Welcome to the world of Church Acoustics

Sound system design has nothing to do with the equipment you use. It is about the location of speakers used to broadcast into a room and the interaction of the room with the speaker system design.  It doesn’t matter if you are using line arrays or point-and-shoot speakers. If speakers are placed in the wrong position, both systems will have the same limitations.  It is all about cause and effect.  A sound engineer needs detailed knowledge, experience, and wisdom in understanding room acoustics or when to know enough to ask help from an acoustician to understand when to use which system.  Did you know that the room will tell you where the best places are to put speakers? 

The room will tell you when to use one of the following techniques:

• Distributed Sound System
• Central Cluster or single speaker system
• Left Center Right system or cluster
• Left Right System
• Live Stereo Hybrid System
• Hybrid Distributed Sound System

The geometry, reverberation, surface materials, acoustical management system, and room volume must be accounted for before creating a sound system design profile.  After all of this is done, you can start to determine the size of the sound system needed. 

If you think you need to do some acoustic treatment or the church has already been treated, it should not be using the spot treatment method, which means placing a few panels on a wall or two.  Adding something to one wall or any part of a wall affects the whole room.  This also includes the placement of screens, lighting, and other items related to multimedia.  Even room renovations change how a room sounds. It is all about cause and effect. The acoustics of a church must use a planned system that treats the whole room.

A spot fix is when enough panels are added to solve one problem.  When there is a problem in acoustics, there are always other glitches that mask other difficulties that you can’t hear and often are not shown in acoustical measurements.  Here is an example: Placing sound absorbers on a balcony’s front face will eliminate an echo.  However, the added absorption often strengthens the mids and bass, making speech and music sound muddier.   This then requires adding expensive bass traps.  While you can use aggressive equalization to improve the sound system for speech, you will need a different equalization for music.  While these efforts can somewhat help with amplified sound, as long as someone remembers to switch the EQ settings, the congregational singing is degraded until bass traps are added.  Add the bass traps.  It is all about cause and effect.

However, you may have noticed that after treating the front face of the balcony and adding the bass traps, there is now a softer echo off the back wall, or the reflections off the side walls are much worse depending on the shape of the room.  Reflections off the side walls are detected when clapping from the front of the center stage.  Those reflections from the sides or back interfere with speech and music intelligibility.  It is all about cause and effect.  Change the EQ of the sound system.  Helps with speech but doesn’t help with music at all.  Despite changes to the sound system, speech is worse in the back half of the room.  Add speakers to the back half of the room.  It helps people with good hearing and doesn’t help with hearing aids.  Add a delay to the speakers.  People with hearing aids do better, but they are still not happy because someone is sitting in their spot where they know the sound is better. 

If you apply something to the sidewalls, the echo off the back wall becomes much more pronounced and interferes with hearing on stage.  Switch to in-ear monitors.  It’s all about cause and effect.

Now the drums are too loud. Add panels to the stage or get a drum shield that costs more than fixing all of the acoustical problems in one step.  With the drum shield, the drummer plays louder because they can’t hear themselves properly.  The insides of the drum enclosures are easily overloaded, making it harder for the drummer to hear all the different drums and cymbals.  After additional dampening to the drums, the drummer played even louder, getting elbow and wrist injuries.  Sound is still bleeding through the shield, even after adding a roof to it.  Some churches have turned the drum shield into a self-contained room with air-conditioning as a permanent fixture on the stage.  It is all about cause and effect.

For the time being, congregational singing has become a chore for most, resulting in less than 20% of the audience singing.  To get people singing again, you pay singers and musicians to lead the worship and keep the talent sticking with the music entertainment program.  This helps for a while, and before long, you are back to less than 20% of the audience singing.  Bring in larger screens, add lighting effects, and use lighting to help create a mode to encourage people to sing.  Again, this helps for a while, but participation drops back to 20%.  These objects change the acoustics of the room, and everyone just puts up with the sound degradation.  It’s all about cause and effect.

In the meantime, the sound system has been replaced, and church attendance is up, but fewer people come to prayer meetings or Bible studies.  Turn to home groups.  At first, home groups bring in more people, but as the church continues to grow, more people are slipping through the system and are not included in the home groups or any spiritual support.  Fewer people are growing as there is no alternative for mid-week meetings at the church.   The preaching is dynamic; the entertainment is awesome, fewer people are actively involved in the church, and more people become adherents with no real motivation to join, become members, and learn more about their faith.  The church is full of Sunday worshipers unable to defend the Gospel, but they know and sing the choruses sung by the church all the time.  It is about being part of something free of guilt, responsibility, and not knowing what salvation is.  It’s all about cause and effect.

Wait a minute, what does any of this have to do with acoustics and sound system?  The sound system is just equipment and technology.  The room is just a set of walls, floor, and ceiling.  When empty, they do nothing.  When energized with sound, an immediate cause and effect impact every part of the worship service.  Sound affects how people react to events in a church.  Consider how people respond to movies at a theatre.  When the sound is excellent, the audience will tell you how good the picture looks.  When the sound is poor, people don’t come back.  How much more does that impact a church?  Again, it’s all about cause and effect.

Next, check the acoustical condition of your church.  Have your church properly tested for all aspects of worship, not just the sound system and hardware performance.  Test for congregational singing.  Test for audience participation for prayer and testimonies from the seating area of your church.  Check for the signal-to-noise ratio on the stage and in the audience.  Check the frequency response of the room and ignore the reverberation time if there is more than a 20dB difference in the response of the worship space.  If your worship space passes, then you don’t need any help.  Your sound system is already working perfectly.  If you have any concerns or want better performance from your sound system, fix the room.  It’s all about cause and effect.

After upgrading the sound system and worship space, start mid-week Bible Studies at the church.  The congregation will become stronger and healthier if people come to the church mid-week.  Congratulations, you have just upgraded your church’s sound to meet all a congregation’s needs.

The story you have just read happens in many churches.  It is based on the testimonies of hundreds of churches around the world.  If this doesn’t sound like your church, have your worship space tested anyway if it hasn’t ever been properly tested. The results can be a surprise or a blessing.