It’s a fairly well-known and accepted observation among consultants, contractors and manufacturers that cater to the church sound market that almost all houses of worship (HOW) go through several sound system designs before they get one that provides acceptable performance. You’ve probably read words to this effect here in Church Production Magazine. This very unfortunate trend is far more prevalent in the HOW world than in the other markets that we serve. Based on my experiences, performance venues fare much, much better. These purpose-built facilities are typically willing to spend as much money on acoustics and sound system consultants and designers, plus the equipment required, as they do on anything other “ingredient” for their facilities. Why? Because their future depends on their being able to provide very good sound quality so that the patrons who buy tickets (and also the visiting performers and their technical crews) are happy with the show and are more than willing to come back.
So how can churches be any different? Are we not as concerned that the singing and spoken word are clear and intelligible? Don’t we want folks to be inspired and eager to come back?
Here’s another question: Why is it that many HOWs don’t hesitate to spend money on building, renovating and/or up keeping their physical property but they choke at the prospect of investing reasonable funds into making it possible to have good quality worship sound?
Most churches and their building committees make the simple mistake of assuming that the acoustic performance of the sanctuary is less important to their services than the other physical considerations they are faced with. Tied closely to this misconception is the notion that acoustic problems or inadequacies can be dealt with ‘somewhere down the line’ and also with an assumption that this makes good fiscal sense.
Two rules of thumb that are worth your considering and remembering are:
- Anything costs less to do it right the first time
- Acoustics problems are hardly ever inexpensive to fix
It is way beyond the scope of this article to provide detailed insight into what is needed to get the acoustics right for the varied sizes of worship spaces that we use, not to mention for the equally varied musical styles and multifunctional needs that a church may use.
But I can tell you from years of experience that randomly placed inexpensive and homemade acoustic treatments are almost always just as destructive as they might be beneficial. They commonly present safety hazards and hardly ever are considered to be visually attractive.
Simply put, the acoustic character of any space will fall into three basic categories: too dead, too live, or somewhere in-between. The appropriate acoustic character of a space used for contemporary worship (and performance, public speaking, assembly, etc.) falls somewhere in the middle. It needs to be somewhat live, but not too live. Just to give you some base numbers, in general acousticians prefer reverberation times as follows:
| Type of Presentation | Preferred Reverberation Times |
| Cinema | 1.0 second |
| Amplified Pop Music | 1.0 second |
| Speech | 0.9 – 1.2 seconds |
| Drama | 1.0 – 1.4 seconds |
| Opera | 1.2 - 1.4 seconds |
| Symphonic Music | 1.3 – 2.5 seconds |
Note: reverberation time (RT60, T60) is the amount of time it takes for the sound field to decay 60 dB.
These reverberation numbers should give you a glimpse at how diverse these events are in this one required acoustic characteristic. There are others, as well. In addition to reverberation, which consists of multiple and completely random reflections bouncing off many varied surfaces within a space, and which we do desire to an appropriate degree, there is another acoustic characteristic that is never desirable and will hinder the sound in one way or another. This is the presence of discrete echoes. Sound that is reflected back onto the audience or to the platform and which is heard as a separate sound, or echo, will reduce intelligibility of spoken word and clarity of music. Such reflections, if they arrive at the listener’s ears well after the direct sound does, will simply be heard as “slap-back” echoes.
Simply put, a box-shaped space with flat walls, floor and ceiling made from smooth/ hard surfaces is usually not the best shape for public events. In order for such a space to work, the room surfaces must be broken up into multiple planes or (ideally) multiple shapes consisting of bumps and cavities. This is true of all box shapes: concert halls, warehouses and retail spaces, small traditional chapels, cathedrals, cafeterias, auditoria, lecture halls, etc. Other room shapes, including the fan-shaped sanctuaries that are popular these days for larger churches, must also be further “de-boxed” in order to provide acceptable acoustics. A fanshaped room with a flat rear wall that is parallel to the platform will suffer from echo problems.
In any space that does not provide the proper surface orientations and construction, the most common correction technique employed by the novice is to apply absorption. Those who attempt this employ various and commonly available treatments such as fiberglass and foam, which when placed directly onto the room surfaces yields an uneven acoustic response. This treatment does “kill” higher frequency reflections but has little effect at middle and lower frequencies.
In most cases, the most constructive treatment is to employ diffusion, plus some absorption. Diffusion, in the form of carefully designed surfaces with bumps and cavities, breaks up the reflected sound into diffuse, or scattered, sound. This is necessary to maintain “liveness” while reducing the destructive discrete reflections, including echoes. Such devices are virtually impossible to construct on one’s own and require expert application in order to work effectively and without excessive cost. Applying such treatment to an existing space can cost much more than it does during initial construction.
At the other end of the spectrum are the spaces that are simply too acoustically dead for worship. Such spaces require a sound reinforcement system for any event that takes place. They usually are further hampered by a complete lack of acoustic envelopment, which (if present) assists the congregation and those on the platform to feel (and sing) like a congregation. Such a problem can, in some cases, be improved somewhat by strategically removing absorptive architectural elements. Another course of action is to design and install an electronic acoustic enhancement system, which is not inexpensive but costs much less than rebuilding or enlarging the space.
For a good number of worship facilities where there will be widely diverse styles of worship and other programming requirements, such as those with traditional and contemporary worship services, it may be necessary to provide adjustable acoustics. Such designs may employ retractable curtains and reflectors or they may feature electronic acoustic enhancement. In facilities with effectively designed adjustable acoustics, a wide range of music and other events can be produced with optimal acoustic atmosphere and sound quality.
One overlooked potential acoustic problem that exists far too often in houses of worship and performance venues alike, is the presence of background noise. The dynamic range of both music and spoken word is such that at times the sound level is very low. The silence that exists between words and sentences and also between musical passages is a crucial element to understanding what is being conveyed and our perception of both the spiritual, intellectual and musical aspects of what is being performed. Noise from air-handling systems, furnaces, air conditioners, lighting and also from nearby street traffic are the primary culprits of background noise and can be minimized or prevented from occurring within the sanctuary without significant extra costs, if dealt with prior to installation and during construction.
The most prudent method of ensuring that your new or renovated space will provide acoustics that are constructive and add to the worship experience is to employ a consulting firm that specializes in acoustics and sound system design for your particular needs. If brought in from the beginning and allowed to participate in development of your programming needs, such a firm can recommend the proper shaping and architectural materials, room fixtures and loudspeaker system for your church. They should also be capable of designing noisereducing elements into the various systems that will be employed. Utilizing such expert design from the beginning is always much less expensive than having to renovate or completely redesign the space once it has been built.
Tom Young is a Senior Consultant in electro-acoustics at Jaffe Holden Acoustics based in Norwalk, CT. JHA specializes in both architectural acoustics and electroacoustics for performance and worship spaces. For more information, visit www.jhacoustics.com.
