How the most important part of your PA system may not actually be a part of your PA system.
Jim Kumorek · April 9, 2018
Churches with a very traditional choir and organ style of music program have additional acoustical challenges. “For traditional music, it’s generally good to have a longer reverberation time—the music sounds better in those cases,” adds Shade. “However, the longer reverberation time negatively affects speech, and is also poor for contemporary music. If we have a church that desires to have both traditional and contemporary music, a compromise has to be made in terms meeting both needs.”
For contemporary music, poor acoustics can raise different issues. “Often the music will sound loud and harsh,” says Rose. “even if it’s not actually very loud. If you can correct the acoustics problems that are causing this, you may find that you can run the system louder and not get the same complaints.”
Clearly, acoustics are something that should not be taken lightly. But what can be done to deal with acoustical issues?
Acoustics By Design
An auditorium or sanctuary can be designed to avoid the worst of the issues, and this involves engaging an acoustician early in the process.
“An acoustician is needed after the initial concept design and a general plan is made,” says Shade. “We should come in during the schematic design phase. That’s where we can identify any issues with the concept the architect has come up with.”
“The first goal is to understand the priorities,” adds Rose. “What is the style of worship? Then you start to come up with acoustical solutions. You look at the core room shaping and interior volume—does it fit the worship style? Rectangular and with more volume works well for a traditional space; for contemporary, fan shape works well for communication as it minimizes the distance to the people in the room. You want to avoid large flat back walls; curved walls are even worse as it concentrates the sound from the PA system back to the stage. One of the most common things we see now is terraced seating at the rear.
This creates better sight lines for those seated at the rear and minimizes the height of the back wall. It also adds more absorption into the room as the human body will absorb sound. Using upholstered seats helps absorb sound even when the seat is unoccupied.”
“The ceiling is a good target for controlling acoustical issues,” continues Rose. “It’s the largest plane in the auditorium. You can use it to cut down the height and reduce room volume. Its configuration can be useful to break up low frequency standing waves. And, it’s also an important element in congregational worship. If hearing the congregation worship is important, this usually comes via the ceiling. The acoustician needs to strike a balance between making the room dead for high-impact worship and allowing to have some reflection to support congregational worship and response.”