Cathedral Sound: Echoing the Aesthetics, not the Signal

In Uncategorizedby tfwm

Turning the corner of Boulder Avenue in modern downtown Tulsa, Oklahoma, you might be surprised to encounter an enormous gothic cathedral with a classic appearance that is more commonly associated with centuries-old European churches than something you would find in the American south. Anyone with a true appreciation for this type of grand architecture would be hard pressed not to peek inside its massive wooden doors to admire the elegant sandstone and glorious stained glass windows from inside. But for the lucky 9000+ active members of the First United Methodist Church of Tulsa, opportunities to appreciate the building’s magnificent aesthetics are as regular as the weekly worship services.

A perfect example of perpendicular Tudor Gothic architecture, the traditional cruciform (cross-shaped) building features 75-foot vaulted ceilings with massive oak trusses and solid stone walls ranging in thickness from 18 inches to two feet. But even more striking are the stained glass windows surrounding the building, saturating the 1100-seat space with richly colorful daylight.

Yet the very architectural aspects that make this building aesthetically incomparable are also responsible for a few sound reinforcement challenges that the church has faced since its dedication in 1928.

“The church has an amazing sound if you’re just walking quietly by yourself. With all the hard surfaces and cavernous ceilings, it’s wonderful to hear your footsteps reverberate off the walls,” commented Minister of Worship Joseph Bias, who serves as music pastor for the church. “But as soon as you try to project a message, you wind up with sound bouncing all over the place, muddying the intelligibility with echoes and timing problems.”

The church considered many solutions over the last seven decades, but each had its own set of limitations and many would have negatively impacted the church’s beloved aesthetics. “You can’t very well mount speakers to the walls when there are stained glass windows everywhere,” explained Bias. “And we weren’t about to install acoustical tiles over the sandstone to control the echoes.”

Bias recalls his walk many a Sunday morning down the center aisle bisecting the nave (the bottom extension of the cruciform building). He would pass through three distinct zones of amplified sound with entirely different volumes on the 105-foot length of the building on the way to the chancel (the top of the cross, where the chancel is situated). In addition, the 125-foot width of the transepts (arms of the cross) posed different challenges altogether. “We’d have people on one side being blasted with sound, while on the other side people couldn’t hear a thing,” Bias said.

Another challenge was getting enough gain before feedback after the last renovation extended the chancel mic positions forward several feet in front of the main speakers at either side of the sanctuary. Meanwhile, the overhead choir mics made unintended soloists of the closest choir members, and the hanging wires were far from aesthetically pleasing.

After hearing about the Inspiration Technology conference held in Cincinnati (2003), the church’s Senior Minister, Dr. R. Wade Paschal, media director Miguel Figueredo, and a research committee went there to explore new ideas for solving the church’s sound reinforcement obstacles. That’s where church leaders met David Rauch of Bridge Communications, a consulting firm that helps churches identify and implement the best technology and service solutions for audio, visual, lighting, and staging concepts by bridging the communication gap between the architect and the church. “The committee consulted with a number of sound system experts who walked away completely unwilling to take on our challenges, but David Rauch actually thought he could help us, so we naturally hit it off,” said Paschal.

Rauch’s enthusiasm stemmed in part from his recent discovery of a new family of loudspeakers from EAW called the DSA Series (Digitally Steerable Array Series). DSA Series column speakers use very sophisticated digital signal processing technology and on-board amplification to allow steering of the speaker’s output pattern. Using the DSA Pilot software program, system integrators can vary the vertical coverage pattern from 15 to 120 degrees, as well as aim the coverage up or down by as much as 30 degrees. In this way, sound can be carefully directed in the vertical plane toward listeners and away from reflective surfaces.

Rauch visited Tulsa for a firsthand sense of the church’s situation, and then worked closely with Randy Whitworth of Landmark Audio to design a new audio system around the DSA speakers.

A former music minister himself, Whitworth established his audio systems design and installation firm after years of frustration with the lack of available audio installation expertise especially as it applies to churches. What’s more, since Whitworth had recently installed a new sound system for Florida’s largest United Methodist Church, in his own hometown of Lakeland, he had a pretty good sense of Bias’ particular needs.

Together, they designed the main system around the church’s existing Yamaha M3000 console. Two DSA 230s were mounted above a single DSA250 on each of the two columns flanking the chancel. Whitworth was able to steer the system’s output away from troublesome reflective surfaces like floors and walls, as well as over the top of the chancel mic positions in front of the columns to which the loudspeakers were mounted.

In order to preserve the church’s interior aesthetics, each speaker and mounting bracket was painted to match the church’s interior. The mounting brackets were modified for a more stealthy appearance while still retaining the required safety margin.

In the far front corner of each transept, an EAW MK8196 and an EAW SB150P subwoofer were installed and electronically time-aligned to the DSA arrays. This system provides side coverage in the cruciform space and additional low-frequency enhancement for the church’s more contemporary services. Additional MK8196’s were installed to provide coverage in adjacent areas such as the back third of the nave and the balcony. Audio support was also added to such areas as the chancel, the choir loft, and a small chapel behind the south transept.

Four new Galaxy Microspots in the choir loft and four EAW SM109z’s onstage replaced the older monitoring system. Amplification for all secondary audio systems is provided by three QSC CX502s, a CX902 and a CX204 while processing in these areas comes courtesy of the church’s existing Peavey Media Matrix X-Frame 88 and MM8802.

Knowing the concern for aesthetics, Whitworth did his best to make system components invisible. He installed floor pockets onstage to hide all the cables. To improve sound to the front central choir monitor, he rigged Tannoy CMS60T studio speaker components into an enclosure already camouflaged inside the chandelier over the stage-right choir loft. Two super-thin DPA Flamingo active microphone stands on either side of the choir replace the “spaghetti” of bulky mic cables suspended from the ceiling.

To fine-tune the new system, Whitworth brought in the expert assistance of Sowden and Associates’ Topper Sowden, who perfected the delays and equalization. A week later came the big test: the church’s biggest concert event of the year, held in early December 2004.

“We had three performances with more than 80 people in the choir and a 32-piece orchestra. The sound was the best we’ve ever had,” Bias said. “The clarity of the voices in the choir, the timing of the delays, the fact that the sound energy was aiming right at the people instead of the walls or the floor – it was simply outstanding.”

Just as noteworthy was the congregation’s confusion about where all this great sound was coming from. “After the first service with the new audio system, I had people asking me where the speakers were. Randy had painted them to match the paint chip I’d sent, and as a result, they were completely unnoticeable,” continued Bias. “Now, the aesthetic appeal of our building – the stained glass, the stonework, the flooring – no longer interferes with our sound reinforcement. Better still, the components are so seamless that they echo the building’s aesthetics, without reverberating the signal around the room.”

Bias concluded with perhaps the highest praise of all. “Finally, after almost eighty years, our church sounds as magnificent and glorious as it has always looked.”