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anruari
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Distributed Line array speakers.
The most common form of loudspeaker used in churches is a “Line Array” this is a column of speakers, stacked 3, 4 or 5 high. this may be straight or curved.
It should allways be angled so the top speaker is pointed at the heads of the people who would be standing in the pew where the next pair of speakers is located (this is often not done right)
The array design results in the sound being very accurately pointed at the congregation, and as little as possible being bounced off the walls, and especially a major reduction in noise being pointed up to the high ceiling.
The effect of this design, when installed correctly is that
- the source of the amplified sound is far closer to the listener than the original sound. This means they are more likely to hear the original sound before it gets lost in the reverberation mush. Also a reasonably full congregation area will absorb the sound that is pointed at it, and that sound then won’t bounce around the church.
- The amplified sound is actually louder.
For a church that’s 50 from the altar to the back pew, the direct sound of the priests voice will be 34dB lower than it was 1 yard from his mouth. The reverberant sound may be only around 10 - 15 dB lower. therefore you only hear the reverberant mush and not the actual speech or chant. Loudspeakers on each column mean that you’re only a few yards away from the nearest loudspaker, and hear it’s sound before the reverberant mush takes over. (and that’s before you turn the volume up) - In very long churches, it is possible to add a deliberate delay into the signal chain so that loudspeakers speakers more than 20 - 30 yards from the pulpit have their sound singnal delayed slightly so that the sound from the priest and the sound from the loudspeaker arrive closer together in time.
This can be applied to the whole system if budgets permit.
The advantage of this, in a conservative system is taht you reccognise the source of a sound based on the first sound waves to reach your ears. If the sound from the loudspeakers is set to be just a few milliseconds behind the sound coming naturally from the priests mouth, and the system is designed sensitively it is possible to be completely unaware of the sound system until it fails.
Unfortuantely most parishes, and even many cathedrals cannot afford to pay for such sophisticated systems. but they are used widely in Theaters where Classical music, and Opera are performed,
So: If the sound system in your local parish church is not up to much, consider taking up a collection and raising about $10,000 to pay a professional acoustic engineer to assess the building and design you a proper system, then have a seperate supplier install and fit the specified system. Dont trust a product supplier to design the best system for you… they have a vested interest in selling you the products they have in stock or can most easily supply. this is what caused the bad installation in the first system.
Some systems can be greatly improved by just re-directing the existing Line array speakers. - they should be angled downwards to that a straight line from the middle of the top driver is pointed at head height at the middle of the pew where the next pair of loudspeakers is located.
Only very big chapels need delay systems.
Make sure no speakers are able to direct noise upwards, or have their sounds bounce off walls which are more than a few inches away.
Make sure the Priests and all other readers etc are taught to speak slowly and clearly. You should be able to understand eachother speaking from the altar rail to the back row of seats (or a few in from the back if theres a wall right behind the back row) in the empty chapel. That’s a good indicator you’re speaking slowly enough.
Then the amplification system will help to overcome the sounds of the other members of the congregation. especially the babies, toddlers, rustlers and coughers.