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Sound Advice

Practical comments on bringing new life to acoustically dead sanctuaries

The building committee needed a break. They had been discussing the acoustical problems in their sanctuary for over an hour. They had read the complaints, studied the estimates from a contractor, and argued back and forth about the importance of a good sound system.

"Maybe we can find some direction in Scripture," the chairman suggested. Together the committee members looked up as many scriptural statements about hearing as they could find. Gleaned were the following: "You shall hear but never understand." "Blessed are those who hear." "I should like to hear this man myself." "No ear has heard." "Why do you not understand what I say?"

While biblical scholars may shudder at the way in which the committee took texts out of context and "manipulated" Scripture, many congregations will (so to speak) resonate with the committee. Sound problems and acoustical woes, after all, are common in existing church buildings.

In an attempt to provide answers to some of the questions many churches are asking about sound problems, RW asked acoustical expert Harold P. Geerdes a number of questions about church acoustics and sound.

RW: Why are the sound problems in a church sanctuary more complex than sound problems in other buildings?

Geerdes: In a typical auditorium/ concert hall the audience listens but does not participate. It is important that they be able to hear the performers on stage but not that they be able to hear one another.

In a church sanctuary, however, where the congregation joins in by singing and speaking, acoustics are as important in the pews as they are in the pulpit.

RW: From the acoustical standpoint, what would the ideal church look like? How important is the size of the sanctuary?

Geerdes: The ideal church might look very much like our traditional church buildings. The rectangular shape and high ceiling that we all are so familiar with are ideal for good acoustics.

When it comes to sanctuaries, big is usually not better. Ideally, a congregation should build a church in which everyone can hear the spoken word with a minimum of amplification and in which congregational singing and the music of choir and organ can be joyous and inspiring. Witness the Crystal Cathedral. The sanctuary is so huge that it requires several sound systems and a large television screen to project the preacher's voice and image to distant seats in the huge auditorium. The Cathedral is a unique piece of architecture, but far from ideal acoustically for worshipers.

RW: Are some interior designs (including the placement of furnishings) better than others? What should one avoid?

Geerdes: Avoid big balcony overhangs, cruciform layouts with seating in side "annexes," and acoustical ceiling tiles. Also make every effort to exclude heavy pew cushions and carpet. If you must use carpet in any part of the sanctuary, be sure to select a low-pile carpet and to glue it directly to the floor slab. The pulpit area should be hard-surfaced with wood or tile.

RW: How about building materials and textures?

RW: Irregular, uneven surfaces are desirable because they help disperse sound. One church in my area used split-faced block for the exterior and flat block for the interior. They could have improved acoustics by reversing the two.

In any case, mass is important. Thin gypsum-board walls with wide furring strips behind them become low-frequency absorbers that cause the bottom to fall out of the church's music.

RW: What's the best placement of the "sound originators" (for example, the preacher, the choir) in relation to each other and in relation to the congregation?

Geerdes: Ideally, the spoken word and the music should originate from sources no further than twenty to thirty feet apart. Keeping the choir close to the congregation (or actually within the congregational seating area) helps them lead and strengthen the congregational singing.

RW: Can some churches get along without any sound amplification system? How large can such a church be?

Geerdes: Yes, especially well-designed churches that seat not more than four to five hundred people. But even though many churches could get along without a sound system, few of them do. Today everyone expects booming sound. Even smaller churches are amplifying the spoken word.

RW: What principles do we need to keep in mind in designing a sound system?

Geerdes: Sound reinforcement should be more than amplification. It should be natural sound-ing, operating at a low level so the listener is not aware of it, and it should have point-source identification. By that I mean it should be obvious to the congregation that the sound comes from the preacher's mouth, not from one side or from multiple loudspeakers above. Obviously, many of our church sound systems are too loud, and the source is lost in the amplification.

RW:  What does that mean for the purchase of a specific system?

Geerdes: Well, before making such a purchase, the congregation should think carefully about the functions and purpose of the system. Just "louder" is no longer enough. The system should be no less state-of-the-art than the best systems in the homes of parishioners. Why have deluxe stereo systems at home and tinny, artificial systems at church?

RW: What about systems for the hard of hearing? Should a church invest in such a system?

Geerdes: Today we are blessed with new technology. No longer are those with hearing impairments sentenced to sit in the "deaf pew" with its wired ear sets. Today the congregation can purchase reliable but inexpensive wireless systems that permit the users to sit anywhere in the sanctuary and to control their own volume.

RW: Many churches are limited to their existing structure and can think only of internal changes. Sometimes they face serious acoustical problems—such as the pastor's voice that seems to come from the rafters. Can a congregation remedy such problems?

Geerdes: In many cases natural acoustical problems can be corrected. For example, a full acoustical-tile ceiling can be sealed or covered with gypsum board and plaster. A distracting echo from a rear wall can be lessened by placing absorbent materials on that wall, and so on.

If the preacher's voice seems to come from the rafters, the problem is probably in the sound system. A sounding board over the pulpit may be helpful in directing sound energy directly out to the worship space, thus reducing the need for amplification.

RW:  Sometimes the amplification system seems to produce an echo. How can this problem be solved?

Geerdes: Sometimes such a "ringing" or echo is caused by structural problems in the building itself. At other times the fault lies in the sound system. The problem is often difficult to isolate.

Often the problem is created by using the wrong kind of microphones or by failing to adjust the sound system output to the acoustical peculiarities of the room.

RW: What if the congregation's singing seems "dead"?

Geerdes: Dead, lifeless singing can often be traced to too low a ceiling and/or too many soft materials that absorb rather than reflect and reinforce the singers' voices.

The congregation can improve the environment by removing pew cushions and tearing out carpet from under pews. Ideally, the pulpit platform area should be uncarpeted too.

Sound is energy. If it is soaked up by soft materials near the speakers or listeners, it will not stimulate their hearing as intended. A high ceiling and hard materials are essential for inspiring hymn singing.