The great thing about mixing in the same house of worship week after week is that you become very familiar with the sound of your room. The not-very-good thing about mixing in the same house of worship week after week is that you soon accept the sound of your room as being correct when it may not be. Understanding the physical attributes of sound and how it reacts in your house will allow you to improve the sound in that house.
Whether you change some of the interior materials in your worship house or change some of your mixing techniques or a combination of both, the more you know how sound works the more proficient you will become.
In the Beginning…
Let’s start with some basics. In the average house of worship (remember, I am generalizing) the usable frequencies are from about 80Hz to 14,000Hz (14kHz). I am assuming you understand the more Hertz (Hz or cycles per second), the higher the pitch. These pitches travel in waves (sound waves) and they have a specific length (wave length). The length of the waves varies greatly. For example, at 100Hz, a sound wave has a length of 11.25 feet, while a 1000Hz wave has a length of 1.125 feet, or 13.5 inches. Get up to 10kHz (10,000 Hertz), and the length of the wave is only 1.35 inches. These waves also travel at a specific rate of speed. That speed is 1,130 feet per second (assuming it is 68 degrees F. and you are at sea level). That is pretty darn fast, which means sound happens almost immediately. Understanding these physical attributes of sound can open your eyes to what the music, singing and spoken word in your house is actually doing.
On the Bounce
Now what is the interior of you house of worship built out of? Most building interiors use one or more of the following materials: wood, brick, plaster, drywall or sheetrock, glass, concrete, marble, stone, linoleum and carpet. Not to mention window coverings such as blinds and curtains. Sound waves react and interact differently with all these surfaces. Let’s say you have a pair of speakers hanging above the stage of your worship house and 100 feet in front of those speakers is the back wall of the room. The wall happens to be constructed of concrete block with a plaster coating (in other words, a very hard surface). When the sound waves from the speakers hit the wall, a few things happen.
Some of the sound waves are reflected, the wall absorbs some of the waves and the wall lets some of the waves pass through it. If your house of worship fits the aforementioned scenario, you know you have a problem. We have all been in a high school gym. If you clap your hands or yell in the gym you will hear high and mid-frequency sound waves bouncing all over the place like a ping-pong ball on four cups of espresso.
The reflected sound is called reverberation, or reverb. Let’s take a closer look at how reverb works. You first hear the sound from your worship house speakers. An instant later, some of that original sound bounces or reverberates off the back wall of your church and into your ears again. In another instant, a bit more of the original sound ricochets off the floor and ceiling and once again into your ears. As more sound leaves your worship house speakers, more sound bounces into your ears. As this cycle continues your ears become overwhelmed with a wash of frequencies. This is an example of bad reverb. However, in many instances, small doses of reverb are very pleasing to the ear. The world around us is filled with reflected sounds and our ears recognize limited reverb as normal. But in the cases of too many reflected sounds, our ears have difficulty identifying frequencies.
Listen, Listen, Listen
This is where you need to know your space. Listen to your room. A room that provides moderate natural reverb can enhance the sound you hear in it. Music and voices sound fuller, and for most listeners, that is better. But there is a fine line here. Use your ears and you will have a better understanding of your worship space and how to work within it. Of course, using your ears may not be quite enough, you may want to use your feet as well. Walk around your house of worship during a service and listen to how the choir, worship band (if you have one) and preacher sound from different locations. If you have a balcony, get up there and listen. While you’re at it, listen from under the balcony. Listen everywhere in your worship room you can. Ask yourself questions like, “Can I hear every word the preacher is preaching?” and “Do I understand the words the choir is singing?” or “Can I distinguish the piano from the guitar in the worship band?” Whether you are mixing a service or not, get your ears tuned up to the entire space.
You now have an idea of what bad (too much) reverb is. But what if your house of worship has no reverb? This would be referred to a room that is “dead,” whereas too much reverb is called “live” or “too live.” If your room is “dead,” you will have to add some reverb in artificially. That would mean the use of some sort of outboard device. A “dead” room isn’t necessarily worse than a “too live” room, it’s just a different situation, and it’s actually easier to remedy.
Whether your house is “live” or “dead,” we will not be able to fix your specific situation in this installment of Sound Sanctuary. So, for the very first time in my many years of writing, I am presenting this subject in an episodic format. That means that next month we will discover together all the things that can be done to control and improve the sound of your house of worship.
