two 6C line arrays were ultimately installed, attached to each side of the archway framing the organ pipes and front platform. Painted a matching brown color, they are virtually invisible to the untrained eye. "We established the main sound lobe at about 75 feet out into the house, which provides good coverage from front to back, solid and steady," he says. "At the extreme rear of the main floor, about 110 feet out, it's only down about 8 dB, which is acceptable." Compact Intellivox model 2B speakers are mounted at each end of several of the balconies, with their internal processing also optimized on an individual basis. Compact Ramsa loudspeakers also painted to match the interior and completely processed with the house console serve the remaining balconies.

All Intellivox processing parameters included in the software can be accessed and modified at a Dell personal computer (PC) positioned next to the house console. Delay is done internally, in each loudspeaker, in the digital realm. Ditto gain structure. Supplemental processing and delay is attained with the Innova-Son console as needed.

"It's a great situation, where we have more than enough processing to attain the desired measure of control," he emphasizes. "The sonic signature is two dimensional, there's no question about it. But for speech this is fine, because control and clarity are the issues. I added a Great River stereo microphone pre-amp for the ISOMAX IV podium mics, which takes the edge off in addition to providing some needed extra gain. The result is pleasant - and present - speech intelligibility to all seven loudspeaker zones." (Two more zones providing feeds to ceiling speakers in common areas throughout the extension are also established at front of house.)

Next came the soloist's reinforcement. Solo vocals are routed via the console’s main mono output to two Eastern Acoustic Works (EAW) JF100 compact full-range loudspeakers positioned at the base of the main pipe organ structure. These are angled upwards where they fire into the surrounding archway, which then distributes a natural, ambient vocal throughout the house.

"The vocal sounds like it's coming from everywhere, which is the intent," he says. "There's no hard imaging, no real anchor to the platform."

Finishing Touches

A custom roll top wooden desk accommodates the house console and PC. It was carefully designed to match the aesthetic of the main floor pews and can be closed and secured when the system's not in use. In addition, the console is set on a platform that can be pulled closer to Sus for easier access.

To supply CD recordings of each service to the organist, solo vocalist and readers, Sus had to get creative. The small FOH footprint required the CD recorder to be rack-mounted beneath the desk, a location making it hard to see.

The Marantz CD-R, with wired remote, and other gear mounted under the roll-top desk.

"There aren't any CD burners in production with a wired remote, yet that's what was really needed given line of sight and infrared path issues," he explains. "Working with Marantz, we were able to track down their CDR-840, a wired remote unit that's been discontinued.

This is exactly what's required, where I can use the remote not only to activate recording, but confirm that it is indeed working without having to contort myself to get a look each time."

An indexed CD is prepared for one reader, while a CD with the entire service recording is the preference of the second reader. The vocal soloists and organist want the musical passages of each service only. The entire service and musical passages are edited to final product with Syntrillium Cool Edit Pro loaded on the PC at FOH, which is loaded with a 4-channel Mona sound card from Echo Audio. Final, edited recordings are transferred to an 8x CD burner built into the computer.

"Cool Edit Pro is easy to use, even for beginners. Virtually anyone can use it to get the results they want," Sus says. "And the Adaptec CD Creator program we use in the burning process is surprisingly good from a sonic standpoint. Our recordings are clean and transparent."

Night And Day

While he offers a diverse and certainly experience-based resume, Sus notes that First Church of Christ, Scientist, is his first long-term assignment with church sound. "It's a different set of rules and you're going for a different type of sound, particularly in a venue like this one," he observes. "It's total quality over quantity in terms of sound. Mixing is more subtle, and as a result, more challenging. Setup is also challenging - you're looking for just the right gain structures that keep things soft but clear."

Reflecting on the new system, he returns to the Sensory Compact Live console and its impact in applications of this type. "There are still some things that should be considered on the console, but Innova-Son has worked very hard all along to address our suggestions," he says. "They still call me on a regular basis, checking in to see if all is working OK and also looking for more suggestions. You can't ask for more than that."

"And, you also can't ask for more support than I've received from the church staff in putting together this system," he concludes. "Slowly but surely, everything is looking up. Certainly night and day in comparison to when I first walked in the door. They've worked with me on investigating options and directions, and while we weren't given a blank check on this project, we certainly received what was needed to do a quality job, as the resulting performance and functionality have proven."