
Auralex Acoustics
When pastors, priests and congregants talk about “up there,” it’s usually a reference to things heavenly. But when AV designers and acousticians use the phrase, they’re often referring to a house of worship’s ceiling, the acoustical Achilles heel of many churches and temples. The most difficult and expensive place in most HOWs to reach and treat, due to their height, their decoration, and in many cases their architectural complexity, too, it’s one part of the sonic equation in churches that can present the most challenges for sound.
Ceiling solutions
Sam Berkow, a veteran acoustician whose SIA Acoustics firm was recently acquired by Robert Derector Associates, says the most common failing attributed to ceilings is the reverberation that finds its way down to seating areas, interfering with speech intelligibility, with the problem compounded in cathedral-type spaces, which tend to be the highest (and thus have the greatest cubic volume) and many reflective and often parallel surfaces, which exacerbate echoes. Berkow says that highly directional PA systems, which aim sound more precisely on seating areas and away from reflective walls, can help ameliorate that issue. However, imprecise aiming of those loudspeakers can actually make the issue worse, by putting more concentrated energy on those reflective surfaces, which can then be amplified further by the ceiling.
... the most common failing attributed to ceilings is the reverberation that finds its way down to seating areas, interfering with speech intelligibility....
Berkow suggests that ceilings be treated separately, using any of several types of products and techniques. For instance, acoustical plaster, which can be applied in thicknesses of up to 1.5 inches, can help absorb sonic energy reaching the ceiling. Another solution is the use of acoustically transparent material, which can be stretched across and below ceilings and that lets sound pass through but not bounce back. That type of solution is especially useful for renovation projects, since it will allow the aesthetics of the ceiling to remain visible to those below. A more complex solution would involve dropping a new ceiling to create a space between the existing and the new one — a matter of a few inches, in most cases — in which sound can slip in through purposely spaced slats and be corralled there with absorptive treatment, such as Owens Corning QuietR rotary duct liner.
“Ceilings are always a balancing act, between taking the energy out of the room for speech intelligibility purposes but keeping enough in to energize choral music,” observes Berkow, who applied some of these techniques at the Wilshire Blvd. Temple, the oldest Jewish congregation in Los Angeles. “That’s true of almost any part of a church, but especially the ceiling, because it’s usually the hardest part of the space to reach.”
Contemporary also contentious
Not all high ceilings are found in cathedrals. Nick Colleran, vice present of marketing at Acoustics First, points to combined-use spaces such as “gymnatoriums” that churches use for secondary service spaces. Those hard-surfaced ceilings can be as problematic as a cathedral’s when contemporary worship services are held in them. He suggests the use of acoustical baffles as a temporary, as-needed type of fix. “Big expanses of drywall are often the hardest types of ceiling to deal with,” he says. “Baffles are inexpensive and fairly nice-looking ways to treat that type of ceiling.”

Image courtesy of Acoustics First.
“Big expanses of drywall are often the hardest types of ceiling to deal with. Baffles are inexpensive and fairly nice-looking ways to treat that type of ceiling.” Nick Colleran, Vice President of Marketing, Acoustics First
Acoustics First consultant Cameron Girard underscores another common problem in contemporary-worship spaces: the ceiling above the stage, which takes the biggest source of sound in a worship space and injects it directly into the ceiling area. A solution for that is to create a kind of band shell around the stage using acoustical reflectors, which will channel more of the sound out into the house and thus away from the ceiling areas. He says that solution worked well when the company was helping a former Catholic seminary in Chicago be converted into a contemporary-worship church.
... another common problem in contemporary-worship spaces: the ceiling above the stage, which takes the biggest source of sound in a worship space and injects it directly into the ceiling area.
Jim DeGrandis, an engineer and acoustician at Acoustics First, warns that distributed-type sound systems, in which many ceiling-mounted speakers are used, can make the outcome worse. Many integrators look to that type of sound system to put the sound closer to the audience in hopes of avoiding reverberant reflections. However, that approach often just puts more energy closer to the ceiling. If the number of loudspeakers crosses a certain threshold based on the space’s volume, they’re just taking the typical ceiling issues and putting them closer to the ground instead of addressing them. The solution there is to zone the speakers, using delays to time-align them in larger sanctuaries. “Sometimes, we just tell them to turn off half of the speakers and see what happens,” says DeGrandis. “And very often that fixes the problem.”
If the number of loudspeakers crosses a certain threshold based on the space’s volume, they’re just taking the typical ceiling issues and putting them closer to the ground instead of addressing them.
Colleran does note one important irony, however: high ceilings that utilize three-dimensional decorations might be their own best acoustical solution, because the decorations themselves can act as diffusors, spreading the sonic energy out across the ceiling and diminishing what reaches the floor.
So the next time you gaze upwards in church, remember that there’s a lot more going on up there than meets the eye.