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The Scientific Foreknowledge the Bible Teaches about Church Sound?

Posted by jdbsound on July 26, 2019

Here is a fresh look at Solomon’s Temple and how it relates to Modern Churches today. Here is link to a 13 page article about church acoustics from the Bible’s point of view.
The Scientific Foreknowledge the Bible Teaches about Sound and Acoustics?

Introduction

The quality of church worship is critical to the health of a church.  The better the excellence of worship is, the stronger the church will be.  Quality of worship is not about packing the church full of people for the sake of filling a worship space so much that it becomes necessary to keep building bigger buildings.  We worship God, not buildings or pastors or knowledge.  It is the Gospel, the Bible that leads us to God.  It is God’s words that keep us in a relationship with Him.  The strength of a church is not measured in numbers in the seats or money.  Jesus taught us to feed the hungry, clothe the poor, and shelter the homeless.  The Bible teaches over and over again that we are to live by example (Psalms 1:1-6), to be a light in the world (Matt 5:16), when they see that we are different (James 2:14-26), it will be that difference that will attract people to God.

The strength of a church is measured by how people support each other, and by how much a congregation supports each other as a family first, as brothers and sisters, and then the local community.  Is the church feeding the hungry, clothing the poor, and sheltering the homeless?  The modern version of Jesus teaching for us in countries with a democracy and wealth should look like this.  Is the church cutting lawns, clearing driveways, cleaning people’s homes, fixing up members and non-members homes?  How often are church members spending time with the widows, the singles who have never had a partner, or the elderly?  Are these not the things included in what Jesus told us to do?  Are not these the same teachings in the Old Testament?  This is just a small sample of how Christianity should look like to the secular world.

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After reading the full article, please comment on it. We want to get this right as the church community needs this knowledge. If you have any questions, want to learn more or see a presentation about Solomon’s Temple and the Modern Church, contact me here – jdb@jdbsound.com

You church may be one of those that has great sound for all parts of the worship service. If it is, you should let everyone know as it will help to bring more people in. You should let us know so we can tell others. If you find this article helpful, please pass it on. Pass it on to your pastor, your friends and family. Give them the chance to learn what God can do for them today!

Thank you.

All modern churches can benefit from Biblical Acoustics
All older churches can benefit from Biblical Acoustics

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1 + 1 = 3 or When is Doubling the Power, not +3dB?

Posted by jdbsound on June 17, 2019

Here is a simple test anyone can do to determine the acoustical condition of a church.  Physics says that when the power* is doubled or when doubling the number of speakers, the sound level will increase 3dB.  This result is real when outdoors.  This outcome can be false indoors.  When it is false indoors, it is because there are acoustical problems.  Please notice that it is problems, not a problem.  When adding a second speaker failing to increase the sound 3dB, this test shows that it is never a single acoustical issue.  It is not a sound system problem.  The sound system is exposing the root problem. (If the second speaker is wired out of phase, the sound will decrease in level.)

Outdoors, sound follows the basic rules of physics.

When outdoors, if there are two loudspeaker playing with the same volume of pink noise side by side or up to 6 feet apart, and set up a test microphone or SPL meter 30 feet away. (An iPad or phone with testing software can be used if it is calibrated.) When the second speaker is turned on or off,  the sound level will change 3dB.  This result is constant in physics.  The reason this is always true is that there are no barriers around to limit the sounds from spreading out or returning from a reflection that can interfere with the direct sound.

When indoors, depending on the size of the room, often this is not true.  This failure is noticed the most with Subs and sound energy below 500 Hertz.  Doing the same test at 30 feet inside of a church, the sound level change is often 1, 1.5, or 2dB.  If the result is 3dB, there are either a lot of open windows, lots of doors that are open, the church has more than 3000 seating or the church has great acoustics. 

Indoors, sound is confronted with many other rules of physics which changes how the first rule works.

Here are the most common reasons for the sound failing to increase 3dB when doubling the power or speakers.

  • Standing waves
  • Dimensions of the room
  • Too much-stored energy in the corners
  • Too much high-frequency absorption

Standing Waves

Standing waves are excessive amounts of energy between parallel walls within a confined space.  It can often hear it.  To listen to it in a rectangle room, go between the parallels walls that are the closest together. Often it is the side walls.  Stand about 4 feet from one of the side walls.  Make a loud, sharp noise like a hand clap once.  If a person hears any rapid pinging sounds, this is a sign of standing waves.  The sound heard is often a higher range of frequencies, and they usually called flutter echoes.  Flutter echoes are a symptom of standing waves.  Bass sounds, which have longer wavelengths can’t produce the same volume of sound to hear as a flutter between parallel walls.  Whenever a person hears flutter echoes, excess bass energy present too.  This result is also true for all other room shapes when flutter echoes or flutters from a simple hand clap occur.

A second clue to standing waves is when standing at a pulpit or where a minister preaches from. With a hand clap, if the reflected sounds are coming from the side walls or behind standing waves are the cause of it.  The standing waves are preventing a large portion of the sound from reaching the other side of the room, and what is reflected back is being canceled out by the standing waves a second time which in turn prevents people from hearing the clapping returning from the back of the room. Standing waves have the effect of isolating everyone from each other in the room.  This result is also why the drummer seems to sound so loud and why most drummers strike the drums harder than they have too. It is because they can’t hear their drums at a lower level.  This outcome is also why many people comment that they can’t hear themselves when singing, and it makes them feel alone in a room full of people.

Any church with parallel walls will have standing waves if there is nothing to manage them

The reason the sound doesn’t increase 3dB when adding a second loudspeaker is because of the excess bass energy created by the standing waves in the worship space.  The excess air pressure is like putting a finger lightly on the woofer.  The excess air pressure acts as an acoustical load on the woofer, and that dampens the amount of sound coming from the loudspeaker.

Standing waves can only be removed with diffusion or some form of sound scattering. 

If people try to use absorption to fix this problem, while it will remove the flutter or in some cases, shift the flutters to a lower frequency, the untreated bass energy will make the standing wave problem more pronounced.  It will increase the feeling loneliness and discourage the congregation from singing even more.

The dimensions of the room

In churches with low ceilings or seating less than 200 people, the room is too small to be free from surface related sound inference reflections.  In a larger church space with a flat ceiling less than 16 feet high, the room will have standing waves floor to ceiling which limits the ability to increase sound 3dB with just doubling the speakers.

The reason the sound doesn’t increase 3dB when adding a second loudspeaker is that the room is limiting how much the space can support.  The excess air pressure from the extra speaker is like putting a finger lightly on the woofer.  The excess air pressure acts as an acoustical load on the woofer, and that dampens the amount of sound coming from the loudspeaker.

The only option is to diffuse all of the room if a small church.  If a low ceiling, diffusers will have to be added to the ceiling.  Acoustical tiles and drop ceilings cannot correct this issue.

Too much-stored energy in the corners

Another principal of physic is how sound is affected by boundaries.  A loudspeaker on a 10-foot pole measures 60dB.  We call that free space.  When we put the speaker on the ground, the speaker will be 6dB louder.  That is referred to as “half space.”  When we add a wall and the floor, we call that “1/4er space” and the sound increases 12dB or doubles in loudness.  When we add a second wall to the floor and create a corner, that is “1/8th space,” and the sound rises 18dB. 

Corners collect the air pressure that is created by longer wavelength sounds that accumulate on the flat surface of the wall.  With nothing to direct the sound, the sound pressure moves in all directions.  Eventually, the excess bass energy makes its way to the corners.  Depending on a lot of variables, the amount of energy that builds up is often too much.  Churches will low ceilings, large flat walls, or flat ceilings tend to have too much excess bass in the corners.  All other church shapes, except for domes have varying levels of corner issues if not managed.  Excess corn energy has a similar effect as standing waves.  When there is too much bass, it masks the highs.  This, in turn, creates hotspots and coldspots throughout the room. Hotspots and Coldspots are frequency dependent. If the sound level changes are of a narrow range of frequencies, it was most likely found them with instruments.  When a person notices them with their ears,  it means anyone with a hearing problem will miss out on some of what is being said, or what they heard and what was said was different. 

When the front of a church is in the corner, everything is either 18dB louder or 18dB quieter when compared with churches that have the front on an end wall.

The reason the sound doesn’t increase 3dB when adding a second loudspeaker is because of the excess bass energy created by the bare walls in the worship space.  The excess air pressure is like putting a finger lightly on the woofer.  The excess air pressure acts as an acoustical load on the woofer, and that dampens the amount of sound coming from the loudspeaker.

Keeping excess sound out of the corners is best done with diffusion.  It cannot be done with absorption unless the absorbers are as thick as the wavelength of the sound waves.

Too much high-frequency absorption

Sound arrives at our ears as air pressure vibrating at a rapid rate.  The faster the air vibrates, the higher the sound pitch.  The slower the sound vibrates, the lower the pitch. The vibrations are referred to as Hertz.  Sound travel at 1130 feet per second.  At 100 Hertz, a bass sound has the wavelength of just over 11.3 feet.  At 1,000 Hertz the sound waves are 1.13 feet, and at 10,000 Hertz the sound waves are 0.11 feet or 1.3 inches.  

When there is too much absorption in the room, what is left is too much bass. The excess bass masks the highs. 

For most churches, carpeted floors and padded seating is all the absorption needed. When this much absorption is add, the congregational singing is very dull and people have to be super motivated to see more that 20% of the audience singing.

The reason the sound doesn’t increase 3dB when adding a second loudspeaker is because of the excess bass energy created by too much absorption.  The excess air pressure is like putting a finger lightly on the woofer.  The excess air pressure acts as an acoustical load on the woofer, and that dampens the amount of sound coming from the loudspeaker.

The fix for such a problem is by removing the right amount of absorption panels and replace them with diffusers.  Then complete the room by adding more diffusion throughout the sanctuary to correct the frequency response of the room.

These four issues are never a singular issue.  They are often in combinations or can include all four.  Along with these problems, there are often reverberation issues, echoes, excess late reflections, the poor frequency response of the room, and other room problems that have little to do with this simple 3dB test, but they are usually there as well.  These problems can be heard when a person learns what to listen for.  Looking at how sound system is equalized is another clue of room problems.  The issues have the result of the high numbers of the congregation not singing. (In a church with good acoustics, they will often have more than 80% of the congregation singing every they are familiar with.)

Getting two loudspeakers and doing this test is simple and easy to do.  If the sound doesn’t increase 3dB, this means that adding more subs or more speakers into a worship space will not get the expected outcome. For example.  If the goal is to increase the bass in a worship space 3dB, and sound system has only one subwoofer, do this test, If the bass increased only 1.5dB with the second box, then it will take two more speakers just to get a 3dB increase for a total of 4 boxes. Think of the cost of adding three speaker boxes and all of the related hardware required to support that.  An alternative would be to fix the room with diffusion, the gain will be 6 to 10dB of performance without doing anything to the sound system.  It would be equal to adding 8 or 16 subwoofers depending on other acoustical or architectural considerations.  

Science is amazing when appropriately used to provide real solutions. Pseudo-Science or fake data is often used under the disguise of science and can be used to lead churches to false conclusions.  Many experts in audio and acoustics who see the same data, know these problems are present.  If they are not being addressed, it is because they lack the experience in knowing how to solves such issues.  If a person has done this test and the sound system provider or acoustical expert is not addressing these issue, they are not qualified for correcting sound problems in a church.  It’s like asking a Doctor who specializes in kidney problems to do Brain Surgery. What is needed a Brain Surgeon who knows how to fix both the acoustics and to design a proper sound system.

Get the church correctly evaluated before investing in that next sound system.  It can save those responsible a lot of disappointments down the road.  Fixing a room can cost less than replacing a sound system, or it could mean reducing the size of the suggested new sound system.

* Doubling the power required calibrated volume controls or switches to set up correctly as a viable test.

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The Best Worship Experiences

Posted by jdbsound on March 25, 2019

What would you prefer? A church were you can have the best worship experience or a church that looks amazing?

The organist of this church pulled every stop, pushed the peddles all the way down and the he had trouble hearing the organ just 20 feet away. At the back of the church at the sound booth, the organ was barely audible. I used a SPL meter, put it about 3 feet over my head at the back of the church and the congregational singing peaked at 105dB several time during a familiar hymn. There was no one behind us. There have been other times at other church where I designed or upgraded their acoustics were the congregation is singing acapella and they were peaking at 106dB. The good news is, singing like that doesn’t hurt your hearing.

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Acoustics are like an Onion

Posted by jdbsound on March 2, 2019

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Churches are Tools

Posted by jdbsound on February 18, 2019

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Church Sound and the Gospel

Posted by jdbsound on January 28, 2019

The goal of any worship space and the church sound system is not about loudness, gain before feedback, intelligibility, special sound effects for the organ or choir, having the most talented performers in the worship team, how many wireless mics, number of channels the mixer has or the name brand of equipment you have. The goal of a church worship space and the sound system is to be a safe place where the Gospel can be presented clearly and with little to no blemishes. Where every person within the worship space can hear and understand the Gospel as clearly as when having a conversation with someone only 4 feet away and sharing the Gospel. Anything less than that goal means that the spoken word can be corrupted in the journey between the minister’s mouth and ears of all those who are listening. The Gospel needs to be broadcasted and understood as clearly as reading God’s written words.

If your church has hot spots, dead spots, good sound in these seats and poor sound in those seats, then the Gospel is not being presented equally to everyone. If your sound system has technical problems during worship often, then it is a distraction, and it can make the difference of understanding something important.

The chart below shows tangible results when your worship and sound system are tested. There should be three tests.

The first is with a test speaker. It is a point source speaker that is small enough to mimic a person’s voice.

The next test is feeding a signal directly into the sound system and test those results. This test is just about the playback quality of your sound system.

The third test is to use the test speaker 30 inches from an open microphone such as a pulpit or any microphone on a stand and test the combined results of the worship space’s acoustics direct interaction of the sound system and open mics. You can also do a second version of this test and place the test speaker 4 inches from a microphone where the microphone is 45 degrees off axis.

If all three tests are not in the Yellow section, the results will let you know if it is your sound system, the acoustics or all of the above.  This is also a better indication predicting if upgrading your sound system will improve the results you are looking for. This is also a strong indicator that your worship space needs some kind of an acoustical management system

sti alcons chart conversion

You can get your church tested. It doesn’t cost much, and the results can save a life or many lives, depending on your point of view. As an independent consulting company, we offer church testing and results with no obligation to use our services in the future.

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Church Ceiling Height Chart

Posted by jdbsound on December 26, 2018

There are three key parts to what happens in church worship.  There is the spoken word, there is collaborative/congregational singing, and there is performance singing.  For a worship space to support these three events where speech is first, then congregational singing and performance singing, you need a specific design and dimensions to support these functions well.  High-quality speech should not come at the expense of the music.  Music should not come at the cost of speech.  There is a balance and part of that balance is to have enough ceiling height to support both speech and music in a contained space. 

Unfortunately, churches these days are building lower and lower ceilings in their worship spaces.  A person can assume that when so many churches have experienced only poor quality acoustics, many wonder what is the point of building a taller worship space. 

When a church builds a low ceiling, it limits congregational singing and it makes you more dependent on technology, but guess what!  The same things that limit congregational singing are what also limits the performance of the technology we affectionately call the sound systems.  So, instead of getting 100% out of your high quality, expensive sound system, you’re getting only 40 to 60% of the sound systems true performance abilities.  It is actually cheaper to build higher than the added cost of un-needed audio technology to make up the difference.   The chart below should clear the air as to the minimum height your next church should be. If you can afford to build higher, do it.  Also, a taller worship space does not mean being stuck with longer reverb times. A higher ceiling means natural room reverberation can be adjustable, and is tune-able.  With a taller ceiling, you can change the frequency response of the whole room without needing a sound system or equalizer.

Minimum Church Ceiling height Chart.JPG

Church height is important for a worship space.  One of the biggest parts of worship is singing.  Congregational singing to be specific.  When singing as a group, several elements are required for a good and healthy worship experience.  There is chorusing, harmony, sound volume or loudness of the singing and being able to hear yourself as well as the people around you.  When all of these elements are in balance, the worship experience is like no other.  The majority of people get a lot of satisfaction from the singing experience during worshiping in rooms that have ceiling heights that match the size of the seating capacity of the worship space. The above chart are minimum interior ceiling heights.  If you want to build higher, you can as the singing experience gets even better.

High ceilings allow for better sound system performance with less expensive sound equipment. (A lot of pro audio contractors, installers and equipment manufacturer don’t like hearing this.)  Higher ceiling permits better gain before feedback and it becomes easier to isolate drums and floor monitor. The performance of the sound system is much better too when that is coupled with a good quality acoustical management system.

There are economic advantages too.  The higher the ceiling, the cheaper it is to heat and cool when using a vertical displacement HVAC type system which is specifically designed for large gathering spaces for people.  Such systems cost less to install, they use smaller HVAC components and cost about 30 to 40% less to operate.  In addition, the cooling systems last 2 to 3 times longer before needing to be replaced. In a way, building higher cost less both in cost and in operation over time.

Another thing to consider. If building new, don’t build a flat ceiling that is parallel to the floor. (and it doesn’t count of you put in a sloping floor.)  Many churches that are moving into commercial buildings are learning the hard way that flat ceilings limit the quality of live musical performances and congregational singing.  Sure, there are acoustical panels that can slightly improve the room for amplified sound, but the cost doesn’t justify the returns.  There is little that can help congregational singing even if you have the height. Vertical standing waves are harder to manage than a horizontal standing wave. If you know what you are doing, horizontal standing waves can be controlled to create an outstanding room.  It is part of the formula for that perfect worship space.  Funny though, most concert musicians that perform in a church that I have fixed, they often make comments like, “I wish our concert hall sounded and performed as well.”  That is almost like saying, “concert halls make for lousy worship space but worship spaces can perform better than a concert hall.”

*Note* In most countries that have freedom of religion laws, the worship space portion of a church building has no roof heights limits regardless of local city building height restrictions. 

**Note** The data is based on 1200 churches from around the world. 

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What will give you the biggest bang for the buck in upgrading the Sound of your church?

Posted by jdbsound on May 2, 2018

This 300 seat church already had a reasonable high-quality sound system.  It was properly designed for the room and professionally installed. The acoustics were not that bad.  At least it was thought that the acoustics were not such a problem.  The outstanding issues they were trying to solve or improve were:

  1. Gain before feedback,
  2. Elimination of the few deadspots that were not solved from the previous sound system when the current new JBL speakers were installed
  3. Reduce sound spill from floor monitors,
  4. Better control of the drums (when using acoustic drums) and
  5. They wanted 3dB more bass from the Sub-woofer.

These are all reasonable reasons to upgrade the sound system.

Good Speaker System setup_s

The church was considered the following upgrades.

  1. Replacing the professionally designed and installed 12-year-old JBL sound system.
  2. They considered going for IEM (in-ear monitor) system for up to 8 people. (This would have included a new digital mixer)
  3. The church considered making an air-conditioned drum booth or get an electronic drum kit.
  4. They also wanted to add a second twin 15-inch sub-woofer.
  5. Estimated total cost, almost $26,000.00 installed.

This is what the church actually did. They changed the acoustics of the room.  They installed an acoustical Tube Radiator system.

What did they gain by doing this?

  1. The sonic quality of the existing JBL speaker system was greatly improved. The improvement was noticeable better regardless of how much equalization was added or when the EQ was bypassed. (Definite proof that the acoustics of the room changed the performance of the speaker system from the day they were installed.)
  2. All of the remaining deadspots were now gone. (This was never a speaker system problem as the right speaker system design was already installed.)
  3. The performance of the speaker system was such that picking up a person’s voice went from 12 inches to 35 inches with a Shure SM58 mic before feedback would show up. (Again, acoustics limits the performance of all sound system. Sure there are some very expensive gadgets that can improve gain before feedback, but such gadget can cost more than the material cost of the acoustical fix.)
  4. The floor monitors are now well behaved. No matter how loud the floor monitors get, you definitely need to and to add the front of house to hear clear sound. As it turns out, the overall stage mix dropped around 10dB without the performers even noticing as they were now able to hear the stage mix from the monitors so well at a lower volume. You could say that the monitor spill issue is eliminated.
  5. This eliminated the need for IEM’s.
  6. Since the drummer can hear himself now, he gradually started playing quieter after a few weeks. The need for a drum cage disappeared.
  7. The Single Sub-Woofer was now able to play 9dB louder without distortion. It would have taken 3 more sub-woofers to get the same loudness without distortion. That was equal to spending around $15,000.00. (Standing waves and bass buildup in the corners added air pressure onto the surface of the cones of the subs drivers. This added air pressure creates distortion. When the subs distort, the sound quality and maximum sound levels of what the sub is supposed to be able to do, can drop up to 15dB in many rooms.)

Aylmer EMC Church Pano 2017_ss

Other improvements

Congregation Singing.

  1. The participation of people singing went up from 30% to 75%. (When people can hear themselves and the other people around them, it encourages people to sing more.)  s a resulting, the congregation is singing 8 to 15dB louder. (The more people singing, the louder they will become.)
  2. No more distortion from the speaker system with playing louder which means the perception of loudness is greatly reduced. (Standing waves and bass buildup in the corners added air pressure onto the surface of the cones of the bass driver of full range speakers. This added air pressure creates distortion. When the bass drivers distort, the sound quality and maximum sound levels of what the full range speaker is supposed to be able to do, can drop up to 15dB in many rooms.)
  3. After two years, the congregation is starting to add harmonies to their singing. (That is what happens when people can hear each other.)
  4. Now when people stand up to give testimonies or prayer requests, people can hear them whenever they forget to use hand-held wireless audience microphone.
  5. The front of house stage mix is so much better. Now you can hear all of the performers without having to blast the sound system. (A well-diffused room can make the signal to noise ratio improve from 3dB to 25dB. As the signal to noise improves, the easier it is to settle into a high quality.)
  6. The worship space is now concert quality for any high SPL event, recitals, choirs or orchestral events.

The total cost of the acoustical system including painting the whole sanctuary. $1,400.00
Since this as a DIY project, the money saved went towards a better headset mic for the pastor and the new digital mixer. Total upgrade, $5,000.00. If the church contract out the installation of the Sono Tubes, add $5,200.00. That is still 60% of the cost of upgrading a perfectly good sound system if everything is contracted out or an 83% difference.

Conclusion

One can honestly say that fixing the acoustics had a far better return on investment versus just upgrading the speaker system alone. Upgrading the speaker system can never make the room sound better, improve congregational singing and it would have not been possible to delete the deadspots without adding more speakers on delays around the room. This transformation is typical of the new worship experience when a church gets the acoustics they are supposed to have. In the battle between acoustics vs sound systems, acoustics always wins. It’s Physics. Try moving a wall with air? You can’t. Change the wall and hear what happens!

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Dead Spots – Sound System or Acoustics?

Posted by jdbsound on April 9, 2018

An unwelcomed guest in any church is Mr. Deadspots. Unfortunately, deadspots in churches are more common than you think. There are two main types of deadspots. Some are frequency related/comb filtering interference and others are dips in sound levels greater that 6dB created by the room.

It is common to see frequency related deadspots in Left/Right sound system regardless if they are Line Arrays or point and shoot speakers. These deadspots are created by interference patterns in a mono speech system as a persons voice is always mono.  These deadspots are where you shift from one foot to another and notice a sound change. In these cases it becomes a problem when on one foot you hear the highs but not the lows. When you shift your position onto the other foot, you hear the lows and the highs disappear. People with hearing aids or early stages of hearing lose notice this the most. People with good hearing notice the change too but learn quickly to put up with it. Some young people think of it as a passive noise filter. If the music is too bright, stand to one side of your seating position. If the music is too boomy, shift to the other side of your seating position. Really! Isn’t that like buying a headset and controlling the sound changes with what angle you tilt your head. It might sound like a great idea until you find yourself with a lot of neck pain. No thank you.

Sound level dips are usually acoustically related. These are created with standing waves, bass building up, hollow walls, room corners, and parallel surfaces that include walls, ceilings and floors and concaved surfaces. In all of these cases, often mid and bass energy build up and the highs are absorbed with carpets, padded pews and people. By the nature of churches and how they are used, carpeted floors and padded seating often represents how the church sounds when it is 50% full. That means that if your attendance is often over 50%, the effects of padded seating and carpeted floors has little to no impact. If church attendance is often over 70% a carpeted floor makes the room more intimate during times of prayer and solemn reverence. In the end, carpets and padded seating is a good thing.

However, because of people in the room, once that room attendance is above 50% the people absorb enough highs that extra mids and bass energy is left behind as is being amplified between parallel surfaces. This excess energy automatically masks the highs. When the highs are masked, speech and music intelligibility drops. The kicker is, if you go around the room with a sound level meter, often the sound levels don’t drop much, even when you stand in a spot where the highs (when you measure just the highs) drop off over 6dB. That is because the excess bass energy is so strong that it fools the sound meter as the meter is reading an average sound level. When you take sound level readings by frequency, then you notice the high number of deadspots in the room. Get a tone generator in a cell phone or computer app and play a constant tone at 55dB at 500 Hertz, 1000 Hertz and 3000 Hertz and then start walking around. At 500 Hertz you shouldn’t notice much of change until you get close to walls. At 1000 Hertz you will notice more changes. At 3000 Hertz, if you are hearing a lot of changes, imagine what 25% of your church audience is experiencing.

Here is a church that had both acoustical and sound system created deadspots, with a central cluster. By nature of a central cluster, in a good room, it gives the best coverage and performance for speech. There is no better way to design a church sound system unless your ceiling is less than 14 ft. high. Choice of speakers, coverage patterns and speaker placement impacts sound too but these are mainly tone qualities and gain before feedback related. It may have up to a 2 or 3% impact on overall intelligibility as well.

corner view pano Ebeneezer Church_s

In this church example, it already has a fairly good quality speaker system in the ideal location for the room. It is designed as a central cluster and by nature, in this setup, it should perform well. However, it didn’t matter if you used the main speaker system or used portable speakers on stands, with any sound amplified you could find deadspots all over the room. On top of that, if you raised your voice in the room, once you were more than 18 feet from someone, understand what was being said was difficult to impossible depending on dictions of the person talking and how good is one’s hearing. When the proper acoustical fix was applied, all of those problems went away and the church didn’t need to upgrade the speaker system.

The church decided to leave the sound system alone as the gain before feedback improved and all of the deadspots disappeared. Since this is a traditional church that has no intentions to do anything contemporary, the acoustical fix was designed to not change the overall reverb time. Before and after reverb time remained about the same. 1.7 seconds.  It was the frequency response of the room that saw a major change. As the graphs shows below, where the mixer for the worship space was located, it was also one of many spots where weird measurements were recorded before. We found dozens of spots where the room measurements went squirrely. This is typical of the results of measuring a Left/Right speaker system, not a cluster system. These weird results were a result of room acoustics and not the sound system.  We used our own test speaker for all room testing.

Sound Booth Before and After

After checking our test equipment for errors, it was then realized that by just moving the mic over a few inches, you would get a very different result. In some places, the sound was perfectly fine but move over a few inches and it was not. Our ears are about 8 inches apart. In one row of seating, the largest distance we could move the test mic between a good spot and bad spot was 14 inches. Pew seating is 18 inches.  Every seating position had both good and bad sound. What we were measuring was sound masking in the mids and lows.  The energy was so strong that it masked the highs.  Not only that but the highs were most likely also being canceled from nearby wall reflection between 1800 to 5000 Hertz.  It gave the impression that there was something wrong with the sound system.

In this church, people marked their seating positions by placing personal pillows in spots where the sound was better. Sure enough, testing these spots showed better sound before the acoustical treatment was applied. After the acoustical system was installed, the sound was the same no matter where you sat including the sound booth.

Deadspots in churches are more often a result of worship space design and not a result of sound system design (unless you have the wrong speaker system design for your room). When a church replaces a well-designed sound within 10 years, and have little to no overall improvement after an upgrade, that should be a BIG RED FLAG that you most likely have a serious acoustical problem and no amount of money spent on the sound system can make those problems go away. Besides, these days, acoustical fixes cost less than sound system fixes. As a caveat, our experience has been this. Churches that have fixed their acoustics and then wanted on to expand their music programs, they were able to upscale their sound system with a much higher budget as they upgraded, it actually lead to better performance rather than an exchange of one set of problems for another.

Bottom line is, get your church properly tested. Have someone who knows how to properly diagnose the data, and then design your church a proper acoustical management system. Install the acoustical system and watch the congregation respond and grow. Don’t be surprised if other churches want to use your church for musical and recording events. Your property value may go up too.

Note – The acoustical system is made up of 8 and 12 inch half round plaster covered foam diffusers on 3 walls.  The side walls use a gradient pattern to maximize room performance. On the back wall there are 24 units of 7 ft. x 2 ft. x 18 inch plaster covered foam diffusers that are hollow which allows for additional passive room equalizing in the near future. Project completed by church members.

By Joseph De Buglio
JdB Sound Acoustics

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Where are the Carboard Tubes

Posted by jdbsound on August 28, 2017

Churches use a lot of Cardboard Tubes in acoustical room fixes because they are very effective in getting the room performance they want and need.  Cardboard Tube not only outperform all other acoustical products in churches but they are also the most affordable.  There is nothing that can do what half-round tubes can do, even at 40 times the cost.

Ok then, what if you don’t like the look of cardboard tubes around your worship space.  Here is an option some churches have been willing to spend a little extra for.

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These look like standard 5 inch deep absorbing panels.  They are not.  These are Sono Tubes mounted in a wooden frame and covered with cloth.

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The cloth was an added expense and it was worth it.  The fire rated cloth is expensive and before covering the panels, you want to make sure the acoustical system is going to work and work it did.  The church is very happy with the results and they are enjoying the room.

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This is what the installation looked like before it was covered.  The wooden frame has no effect on the performance of the half round tubes.  The cloth only affects frequencies above 10,000 Hertz which means they have no effect on speech or music.  In this installation, three sizes of tubes were used.

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At the bottom is a huge video wall screen.  On the wall are the Sono Tubes.  Yes, the tubes will work behind a vinyl screen.  If you notice the pattern of the diffusers on the wall. that pattern was needed to control lower mids and bass sound energy.  This pattern was pretested in our test room.

northside church video wall

Here is the finished installation of the video system.  It takes three projectors for each screen.  The center screen is a video wall.

Photos courtesy of Frederic Lachance of Northside Church in Coquitlam BC, 2017.

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Romanian Church gets Excellent Acoustics and Reviewed by Professional Sound Magazine Article

Posted by jdbsound on August 6, 2016

Churches don’t often get Reviews for their Acoustics and Sound System.  Kevin Young did such a review of one of my projects.  The installation company was CS Acoustics from New Hamburg, Ontario.  Here is the full Professional Sound Magazine Article about the Romanian Pentecostal Church in Kitchener, Ontario Canada.  Please leave any comments or questions below.

Should you have a chance, when your in the area, visit this church.  The people there will give you a tour. Better yet, go to a worship service.  it is different, but worth the experience.  Kevin Young is a Toronto based musician and freelance writer.

Joseph De Buglio

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Can Acoustical Spreadsheets Save Your Church Acoustics?

Posted by jdbsound on June 20, 2016

There are dozens of acoustical spreadsheets that come with the promise of a viable acoustical fix.  Some sheets are for studios and some are for home theatres.  There are also other spreadsheets for larger rooms.  As rooms get larger, (as in Christian Churches and worship centers) those spreadsheets become less accurate.  Sure, the better spreadsheets adds more variable to compensate for the limitations, but the limitations are still there. Furthermore, with all of the spreadsheets, you have to add an additional line to include a fudge factor.  In some spreadsheets you need to add multiple fudge factor lines.

When a person tries to use an acoustical spreadsheet, they are only looking at one parameter of the rooms acoustics.  You are only looking at “time.”  The problem is, for churches, and I MEAN ALL ROOMS WHERE MORE THAN 150 PEOPLE GATHER TO WORSHIP – there are other parameters that are equally or more important than “time.” Acoustical problems always come in layers.  The minimum number of layers of acoustical sound management in a worship space is 4 layers.  As a worship space becomes larger, the more layers you have to attend to.  “Time” becomes only a fraction of the real acoustical problems you are faced with.  Obviously you can’t see them but you can measure them if you are trained to recognize when you hear them.

Romanian Church Kitchener Ontario Pano 1.jpgThe problem with spreadsheets is that they are not looking issues such as standing waves – and every church – regardless of shape has standing waves (unless the space is acoustically managed in the first place which also means this article is not for you.)  Spreadsheets are not looking at excessive noise from early and late reflections.  They are not looking at bass buildup often found in the corners of a room.  They are not looking at flutter echoes and full syllable echoes.  These are all sound effects than can’t be dialed out with equalizers, delays, algorithms and the next miracle digital gadget or software. (Yet that is how most sound system designers try to deal with room acoustics.)

Regardless of a persons acoustical training, knowledge or experience,  a spreadsheet cannot tell you when standing waves are masking flutter echoes.  A spreadsheet cannot tell you when bass build up is masking a standing wave issue.  A spreadsheet can’t tell you how much the early and later reflections are reducing music and speech intelligibility. 

All that a spreadsheet can tell you is how much “time” it takes for a sound to decay in a room either as an average number.  Some spreadsheets are much more detailed and they have been written as an attempt to calculate a room in octaves or by 1/3rd octaves.  If it was only that easy.  Measuring and calculating time is just a sliver of the acoustical signature of a space people worship in. 

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It takes a lot of training to learn Church acoustics.  The same applies to Studio Acoustics, Recital Halls, Concert halls and lecture halls.  All of these rooms have specific acoustical needs and they all require a unique set of skills to properly fix them.   

What makes a church so complicated is in how a church is used.  When a church is designed as a “church,” it becomes the most multipurpose space there is because of all the ways a worship space is used.  When you say you want the worship space to be more “Multi-Purpose” or more flexible in it use, you are actually limiting what a basic worship space is supposed to be able to do. 

At the end of the day, an acoustical spreadsheet is only a small snapshot into church acoustics.  It can’t help with congregational singing, it can’t help with a noisy stage for a praise and worship team or choir and it can’t help with drum issues or speech intelligibility. 

What often happens is with the spreadsheet, it will guide you to a solution that is based on absorption.  When an acoustical fix is based around absorption, you wind up “killing” the room for all music – especially contemporary music and congregational singing – and the masking effects of the other acoustical issues get worse.  Sure, the room sounds more tame than it was before, but the ability to understand speech is either no better than before or it has gotten worse.  Before you know it, everyone gets in ear monitors and all of the members of the worship team have to sign an insurance liability waver stating that they will not sue the church for any future health problems with hearing loss.  Seriously, is that the kind of acoustical fix you want? 

Front view of creekside church_edited-1.jpgThat is what you get when you turn to an acoustical solution based only on spreadsheet calculations.  To top it all off, the results are not much better when using computer simulation software programs.  Simulation programs only show you the results at one frequency at a time.  The computer generated image may be 3D but the patterns they show are only one frequency at a time – even when it is averaged out.  To see large room acoustics in a simulation, you need to be able to see the results in 4D.  Hologram can’t show you 4D images.  That ability hasn’t been invented yet.  You need to be able to see sound in 4 dimensions because all sounds are complex.  Every sound made on earth is a combination of wave lengths that are generated at the same time. Some parts of a sound are measured in feet and some in inches.  There is no way to visually see 100 Hertz, which is 11 ft long, and 4000 Hertz which is 3.5 inches long, at the same time in the same place yet in real life, that is what is happening with sound.  We all take sound for granted but the complexity of sound is extensive.

But doesn’t sound follow the rules of fluid dynamic and other laws of physics?  Of course it does, but only when you examine one frequency at a time and that frequency is never a pure tone.  It is always complex.  The only place you can measure and see a pure tone is in a machine like an oscilloscope and the moment you launch that sound into the air, it becomes complex.  Just as sound is complex, so are the acoustical fixes for churches. 

jdbsound test room.jpg

This is one way to test an acoustical solution before you recommend it to a church.  Have your own testing facility.  Whatever research is done in this room, it mathematical translates perfectly when it is scaled up into a larger space.

As a mantra, remember this:  for all Christian churches, acoustical problems come in layers and whatever fix you choose, it has to address all of the layers in one step – which is possible if you want an affordable fix.  There are many tools in the Acousticians Tool Box to fix a worship space. There are diffusers, resonators, traps and other devices that can address the needs of a church’s acoustics. There are also stand-alone electronic solutions that work in certain worship spaces. You need a lot of training to know which ones you need, what combinations you need and how to use them, and the last place you want to do your training and experimenting is on your customers. 

If you are doing Church Acoustics or trying to fix your own church, don’t do it as an experiment and you know it will be an experiment the moment someone in your committee say something like, “lets try this as see what happens.”  With those words, the acoustical solution is already doomed.  Experts like myself can tell you the results the second you decide to try something and long before you apply the materials. 

History shows that after a church spends it’s money on a thing such as acoustics, it will not be able to afford to fix any mistakes for decades.  If the results makes the room worse or no better than before, then you are subjecting the church members to more sound abuse for years to come and we don’t want that.  Spreadsheets don’t fix churches, good training and expert help does. (It’s also cheaper in the end to get expert help.)

Finally,  consider this.  The internet has become a treasure trove of knowledge.  That knowledge is often presented as expert information offering sure fire solutions.  I scan the internet often to see what is out there.  There is a lot of great information and there are a lot of myths.  When you collect all of that info, it only holds a fraction of the total knowledge about church acoustics.  If we were to put a percentage on it, the internet holds about 2% of the total knowledge there is for church acoustics.  The books hold another 8% of what there is to know about church acoustics.  Church acoustics is so complicated that often, a seasoned acoustical expert like myself will have to fix one of a kind acoustical fixes often.  Those unique fixes are often not shared because others may think that the one of a kind fix would be needed in every other church that has the same problem.  You can have 10 churches with the same acoustical problem but in every one the fix has to be modified because of the other variables that have to be included.  The rest of the knowledge about church acoustics is held by experts because the church community hasn’t taken ownership of that knowledge yet and there is no system in place for churches to share their experiences in order to avoid mistakes in the future.  What is missing is the wisdom in knowing what acoustical fixes will enhance worship verse what acoustical fixes exchanges one set of problems for another set of problems. Problems which holds back and undermines the real worship experience the church leaders want you to participate in. 

All church can have great acoustics and sound.  If each church denomination or independent church were to set-up their own “Church Sound Standards” for the performance of their sound systems and worships space acoustics, churches will become the kind of places where people want to go.  Once a standard is set, every church will have a Worship everyone can enjoy and appreciate. 

Joseph De Buglio

Acoustician and Expert in Church Acoustics.

Posted in Church Acoustics, Church Sound Systems, Educational Must Read Articles | Tagged: , , , , , , , , , , , , , , , , , , , , , , , , , | Comments Off on Can Acoustical Spreadsheets Save Your Church Acoustics?

 
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