Not every house of worship has the luxury of selecting from multiple locations for its front of house speakers. Some of you have but one place to position or mount your speakers. However, it goes without saying that the placement of your speakers — their location and where they are aimed — is of monumental importance in how your system performs in your sanctuary.
First, a Few Basics
But before we get to the particular make and model of your speakers and where you should place them in your church, we need to understand what is coming out of those speakers. Like all sounds, the audio that emanates from your speakers is represented in frequencies, and those frequencies travel in waves. Very importantly, the waves have a specific length. First, sound travels at approximately 1,125 feet per second at sea level in dry air that is about 70°F. That is about 765 miles per hour. I noted “sea level” and “70°F.” because sound slows at higher elevations (where the air is less dense) and also slows as the temperature drops (even though colder air is more dense.)
You can puzzle that one out, but either way, sound obviously moves fairly rapidly. Fast enough so that everyone at a Sunday service will hear the worship band and the message at the same time. Now that 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 (your speakers) 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 a 440 Hz “A” note. This frequency common to the “A” string on a guitar is 440 cycles per second (or Hertz). That frequency has its own wavelength. You can figure out the length of the wave by dividing 1,125 (the speed of sound) by 440 and you get a little more than 2.5 feet (30 inches).
Dropping down to 100 Hertz, and by using the same formula, you get a wavelength of 11.25 feet. That’s pretty long, but a 50-Hertz wave is 22.5 feet in length, and a 1,000 Hertz (1 kHz) wave is about 13 inches. “So what?” you may be saying to yourself. Let me explain. Even though all the frequencies are traveling at the same speed, the various wavelengths interact with the interior of your sanctuary. That means all the materials and surfaces the sound waves encounter — not to mention all the people in your congregation. It doesn’t take long to figure out that, with all the frequencies and wavelengths, the placement and position of your front of house speakers is very important.
Get Involved!
So what are you going to do about it? First get yourself 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 available, and they are free or very inexpensive.
Now with the tools (apps) in hand, turn on your worship sound system and put on a CD (or tracks from an iPod or CD or whatever sound source you have). I like to listen to real music when I am doing my adjustment rather than white or pink noise. Anyway, put on something you are familiar with and check out different locations in your sanctuary.
You will discover certain locations that are louder and other locations that are quieter. In some areas, the frequencies will be smooth and natural-sounding; while in other areas you’ll probably encounter 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.
A Little Experimentation
Now that you really know your worship space, can you make it better by changing the placement or angle of your speakers? If your speakers can be moved and can be aimed fairly easily, you can begin experimenting with your system. You will need a laser level for this next step. You can buy one pretty fairly inexpensively these days. Now, set the laser on the top center of one of your speaker boxes. (I am assuming you have one speaker enclosure per side. If you have more, just multiply this technique by the number of boxes.) Turn on the laser and see where the beam hits. Mark with a piece of tape on the seat, floor or wall — wherever the beam lands. Repeat this with the speaker box on the opposite side and note again with a piece of tape where the beam hits. This location of your front of house speakers will be the default position.
Next, 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 work 15 minutes before service next Sunday. 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 get in the way of your search for perfection, and a major factor on that is the material that populates the interior of your sanctuary. What are the walls constructed of and covered with? What’s on the floor? Do you have windows? If so, are there curtains? All these things affect those sound waves. However, I will save that discussion for another time.
