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Posts Tagged ‘Church sound’

Half Round Diffusers vs. Phase Gradient Diffusers

Posted by jdbsound on May 20, 2021


Many people ask how the panels will look before looking at how they perform when it comes to acoustic solutions.  Here is a short video compare two acoustic treatments that can get similar results and the cost differences without looking at the aesthetics issue. Our experience shows that most church members change their opinions on aesthetics when the acoustical fix does a great job at fixing the room. Congregation members of most churches do agree with one idea. It seems that if the acoustic system fails at improving congregational singing, the panels on the wall have to look good as wall furniture. If the acoustic treatment improves congregational singing, how the panels look doesn’t matter. The aesthetic issues disappear. If you have any questions or comments, please post them below, and we will respond to them right away.

Posted in Church Acoustics, Church Sound Systems | Tagged: , , , , , , , | 2 Comments »

The great church carpet debate!

Posted by jdbsound on April 23, 2021


Should churches have carpet in the sanctuary and should there be padded seating?

Here is our latest video on this important issue.

Here are the details of how those values came to be.

The standard for a worship space to have a signal to noise ratio of 20 to 25dB and a flat response from 80 to 8000 Hertz comes from studying worship styles and working on hundreds of Churches.  First, you have to look at all of the various elements of worship.  They include:

  • Main Elements (Based on Scriptures and by Jesus Example)
    1. Reading of Scripture
    2. Preaching and Sermons
    3. Questions and Answers
    4. Prayer
    5. Celebration of communion
    6. Congregational singing
    7. Offerings
  • Secondary Elements (items that churches have added to worship after the reformation period.)
    1. Choir or choral music
    2. Music to support congregational singing
    3. Music lead by a worship team
    4. Announcements
    5. Sharing of testimonies
    6. Sharing of prayer requests
    7. Singing performances
    8. Music performances
    9. Music Rehearsals
    10. Child participation
    11. Congregational meetings
  • Event Elements (non-worship uses of a sanctuary.)
    1. Weddings
    2. Funerals
    3. Teaching Events
    4. Conferences
    5. Concerts
    6. Fundraising events
    7. Music Lessons

These are all of the main elements of how the church sanctuary is used over its lifetime.  Not all churches will practice these elements, but the first seven elements in the main portion are universal.  Now here is an aspect that is least understood.  If you have the ideal acoustic conditions for the first seven elements, the worship space can support all of the other elements that all churches will practice at one time or another.

For the rest of the article, here is a link to the PDF file on Carpeting in Churches.

Article by Joseph De Buglio

Posted in Church Acoustics, Church Sound Systems | Tagged: , , , | Comments Off on The great church carpet debate!

How to fix Congregational Singing Acoustically in any Church

Posted by jdbsound on March 6, 2020


Congregational singing is perhaps the third most important part of worship.  Prayer and preaching of the Gospel come first and second.  In many church publications and websites, there are many articles about how to improve congregational singing.  When you say improve congregational singing, what are you truly asking for?  In almost every case, they are asking how to get more people to sing.  And the theory is, that the more people are singing, the more they will be engaged.  The means of how they attempt this is with a high power sound system and strong leadership of the lead singer in a praise band. You never hear them suggesting to fix the room.

Here are some of those titles. 

  • 7 Tips To Encourage Singing in Your Church – Gavin Adams
  • Nine Reasons People Aren’t Singing in Worship
  • 12 Things to Avoid for Better Congregational Singing
  • Fifty Ways to Guarantee Poor Congregational Singing
  • How to improve congregational singing: 4 suggestions to …
  • A Simple Way to Improve Congregational Singing: Get Rid of the Carpet

There are many more.

The ideas recommended are extraordinary, and most of the time, they are putting the bulk of the load on the church leaders, including the pastors and song leaders. This is so wrong.  The truth is, all of the recommendations outlined are the results of trying to put a square peg into a round hole.  There is a simple solution to all of this.  When you read the articles, what church leaders are doing is a direct result of compensating for poor acoustical conditions.  Choosing the right keys to sing in, choosing a better selection of songs, hiring professional singers, and performers, in the end, it only helps things slightly.  The thing is, what the audience keeps telling me is that when they are singing, they feel like they are singing alone, it creates a sense of loneliness.  People feel as if no matter how loud they were singing, their efforts have no contribution to the overall volume of the congregation.  When you can’t even hear yourself, most people just give up and don’t bother singing.  Some may just mouth the words.

Sure, there are times when we see people at a concert singing a particular song, and it sounds impressive, but the reality is, those people will not sing the whole show at that volume.  It is more about having an emotional high and nothing more.  It is doing something to capture a moment for personal gratification and bragging rights.  That is not worshiping in any sense of the word.

My take on how to get the congregation to sing is by first identifying the source of why people don’t sing in your church.  In 90% of the churches that I have helped solve their congregational singing issue, it has always been around one reason – acoustics.  Here is some background you should know.

This is a new church with diffusers built into the walls. The quality of this room is such that when this photo was taken, the congregation drowned out the Pipe Organ. The organist said he pulled all the stops and he could not hear the organ for some of the songs they sang. At one point he stopped playing. With a sound meter recorder at the pulpit, the congregation hit 105dB several times and no one complained that it was too loud.

The struggles of congregational singing started long before the sound system was invented.  It is my belief that Choirs were formed originally, because when Christians first started to worship in existing pagan temples, (after the edict of tolerance,) most likely, those temples had such poor acoustics that the congregations back then had the same problem of not hearing themselves.  Then some talented singers found that if they stood in a particular part of a room, they could hear themselves and create an awesome sound of choral singing within the pagan temple.  That talent was later included as part of the worship.  When Christians started to build churches, when the buildings were finished, they asked the better singers to go to the part of the worship space where their voices were effective in creating this big sound where a few people would sound like many.

In the end, as more and more churches were built, the choir became the focus of congregational singing, and even though the congregation was encouraged to sing, the choir was the focus, not the congregation.  This continued throughout church history in one form or another.  Sure, some large cathedrals have these amazing sound effects. (Sound effects do not support congregational singing or speech.) Still, in the end, it is the choir and the organ that dominated worship, not authentic worship singing or hearing the Gospel.

Throughout the Reformation period to today, churches have been experimenting with worship space designs to discover the Rosetta stone of church acoustics.  Churches have been trying to create a worship space without any acoustical planning.  It hasn’t happened yet that we know of and if there is a church out there that works, where is it?  Why would it be kept as a secret?    When the room helps the singing of the congregation, the congregation will sing, and they will sing as loud as they are inspired to.  The same properties that makes congregational singing work, speech will be equally as good.  Around the world if there are such churches that have the proper balance of sound, for speech and congregational singing, why has no one documented these jewels or studied them to see what makes those churches better than others.  No one has made permanent records for future churches to follow. 

It seems that when a church gets known for its musical performance quality, it usually suffers from speech, and for years people have been brainwashed into believing that you can’t have a worship space that is good for both speech and music.  That comment is true, for a musical performance space or concert hall.  This is not what a church needs. A church needs a room to support congregational singing, not musical performances. 

When I get hired to fix a church, one comment that is repeated often is, we can’t afford or don’t want a concert hall.  That is the whole point.  You don’t want a concert hall, and it would be detrimental to a church to have such a space.  Concert halls do not support congregational singing, none of them do.  Concert halls are awful for speech.  If you look at most concert halls today, when it comes to speech, they close curtains, expose absorption panels, and they rely on costly sound systems to broadcast speech events.  Concert halls are either-or spaces.  They cannot support speech and music equally.  Furthermore, they don’t support audience singing at all.  How do I know that?   When I go to most of the churches that I have fixed in the past, when the attendance is around 90%, the congregation can drown out the pipe organ, the electronic organ, and the amplified worship team.  Yes, it is possible for the congregation to drown out a sound system with professional Christian performers leading the music.  That is what good acoustics can do in a worship space.  When people try to sing like that in a concert hall, it sounds like chanting in a sporting event.  It is not very musical and singing in four part harmony is out of the question.  In a worship space, a well-motivated congregation can sing over 105dB with the sound system off when the acoustics are managed for congregational singing.  If only the sound system could perform that loud without distortion and without the congregation complaining about the loudness.

Consider this, the invention of the sound system and its introduction into churches merely ushered in over time, the ability for contemporary worship, with the goal to get more people singing.  Yes, many churches tried amplifying the choir as a means to get the congregation to sing, it didn’t work.  When it came time for speaking, the sound system failed as well to amplify speech properly without feedback – This created a dilemma.  To make the sound system perform better for speech, churches add absorptive flat panels, and that usually means killing the room, which in turn, discourages singing.  The sound system was believed to be the solution to improving worship, but the truth is, the sound system can only amplify what the room allows.  In this struggle between the sound system and church worship, no one looks at the room as being the limiting factor.  Instead, observers and people asking whomever as to what can be done, the fingers point to the technology, the pastor, the song leader, and the soundmen who get all the blame.  All of the other recommendations are meaningless until the room is fixed.

The only complaint this church has is that congregational singing is much louder up front.

As I mentioned earlier, I fix the sound in churches all over the world.  Without changing the leadership, the pastor or song leaders, and without changing how worship is conducted, with the methods I use, most congregations go from 10 to 30% of the audience singing to 65 to 90% of the audience singing when the room is fixed.  That happens because there is a way to make the room very responsive to exactly what people need to hear and feel during the singing portion of worship.  At the same time, the same system improves the quality of speech, and as a bonus, the performance of the sound system increases substantially more.  Doing church acoustics correctly, is being able to have a room that does both speech and congregational singing equally well.  It also winds up being a good room for Christian concert and drama performances.  Is it really possible to have a worship space that does everything well?  Yes.  Should you think that this is about a compromise? Think again, it is not.

The method of sound management that I have been using in churches is not of my design.  I cannot take direct credit for these successes.  I learned from an expert in Church sound.  This sound management system that is now in over 450 churches, is the same method as originated by the hand that guided the fingers of King David, who designed King Solomon’s Temple.  The acoustical system that I use is the same system that was designed by God.  As I said, I can’t take credit for the success in the churches that have this system.  Here is condensed version of how I learned about it.

Years ago, I had read or heard this verse in 1 Kings 6:29, which says that on all of the walls within and without, there were carvings of Cherubs, Palm Trees, and open flowers.  Then one day and as the pastor was reading this passage from the pulpit, it dawned on me that the palm trees seemed out of place.  They have no aesthetic value.  There is no spiritual, nor ritual reason for having palm tree carvings on the wall.  Then the acoustical knowledge I was learning at the time kicked in.  If there was no acoustical treatment within the temple, the Levite Priests would have not been able to understand each other.  That room would have been ringing well over 5 seconds.  Under those conditions, even at 24 inches, the reverberation would have made it difficult to impossible to understand speech.  It says that in the large room of the temple called the Holy Place, that the priests taught, they read the laws, they played musical instruments, they sang and prayed.  They also did rituals that would have involved speaking.  What was in the room that allowed them to do all of those activities, which are also the same actions we do in churches today?

After doing a lot of testing and experimenting, I discovered that the shape of the palm tree could be mimicked with cardboard, wood or plaster tubes which come in a range of costs, depending on how important aesthetics are and the budget your church can afford. This changes the performance of any existing church into a high-quality worship space that supports both congregational singing and speech.  Before installing any churches with cardboard tubes, we tested a number of churches.  For the first church tested with cardboard tubes, we used 10 and 12 foot long tubes, leaned them against the walls of a church and left them there for three weeks.  At the end of three weeks, not only was speech so much better, but the number of people participating in congregational singing doubled.  This was a huge surprise, and it was unexpected. We repeated this test in a dozen churches, and all of them had similar results. With those outcomes, I started recommending churches to use half-round tubes around their worship spaces, and every time as a new installation was completed, the results were almost all the same. (Let’s face it, some room shapes are better than others.)  Speech improved, and congregational singing always was much better.

In most cases, at the 6th month follow up to an installation, the contact person would tell me two things.  The first was an attendance increase.  The second was that 65 to 90% of the congregations were singing every song.  In most cases, there was no change in leadership, or order of worship or how singing was conducted.  All of the deadspots in the room were gone.  Now you could sit anywhere and sing out and feel like you are part of something big.  Sometimes I also got glowing reviews of how the sound system was fixed when nothing was done to the system except for some equalization. 

Since around 1994, over 450 churches have applied this method of managing the sound in their worship spaces.  All of them have reported similar results.  The interesting thing was, most of these churches didn’t hire me to fix their congregational singing.  They hired me to improve the performance of their sound systems.  They wanted better speech intelligibility.  The half rounds tubes are the most cost-effective solution to improving the performance of any sound system.  This method fixes the sound system much better than using any absorptive panel. 

There is also a unique feature that half-round tubes have that no other acoustical system can do.  The half-round tubes, when laid out in a specific pattern, can equalize a room.  By adjusting the spacing, the sizes, and when using prime number sequences, if there is enough wall space, you can cut up to 40dB of excess sound energy from 50 to 1200 Hertz.  If your worship space has excess energy, for example, at 400 Hertz and it feeds back there all the time, you can space the diffusers to cut out that frequency range.  No other acoustical system in the world can do that.  The most powerful acoustical system in the world comes from the Bible, and it is designed by God.  Many people say that the Bible is sufficient in all things, and this is another example of that Biblical truth.

We have to stop blaming worship leaders, song leaders, and pastors for the lack of congregational singing.  Saying things like changing the key to sing in or changing the order of music is blaming the worship leaders, and because of acoustics, all of their efforts cannot get any significant results because the room will cancel their efforts.  Song leaders are always searching high and low for answers, and if you watch them carefully, they are constantly trying new things to get the congregation to engage more.  Sure, for the short term, they might get an additional number of people singing, but after a few weeks, it goes back down to where it was before.  It’s not that people don’t want to engage; it is because the room will not allow them to participate in group singing.  This is the real reason why so many churches with contemporary worship styles have sanctuaries that are as good or better that performance clubs in Las Vegas.  So many churches have turned to an entertainment style of worship.  How un-Biblical is that!

On the internet, there are plenty of videos of young people in churches with hands up in the air and swaying to the music, but if you look closely, most of them are just mouthing the words, they are not singing.  That is not worship.  When what goes on in a sanctuary looks more like a rock concert, it is not church or worship.  It is just clean, mostly unspiritual entertainment. 

If there is any blame to go around, here is an uncomfortable truth.  When I am hired to help a church, congregation members always tell me how, for years, they have been complaining to the church elders.  Since churches are so reluctant to share their experiences about sound to other congregations, most church elders feel helpless because there are no standards for church sound and acoustics for them to turn to.  When they ask consultants for help, they say, ask 10 sound guys what to do, and you get 10 different answers.  This madness has to stop.  The Bible has the answers to church sound, and it is a solution that is superior to any other system at any cost. 

The best way to improve congregational singing is by fixing the worship space to the same standards as outlined in the Bible.  In the end, this is the only option.  If your church already has more than 65% of the audience singing, you are most likely not having an issue of the congregation being engaged in worship.  For the rest of the churches out there, seek out what God can do for you.  You don’t need an expert or acoustical consultant or sound system engineer to have a successful transformation.  Churches can do this on their own.  All you have to do is look at the examples on my website and copy whatever layout you see.  If you need more help and can afford the cost of a consultant, hire one who understands the Biblical way to solve church sound problems and congregational singing.  There is no mystery or formula or program when solving the congregational singing issue God’s way.  Congregational singing is also a spiritual issue.  It is what binds up together as believers.  Stop solving spiritual problems using mans’ ways.  God’s way always works.  Don’t take my word for it.  Trust God.

(c) By Joseph De Buglio March 2020.

Posted in Church Acoustics, Church Sound Systems, Educational Must Read Articles | Tagged: , , , , , , , , , , , , , , | 1 Comment »

What are your Church Priorities about sound when it comes to preaching the Gospel?

Posted by jdbsound on February 25, 2020


Is the performance of your worship space a priority?  Is the message always crystal clear in every seating position, and over 60% of the congregation is singing all the time?  If you say no to either or both questions, and you want your church to sound right for speech and music, the biggest obstacle is often the acoustics.  The second is money.  The third is aesthetics.

Fix the room!  How?  Follow what the Bible says, and you will not be disappointed.  After all, it is God’s plan, not man’s idea.  Do you think that the results will be less than perfect if you follow His plan completely? Isn’t the Bible the Living Bible?  Since when did the Bible stop teaching us new things about science?  Check out Solomon’s Temple, and the answers are there.  They always have been. It’s just taken a while to join the dots.

But it costs too much!  Oh, you mean the cost of a few floor monitors or a couple of wireless microphones considered too much?  That is often the cost of the Bible’s way of fixing the acoustics or about $3.50USD per seat for a 300 seat church. (Not including the price for the knowledge of knowing what to do.)  Replacing a mixer costs about $15.00-21.00 per seat.  Replacing pews for chairs cost about $75.00 per seat.  Buying 10 Shure SM58 mics with cables and mic stands – costs about $1,500.00.  Fixing the acoustics of a church is cheaper than you think.

If the look of any acoustical treatment is a concern, ask yourself this.  Are you there to worship God or the building?  Fixing the acoustics is like saying you are more interested in hearing what God has to say through your minister.  Putting up with acoustical problems, poor quality congregational singing, and accepting a sound system with limited performance is like saying the building is more important than the message and having fellowship with other believers.

It all comes down to priorities.  The primary purpose of any building that is a dedicated House of God is the preaching of the Gospel.  A place where the Gospel message can be spoken without distortion or interface.  That includes making the room behave as God would want us to have it.  The second priority is the breaking of bread and drinking of wine in remembrance of what Jesus did for all of us.  The worship space has to support this event as often as each church chooses to remember.  The next priority is congregational singing.  There isn’t any other experience that can replace the joy and excitement of a room where more than 75% of the audience is singing.  Songs that tell stories of Jesus, his atonement of our sins, and of people who follow Jesus are powerful in bringing people together.  It takes the same quality of acoustics to hear clear speech as well as great congregational singing.  These are the things that matter when you are a part of the Kingdom of God.

While I do have a business about church acoustics and sound, there is no possible way for one person or one company to fix all of the churches out there that need help.  By making this public, it means that no one can patent it and force churches to pay a license fee. It means that no one can control it and inflate the cost of fixing existing and new churches.  Churches should use the Bible’s methods with confidence, to apply in faith what God teaches, even without expert help.  When churches take such a leap of faith, in most cases, the results are outstanding.

This information is being shared because I care more about winning people for Christ through better sound than creating a business empire.  By revealing what the Bible teaches, by showing that science backs it up, that it is affordable for every church to have excellent acoustics, this is all part of the Great Commission.  If more people with a passion and skills like mine, were to apply what the Bible teaches about sound, we could make a difference.  Mat-7:15.  Beware of false prophets, which come to you in sheep’s clothing, but inwardly they are ravening wolves. (KJV)  If you have the chance, read the rest of what Jesus said in Mathews 7:15-20. Don’t trust me.  Trust the Bible.

Posted in Church Acoustics, Church Sound Systems | Tagged: , , , , , , , , , , , , , , , , , , , , , , , , , | Comments Off on What are your Church Priorities about sound when it comes to preaching the Gospel?

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. The effect of standing waves are not always apparent. Standing waves are usually excess mid and bass frequencies of energy that masks the highs. You can’t hear a standing wave but you can hear the effects of it. To identify if your church has standing waves, go between any parallels 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 the presence 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 you, the standing waves are the cause of it. The standing waves are masking the highs, creating the effect as if it is 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 you from hearing the returning clap. Standing waves have other detrimental effects too. It has the effect of isolating everyone from each other in the room. This result is also why the drums seems to sound so loud and yet, this is also why most drummers strike the drums harder than they have too. It is because they can’t tell how loud they are playing at any volume level. This outcome is also why many people sitting in the pews comment that they can’t hear themselves when singing, and it makes them feel alone in a room full of people. This is the number one cause of people being discouraged from singing.

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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New Church Sound System Equalization Schedule

Posted by jdbsound on February 17, 2016


Notice to all Clients of JdB Sound Acoustics.

If you are in a new church building or you have done major renovations in your church, you will have to re-equalize the sound system many times in the first few years.  Here is the schedule you should follow.

  1. First-year – After the 1st month, 3rd month, 6th month, 9th month and 12th month
  2. The second-year – After the 4th month, 8th month and 12th month.
  3. Third-year – same as year 2
  4. The fourth-year – after the 6th and 12 months.
  5. Fifth-year – same as year 4
  6. Sixth to the seventh year, every 1 each.
  7. After that, do touchup to do loudspeaker decay drifts. (as speakers get older, the surrounds and cone can become stiffer and less compliant and that changes the frequency response of the speaker.  Equalization often compensates for mechanical aging.)

It takes up to ten years for most buildings to fully cure or longer depending on how much concrete and wood is used in the walls and floors.  For that reason, the humidity of the church becomes lower and lower as the church ages which also changes the sound of the worship space.

Also, depending on the climate area you are in, you should be re-equalizing your church sound system for each season.  more so the further you are from the equator.  If you have a digital processor or mixer, you can have presets for the room changes.

If your church is somewhat airtight and the HVAC system is properly designed to maintain temperature, even during worship services, the tuning cycle after 6 years can be relaxed for Displacement HVAC systems.

Joseph De Buglio

 

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What is the difference between scattering sound and diffusion of sound? Are Diffusers Programmable?

Posted by jdbsound on April 26, 2015


The simple answer is as follows.  Half, quart or third round devices or objects individually just scatter sound.  A single barrel diffuser or tube radiator as I often call them just create a very uneven distribution of sound.  As single units, it gives about the same amount of performance as placing a flat object of the same size and placing at a 15 to 35 degree angle on a wall.

When using barrel diffusers in various sizes and/or in spacing varying from 0 to 30 inches and apply them to all of the walls in a confined space, you are creating a diffusive field.  You’re turning the church walls into a phase coherent sound field – like churches of yester year built between the 1400’s to 1700’s.  When barrel tubes are used as a system you can program them to only manage the acoustical problems you want to get rid of and at the same time create a more desirable sound field like real reverberation that is musical and supportive to congregational singing.

Barrel tubes spaced too far apart just scatter the sound and reduces some bass but does nothing much else.  Instead, you can program the diffusers to manage standing waves, bass buildup, notch a frequency or two and equalize a room.  You can also program them to lower stage noise, manage monitor spill into the audience and improve congregational singing.  They can also be programs to make the sound system perform better.

The software to program barrel diffusers is still in development.  In the meantime, a test room, and a data base of real world testing is the best way to predict the final outcomes.  Try and program a digital EQ to cut 350 hertz 40dB.  It can be done but it sounds awful.  When you program tube radiators to cut 40dB, it sounds sweet.

Joseph De Buglio

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I Hate Mute Switches!

Posted by jdbsound on April 19, 2015


At my church, we still have an analog Mixer.  It has 24 channels, 4 sub groups, Left/Right and Mono out.   We use the sub groups.  Vocal, Drums, Instruments and Leadership mics.  The mixer has mutes on every channel, on each of the mute groups and on the 3 master outputs.  Fortunately, we have a church were the acoustics are stable.  We can run all of the mics open without feedback for normal worship levels. Monitors are stable and so on.  It is also a good sound rig.  When I run the mixer, I turn every channel on and shut off any mute switches.  I control all of the levels with the sub groups.  I don’t want any surprises.

This Sunday it was my turn to run the mixer as we are on a weekly rotation.  Thursday night was rehearsals.  Missed the rehearsal.  Friday night the Youth used the sanctuary and someone used the mixer.  Things were changed but it only took about a minute to set everything back.

As usually, you arrive at the church early for a pre service warmup. Dialed up a great monitor mix.  Everything seem right and as typical, we rehearse and warm up with the FOH speakers off.  When the worship team stopped it was time to turn on some background music.  Turned on the CD player, saw activity on the channel, raiser the fader for the channel and the channel was assigned to the Mono Main Out.  Raise the mono out and nothing happened.  What!!!

Checked the power switch to the powered speakers.  Check to make sure the processor was on and passing a signal.  Nothing.  Called the head tech for the church, he checked everything out. He checked the mixer and he agreed with me and thought that the power switch was faulty.  He removed the power switch and bypassed it.  Still no sound!  Double checked and found that the power lights on the back of the powered speakers were indeed on.  The head tech and I stared at each other confused wondering why there was still no sound.  Then he looked at the mixer again and this time noticed that the Mute switch on the Master Mono Main out was engaged.  He hit the mute switch and the rest of the sound system came to life.

In the year of mixing at the church, the Main Left/Right and Mono outs have never been muted.  The mixer is a spilt mixer where 16 channel are on one side of the mixer, 8 channel on the other side of the mixer and the Groups and master outs are near the middle of the mixer.  For some reason we were blinded in not seeing the red mute lights in that area of the mixer as there are other red lights in the area for other things.

Later I learned that a recently hired youth leader came from a church were the sound system was so unstable that you had to mute everything all the time.  They muted anything that wasn’t needed and because they left the mixer on 24/7, they had the habit of muting the master outputs as well.  The head sound tech and I had a good laugh at the whole experience.  For me, I should have known better as this is about the 3rd time something like this has happened.  This is the first time with powered speakers, but before I had people thinking there was something wrong with the mixer.  So please, unless you have a wonky unstable system, please don’t use the master mute switches.  They are great for a studio but not for live sound.

Joseph De Buglio

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Question! What would you do to fix the Acoustics of this Church?

Posted by jdbsound on April 1, 2015


You have a church that seats 750 people.  It is a simple rectangle room with 30 ft walls, 40 ft to the peak, 80 ft wide and 140 ft long.  The reverb is 2.2 seconds at 300 hertz and 1.3 seconds at 2000 hertz.  An Energy Time Curve test show reflections over 30dB at one second on the ETC in the 300 hertz range.  The floors are carpeted and the pews are padded seats and backs.  All of the walls and ceiling are insulated drywall on 12 inch centers.  Basically there is about 30dB of excess energy at 300 hertz.  300 Hertz has a wave length of 3.75 ft. The church has already tried 4 different sound systems over 10 years and all of them were designed and installed by companies that are supposed to be the best in the business and they all started off saying that the room needs to be fixed – but church board members vetoed anything that would change the aesthetics of the room – but it was OK to hang 2 ugly line arrays which lasted only 6 months.

The church is now asking for another sound system but this time all of the professional audio companies turned down the project and said to the church don’t call us back until you fix the room.  Now the church board has relented and they are allowing acoustical panels to be mounted on the walls. What acoustical method or system would you use to fix the problem?  What will reduce energy 30dB in this space?

For all the walls in the church, between windows, doors and bulkheads, there is only 35% of the total wall space available to mount acoustical panels on. Major issues are – Stage noise, floor monitors as loud as main speaker system in the first 10 rows.  Only 20% of the congregation is ever singing. Speech intelligibility is below 85% in full range – if you roll off the sound system at 200 hertz speech intelligibility improves to 88%.  Gain before feedback is very poor after 3 or more microphones are turned on at the same time. Subs never really sound right.  Pastor hears echoes all the time off the side walls when preaching. Drummer can never hear himself or the other worship team members – even with the headset monitors. The are currently using electronic drums but they have tried drum shields and booths without much satisfaction.

The church used to have a 40 voice choir but they never sounded very good and now with over $150,000 invested in a praise and worship team with all the latest state of the art technology and higher trained sound engineers, they sound no better than what the choir did years ago – but they are better at entertaining people!

(note: this is a fictional church but this is based on actual events that have happened recently in three southern Ontario Churches.)

Joseph De Buglio

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