Iconic St Mark’s Church Gets Iconyx Treatment

Renkus-Heinz steerable array delivers intelligibility
while preserving unique architectural heritage

Foothill Ranch, CA | August, 2009 - For St. Mark’s Lutheran Church, a registered San Francisco landmark built in 1895, the 1989 Loma Prieta earthquake was the second major seismic event it had withstood. 15 years on from a government-mandated seismic retrofit that addressed considerable cosmetic damage the church commissioned a new sound system.

The challenge was to design a reinforcement system for the spoken word that would not interfere with the church’s traditional acoustic music presentation of pipe organ, piano, harpsichord and choir, none of which are miked.

Tom Corbett of Charles M. Salter Associates in San Francisco was the principal design consultant. "We chose the Renkus-Heinz Iconyx for two reasons," says Corbett. "First, to preserve the architectural integrity of the room, and second, we needed a very specific coverage pattern to provide uniform intelligibility over the main floor and balcony while co-existing with the natural room acoustics. The only way we could achieve that with an architecturally compatible system was with a steerable array."

Attached flat to a given wall, a steerable array utilizes a column of identical speakers with very specific spacing. Each driver has a dedicated amplifier and DSP controller chip, enabling programmable sound beams to create very specific coverage patterns. "That’s very important in a space like this," notes Corbett. "By keeping the sound away from the ceiling and off the balcony face, we created a highly intelligible vocal system without requiring architectural finishes which would affect the natural acoustics that highlight the musical presentation." To minimize visual impact in the landmark structure, the tall, slender columns were attached flat to the wall surface and custom-painted to match.

The Iconyx system in St. Mark’s consists of two IC16-R columns, each programmed to generate three distinct coverage beams per side: one for the balcony, one aimed for a long under-balcony throw, and a third to cover the front half of the church. The "R" designation means the units have RHAON (Renkus- Heinz Audio Operations Network) built in for complete remote system control over a single CAT5 cable.

The sanctuary’s physical layout presented another design challenge. "The balcony is quite close, so we mounted the two Iconyx columns higher than usual and aimed them diagonally in crossfire fashion," Corbett explains. That allows the top beam from each eight-foot column to "see" into the balcony seating while avoiding both the wood facing and the arched ceiling.

"As you know, organ designers and sound system designers are typically at odds, because they want to extend the reverberation time and make the room more musical, while for speech we want to shorten that reverberation to avoid multiple arrivals at the listeners ear," says Corbett. "But a tool like the Iconyx allows those opposing goals to coexist. In fact, for this job, we actually were able to accommodate the increase in reverberation caused by going to a full hardwood floor. Because Iconyx allows us to control loudspeaker dispersion, we can achieve excellent speech intelligibility while still taking full advantage of the room acoustics."

"The steerable array columns are extremely effective," agrees St. Mark’s Gary Schilling. "We wanted a system that would give us speech intelligibility throughout the room and fit in very discreetly with the room architecture. The Renkus-Heinz Iconyx system delivered all of that for us."