Not every House Of Worship has the luxury of multiple locations for their front of house speakers. You may have but one place to position or mount your speakers. That said, the location of the speakers and where they are aimed is of monumental importance in getting the best coverage and sound in your sanctuary.
First, we need to understand what specifically is coming out of the speakers: sound—and all sound is represented in frequencies and those frequencies travel in waves. Very importantly, the waves have a specific length. First; sound travels at about 1125 feet per second at sea level in 70 degree dry air. That is about 765 miles per hour. I noted “sea level” and “70 degrees” because sound slows at higher elevations and as the temperature drops. So, sound obviously travels very fast. Fast enough so everyone at a Sunday service will hear the worship band and the message at the same time.
Now, we know the approximate speed of sound, let’s look at sound waves. A sound wave is the pattern of disturbance caused by the movement of energy traveling through a medium (such as air). The wave moves away from the sound source (the loudspeakers) like the waves created by a rock thrown in a still pond. As these waves move they have a specific length related to their frequency. We all should be familiar with an “A” 440. This frequency common to the “A” string on a guitar is 440 cycles per second or hertz. That frequency has its own wave length. You can figure out the length of the wave by dividing 1125 (the speed of sound) by 440 and you get approximately 2.5 feet or a little over 30 inches.
Let’s drop down to 100 hertz and, by using the same formula, you get a wave length of 11.25 feet. That’s pretty long but 50 hertz is 22.5 ft. and 1000 hertz or 1 kHz is about 13 inches. “So what?” you may be saying to yourself. So, I will tell you what. Even though all the frequencies are traveling at the same speed, the various wave lengths interact with the interior of your sanctuary differently. That means all the materials and surfaces the sound waves encounter as well as all the people in your congregation.
It doesn’t take long to figure out that with all the frequencies and waves lengths, the placement and position of your front of house speakers if very important. So what are you going to do about it?
First, get a dB meter (or app) and a spectrum analyzer (or app). As a matter of fact, you should just get an app for your phone. There are many good ones out there and they are free or very inexpensive.
Now with these tools in hand, turn on your worship sound system and put on a CD or tracks from an IPod or other sound source. I like to listen to real music when I am doing my adjustments rather than white or pink noise. Play something you are familiar with and check out several different locations in your sanctuary. You will find some areas are louder and others are quieter. In some, the frequencies will be smooth and natural sounding while in other areas there will be harsher tones and possibly distorted frequencies.
Take your time and “map” out your room. Find the sweet spots—the areas, rows or specific seats where everything sounds the best. Now that you really know your worship space, the question becomes: can you make it better by changing the placement or angle of your speakers?
If your speakers can be moved are aimed fairly easily, then begin experimenting with your system. You will need a laser level, which are fairly cheap (there are no laser level apps, as far as I know).
Assuming you have one speaker enclosure per side (if you have more, just multiply this technique by the number of boxes), set the laser on the top center of one of your speaker boxes. Turn on the laser and see where the beam hits. Mark the spot with a piece of tape. Repeat this with the speaker box on the opposite side and note again with a piece of tape where the beam hits. This will be the default position.
Now try pointing the speakers in a slightly different location or direction. Adjust both sides equally and mark with a piece of tape (preferably a different color from the first piece of tape). With the speakers in their new position check out the sanctuary again using your audio apps and your ears. Are there now more sweet spots? Did you eliminate frequency or volume spikes? Did you improve the sound in your room or did you make it worse?
This process takes time but you are ultimately seeking the best possible sound you can find. So don’t plan on doing this in 15 minutes before Sunday service. Commit yourself to the process and keep good notes and records.
Ultimately you will find the best location, best position and best angle for your speakers. However long it takes you it will be worth it. After all, don’t you want the best sound possible in your church? Of course you do. We all want the best we can achieve.
There are a few things that may interfere with your search for perfection and that is the materials that populate the interior of your sanctuary. What are the walls made of and cover with? What’s on the floor? Do you have windows? If so are there curtains? All these things affect those sound waves. I will save that discussion for another time. —Jamie