A LONG ANSWER TO A SHORT QUESTION…
For as long as we’ve been in our sanctuary, there have been some folks who have had a problem hearing. Clearly certain voices are more problematic than others—but the problems also vary from hearer to hearer and can even depend on where you may be sitting in the sanctuary. We have experimented with a number of different adjustments to the sound system, including upgrading some components, but with only modest results. What we want you to know up front is that we take your concerns seriously and earnestly are seeking solutions. What we also want you to know is that this is a far more complicated issue than it sounds (pun intended).
EXPERT ADVICE HAS BEEN SOUGHT
As part of our choir loft renovation, we contacted our Audio-Visual contractor to come, plan, and price the relocation of some of our audio connection boxes that will be affected by the changes. In the process, we shared your concerns and the solutions we’ve attempted. He offered to have his acoustic engineer come when he came to lay out the audio connections. With his measuring equipment, he would measure the acoustic resonance of the sanctuary, and make recommendations. He also identified where we would have particular problems—which were right in line with what we’ve heard from many of you.
IT’S NOT YOUR IMAGINATION
The first thing the acoustician recognized is that we have a very strong resonance in the 250 Hz range….have I lost you? Let me try again…
The problem is that we have an echo—a pronounced echo of just over 4 seconds in the sanctuary.
Construction materials vary, but the dominant surface materials in our sanctuary are wood (beams and ceiling) and sheetrock. These materials in our sanctuary “resonate” (vibrate) in the middle of a typical hearing range. For reference sake, it’s just a shade below “middle-C” on a piano. Resonance means that the surface materials will reflect certain sounds more powerfully than other. In our case, a strong tone in the right frequency will continue to be heard in the room for just over four seconds.
WHY ARE MARY JANE AND STEFANIE EASIER TO HEAR THAN SCOTT?
It all has to do with pitch. My vocal range for speaking (unfortunately) falls right in the range of the resonance of the room. Mary Jane and Stefanie (and most women) speak in a higher octave and are not impacted so severely—but even they are not completely immune.
CAN’T WE JUST TURN UP THE VOLUME?
In an acoustically perfect space, turning up the volume would be the simplest solution. However, we have long known that in our sanctuary, turning up the volume can make the spoken word easier to HEAR, but harder to UNDERSTAND. In the world of Audio engineering, this is a dilemma between volume and intelligibility. Ideally you need to have both in good measure.
Intelligibility is impacted severely by other sounds going on in the room (ambient noise). It’s why you have a hard time hearing what is said on the television when a conversation is going on behind you. The echo in the room is like the conversation behind you.
Higher volume means more of what you want to hear, but also more of the echo that interferes with what you want to hear. At a certain point, the echo can completely overwhelm the clarity of the original source, resulting in muddled sound.
THE IMPACT OF AND ON THE CHOIR
Look up next time you are in the sanctuary. You will notice that the main speakers for the congregation are out in front of the choir. So the choir cannot hear the person speaking through the main speakers (except as an echo off of the back wall, perhaps). So the choir has it’s own set of speakers mounted on the beams to either side and pointed at them.
Again, in a an acoustically perfect world, these speakers would work exactly as intended and allow the choir to hear the preacher, the piano or other instruments, etc. And, if they couldn’t hear well enough, we could just turn up the volume.
But in our space, this presents a problem. Speakers pointed at the choir also bounce off of the wall behind them and project out into the sanctuary. More echo. And because the source of this echo is different from the other source (the main speakers hanging from the ceiling) the two echoes are “out of phase” which further muddies the sound.
We can’t turn off the choir monitors (that wouldn’t be fair to the choir), but we can’t turn them up too much because it seriously interferes with the sound in the rest of the sanctuary. Balance is the key, but the fundamental resonance of the room cannot be overcome just by getting the balance right.
After the funerals last week, someone came up and asked why they could understand me during funerals but not during church. Part of the answer is that the choir monitors were turned off during the funerals. It really does make that much difference.
WHAT IS TO BE DONE?
Acoustic treatments of various kinds are available and will be considered along with other options as they become known and available. Essentially an acoustic treatment consists of panels or a baffles that absorb sound rather than reflect it. Different materials absorb different frequencies, so identifying the proper panel densities and constructions are important (and best left to experts). In the same way placement of those panels is crucial. The Acoustician has suggested that we need approximately 1200 square feet of acoustic panels to reduce our echo by about half (you actually don’t want it to go to zero or the room sounds “dead”). That’s sounds like a lot, but there is an awful lot of exposed wall space in our sanctuary. Fortunately these panels come in a wide variety of textures and colors that will allow them to do their job without making the sanctuary look like the inside of a recording studio!
I should say that I am flattered that this is even an issue—someone’s actually complaining that they CAN’T hear the preacher! Wow!
But mainly I want to say that this is a known issue. We are working on it. It is VERY complicated—more so than I’ve described in the summary here. Our sound guys are not to blame. Turning up the volume can actually make the problem worse. Changing the speakers alone won’t fix the problem. A new sound board won’t fix it. But your patience and understanding can help as we continue to evaluate the problem. Once the best solution is identified, we will begin taking steps to implement it….promise.