As you visit other churches for weddings or other reasons, you probably have noticed a number of different sound system designs.
Some churches have column loudspeakers on the front walls. Another church will have many loudspeakers on the side walls. There are churches that have loudspeakers in the hanging light fixtures.
Others have many loudspeakers mounted under the pews. It is apparent that there are many different approaches to providing a sound system.
This article explores the basic concepts of another design approach called the central cluster loudspeaker system.
First, what is a central cluster loudspeaker system? It is usually applied to a system where the loudspeaker or loudspeakers are placed close together.
Then, the loudspeaker cluster is most often positioned above the platform in a central location. Hence, the name is a central cluster loudspeaker system. There are often slight changes in design and position, but the basic principles are the same.
Figure 1. Click to enlarge.
Why would a sound system designer want to use a central cluster loudspeaker system? One reason is that a properly designed system can provide a room with very even coverage.
This means the sound level (volume) will be very even from the first row to the back row and from side to side. In other words, no dead spots! Because the loudspeaker(s) are mounted high overhead, the difference in distance the sound travels to reach the back row or the front row is minimal (Figure 1).
And with the proper loudspeaker selection and their positioning, even the differences in distance can be compensated for. However, the key to success is proper design. The designer must understand the coverage patterns of the loudspeakers and how to use them.
Another benefit of the central cluster is that it provides good localization. That means the amplified sound will appear to come from the talker. It is generally accepted that our ear/brains can locate positions side to side better than vertically.
Therefore, when the amplified sound comes from an overhead loudspeaker system, we can more easily accept that the sound is coming from the talker. This provides a more natural listening environment.
Figure 2. Click to enlarge.
The other major benefit of a well designed central cluster is its ability to provide sound with the least amount of interference between the loudspeakers. What this means is that a listener should only hear sound from one loudspeaker.
If he hears sound from two loudspeakers and the loudspeakers are at different distances from the listener, the combined sound may be difficult to understand (Figure 2).
In fact, if the two loudspeakers are far enough apart, the listener may even hear two distinct sounds. The echo can really destroy intelligibility.
You may be asking why every sound system is not a central cluster type system. It would appear that it has many advantages. However, you should also have noticed the repeated phrase about a properly designed system. That is a most crucial point.
A sound system must be designed for every unique worship space. What works in one church could sound terrible in another church. For instance, a central cluster will probably not work well in a church that has a very low ceiling and is also very long.
A wide or fan shaped room often requires a different design approach. Another situation may be a church that has an extremely long reverberation time. Headphones might be the only way to achieve clear, understandable sound in that church.
We have all been in a church where the sound system was great. And unfortunately, the opposite situation occurs all too often.
What’s the difference? Acoustics naturally play an important role. Even a church with the best acoustics can have a terrible sounding sound system. The sound system must be designed to fit both the specific individual room and the uses it will serve.
Ron Huisinga is an audio industry veteran and President of New Life Communications who has a strong personal commitment to educating people about sound operation by sharing his knowledge, experience, and skills through articles like the one featured above from the Internet Sound Institute.