* * * You may want to copy or print this. It is long.. * * *
The following article was first written by Joseph De Buglio in 1988 and published in 1991 for Your Church Magazine. It has been Updated Jan. 1996.

Part 1
TROUBLE SHOOTING CHURCH ACOUSTICS,
THE PRO'S AND CON'S.

From the JdB Church Sound Series

or

Why Band Aids Don't Work well in Open Heart Surgery.


Part 2
After the fact methods of fixing room acoustics


© By Joseph De Buglio 1996
In the world of Church Acoustics, almost every house of worship has to be able to perform for many complex events during a worship service.
First and primary, a house of worship must be a place where you can hear the spoken word without fatigue or stress. (Fatigue and stress is when you are spending most of your time trying to hear rather than understanding what was said.) Therefore, you could say that a house of worship must perform like a lecture hall.
The second function of a house of worship is congregational singing. This is when the churches should sound like cathedrals. It is when 10 people should sound like 30 and 30 people should sound like 100 people. Therefore you could also say that for congregational singing a house of worship must perform like being on stage of a great concert hall. Please note that this is for people in the pews , not on a stage or altar areas.
The third function of a house of worship in choral singing. This is when volunteers from the congregation sing selected songs in preparation for the coming sermon. Once again the choir loft needs to sound like being on stage of a great symphony hall.
The fourth function of a house of worship has many element. It is for special music and drama events. This music can be a soloist, a Gospel group, an instrumental group, a church orchestra playing to a small group of singers or a piano or organ solo. There is also a growing number of churches that amplify the voices of a worship team to help with leading or supporting congregational singing. For some churches, special music changes every week. This is when a house of worship has to perform like a live recording studio.
The fifth function of a house of worship is lecture, funeral and weddings. These are special events that require unique attention. For some churches, in a given week there can be all of these events. For a funeral, most people expect the house of worship to be dignified and ceremonial. For a wedding, the house of worship should be happy and cheerful.
All of this has been said to point out one thing. A house of worship in any denomination is more complex than any secular institution of it's size. Therefore, the acoustical needs of a church are unique to churches and only churches or "Houses Of Worship".
Did you know that there are over 400,000 churches in North America and there are no documented standards of any kind that determines how a house of worship should perform? To the best of my sources, this is true. Therefore, how can any Architect (who typically had only 5 to 8 hours of acoustical training) begin to phathom what kind of acoustics a church needs or wants? Because of this dilemma, experts in acoustics have becomes experts in offering high priced Band-Aids that requires a huge background in mathematics to solve problems that could have been avoided. For most churches, these expensive problems could have been avoided for a fraction of the cost of consulting and building the solution into the building. (Typically, a church that cost $50 to 70 per seat to repair can usually be done for about $10 per seat or less while being built.)
Why is this such a big deal? Many churches have acoustical problems and the problems are serious. Of over 500 churches checked at random, 6 of them had good acoustics and 2 of them had great acoustics and excellent sight lines which matched the style of worship that church practices. Approximately 1% of our churches in all denominations have good acoustics. Is this normal? Don't people want to hear, enjoy all parts of Sunday worship and participate? Should we use terms like chronic, terminal or epidemic to describe the listening conditions in our church communities?
Although many people are familiar with the line, "faith comes from hearing" (Romans 10:17), how many of you are familiar with the context of that part of scriptures? In the NIV, Romans 10:14-18 there are 10 references to hearing or communicating the spoken work. To drive this point a little further, ask yourself these two questions. When was the last time you meet someone who was converted to Christianity because they saw a miracle? When was the last time you met someone who had a miracle in their lives and came to Christ because of a message they heard? Just because people hear a noise when the minister speaks, people take it for granted that they understand it.
It is amazing that in spit of all of our wonderful technology, hearing in the pews must rely on laws and principals discovered over 3000 years ago by the Greek's. These laws were used by Jesus at the sermon on the mount and along the sea of Galilee. Today, the majority of Architects (including the "Christian architect" who were trained in the secular Architectural system,) ignore all that is known. And, the church community is just sitting back and watching our church community split and fragment. What is the most common thread for church denominations to divide and split so rapidly in the past 30 years? Church sound has played a bigger part in church divisions than our church leader would care to admit.
A church's appearance is import, but I have a hard time when Architects put visuals above hearing. After all, just as some older churches have beautiful art work and paintings that are priceless, and other churches have some real fancy architecture, I don't often see people going to a museum to look at the same art work for an hour or two every week. (It would be simple to have a church that is both Architecturally ornate and have excellent acoustics at the same time.)
Chances are, in your church, or you know of a church, people are spending most of their time trying to hear rather than understanding what was said and the average person in the pew is not even aware that there is a problem.
The core of solving the problem is rather simple. If each denomination were to write a performance specification for the acoustics and the audio system for their churches and make it conditional in the contract with your Architect, builder, or audio contractor, more churches would have better acoustics.
In the mean time, there are over 350,000 churches in the US and over 90% of them do not have adequate acoustics for reasonable hearing, congregational singing and music. What can churches do to solve their problem?
Before a church tries a solution, they must have a doctor, (acoustical consultant), come in and make the right diagnosis. But! How do you know if the consultant is doing his job? How is the layman suppose to understand the report? Here are a few key points to look for in an acoustical report.
  1. Just as a speaker has a frequency response or signature, so does the acoustics of a room. Therefore, in the report, there should be a frequency response of the room from 20 hertz to 15,000 hertz which also shows the length of reverberation in 1/3rd octaves.

  2. There should be a prediction of the frequency response of the room after the repairs are done.

  3. The prediction should be conditional within the contract and the consultant (or the company that does design/build) should be held responsible, not the contractor.

  4. Have the consultant show you how the measurements were taken so that when the consultant returns after the repairs are done, you will be able to see the results for your self.

  5. Do not accept a measurement at 1K or an average reverb time to determine before and after results.

  6. Depending on the shape of the room, (a.) side walls should be fixed to support speech. (b.) rear wall must be diffusive, not absorptive (c.) front walls should be hard and shaped to amplify music and speech.

  7. Echo's should never be repaired with a flat surface system such as flat fiber board panels, tiles or carpet. These solutions create other problems. Echo's require diffusion. Therefore cylinder, large angled panels and large protruding artwork give the best results. Brick work with protrusion greater that 10 inches works very well too. Other classical and effect echo reducers are pillars, statues, wall carvings, water jugs and hollow stones are very effective. But, in today's society, churches would be thought of as being too extravagant or worldly for such inexpensive solution.

  8. Churches with side and back walls less than 25 feet high should not have a balcony with seating under it. If you have a balcony, do not have any seats where you can not see the ceiling over the pulpit.

  9. Never paint a church without knowing what you are doing. A $4,000 paint job can cost $100,000 to fix.

  10. In the consulting report, you should be able to determine the RT60 at 100, 200, 400, 1000 and 2000 hertz. If you have an acoustical problem in the lower frequencies such as 100 or 200 hertz, the acoustical treatment must be designed to absorb those frequencies. Most churches already have problems between 130 hertz to 400 hertz. A church that has a long RT60 at 200 hertz will require and acoustical treatment design to absorb wave lengths of 5.65 feet. Some consultant will say that you can use items that absorb 1/4 the wave length. However, you will need 4 time more product. It may be better to have some corner bass traps than large panels that cover a whole wall.

If your consultant does not address or do all of these things, then hire another consultant. Unfortunately there is no Government medical plan that pays for these consultations so you better do an on site review of the consultant you are considering to hire.
The Following is from the book "Why is Church Sound So Confusing?" It is a simple performance spec. every church can use to follow.
  1. RT60 for traditional and liturgical services should be __(It's in the Book!!)__ seconds from 170 hertz to 3000 hertz .+/-__ tenths of 1 second. You can increase the reverberation by __ tenths of a second if the church only does classical music programs. If the church plans to include contemporary music, shorten the time by __ tenth of a second more.

  2. RT60 of ____ seconds from 170 hertz to 3000 hertz .__ tenths of 1 second for Evangelical and Protestant churches with light to medium music programs.

  3. RT60 of ___ seconds from 170 hertz to 3000 hertz .___ tenths of 1 second for Charismatic and Pentecostal churches with a heavy modern music program.

  4. There shall be no _________ walls.

  5. Any wall further than ___ feet from a speaking position and larger than _____ square feet should have an object mounted on it for diffusion purposes. Or, the wall can be constructed into smaller walls which will reflect sound into other areas.

This spec. is measurable and not unreasonable. From blueprints, it can be determined if the room will perform properly. This spec. of performance should be made conditional in your contract with the architect or builder right from day one. This spec. will help the Architect to plan a room shape that will provide these condition. Doing it after the fact is already too late. Once an Architect submits the first set of drawings, the church will have spent thousand of dollar. To redraw a building can cost thousand more. An expense most churches are not ready to spent twice. Remember, this church is being custom made for you and you now have a detailed method of expressing your needs. If you have read this and you accept a new church that fails to meet your needs, not only do you lose, but all of the members of your church lose as well. The above section from the book is applicable to existing churches as well.
Part 2 After the fact methods of fixing room acoustics

Some statements and Specs have been blanked out under the understanding that it is part of the "intellectual Knowledge" guidelines and were not part of the original article. Such knowledge has value and can be purchased through investing in the book "
"Why Are Church Sound Systems and Church Acoustics So Confusing?"Info on a book on Church Sound System & Church Acoustics
Back to THE LEARNING CENTER
Church Sound Network
63 Lockerbie Avenue, Toronto, Ontario Canada M9N 3A3
For questions or comments, our e-mail address is - csn@jdbsound.com
Copyright (c) 1996 JdB Sound, Acoustic Lab.




*