Acoustical Treatment of Church Overflow Room

I am a systems integrator in Volusia County, Florida and would like a quote from you with regards to treating a space I’ve been asked to fix.

It always amazes me when people spend the money to build a room without any regard to the acoustical consequences.
This is one such room.

This room is approx 60 feet long by 40 ft wide and the side walls go to 23 ft with a pitch up to the center ceiling of 24 ft. The reverb decay time is roughly close to 10 seconds and speech is indistinguishable. The floor is concrete. the ceiling is dry wall and the walls are block concrete.

This room will be used for overflow congregation from the church and also serve as a gym which will be outfitted with basketball hoops on each end.

The first thought in ways to reduce the reverb time would be to treat the wall surfaces with acoustical carpet glued directly to the wall.Secondly deploying acoustical clouds hanging from the ceiling to address floor to ceiling echos.

An alternate consideration would be to line the wall surfaces with 1 inch hard fiberglass (Owens Corning 703) covered with fabric backed with luan or a thin sheet of plywood for rigidity. These panels (4 x 8 ft) would be installed on the walls, possibly starting up at around 7 ft to the ceiling. This alternative would most likely prove costlier than the initial approach.

Please share your insight as to how you’d treat this situation.


Thank you for the E-mail. Wow, that room looks like it was designed to BE an echo chamber! 🙂 Isn’t it amazing that these rooms are built and then the acoustics are considered? For this one, I’ve got a very straight forward approach that has worked in every instance where it was used.

I’ve been asked “How many panels do I need?” enough times that I figured that there had to be a relationship between the size/volume of a room an the number of panels that made people comfortable in that room because in a gym or a swimming pool one might need a few hundred panels but in an office or a classroom one might need only a handful.

Here is the equation:
Cubic volume x 3% = square footage of panels

So, for this room:
60 x 40 x 23.5 (average ceiling height) = 56,400
56,400 x 0.03 = 1,692
This room needs ~1,690 square feet of panels.

I would probably start by installing some kind of acoustical panel onto the ceiling of the room. I really like the ceiling for rooms like this because if they are used as a gym, by the time a basketball gets up there it has probably slowed down pretty considerably. Also, the panels might tend to be a little bit less distracting on the ceiling than they would on the walls. This, however, is just my opinion and the panels can actually be installed anywhere in the room and have the same affect on the space. If the church feels like the walls are a better choice, the acoustical result will be just about identical. For this type of room, we are just looking to “take the edge off” so the exact location is not critical. The square footage is the thing that should be considered the most.

Another thing that I run into all the time for projects like this is that the budget to fix the problem is quite lean, and understandably so. Building is expensive. I usually send out three product samples for churches in situations like this to consider. They include:

Echo Eliminator
Sound Silencer
Fabric Wrapped Fiberglass panels

Before getting too involved in the details, in just about every installation, the Echo Eliminator panels are the panels that people end up purchasing for a few reasons. First is the cost. These are some of the most cost effective, Class A rated acoustical panels on the market. They are also some of the most absorbent. They are not the most aesthetically pleasing panels in the world, nor are they the most abuse resistant, but if they are put on the ceiling or high up on the walls, you are so far away from them when you’re standing on the ground, that you are not likely to notice anyway. Now, when you’re holding them in your hand it’s another story, but people don’t usually consider that, they will be mounted at a pretty significant distance.

The Sound Silencer panels are much more impact resistant, but are twice the cost and half as acoustical. The Fabric Wrapped Fiberglass panels are MUCH more decorative looking and just as absorbent, but they are probably three or four times the cost as the Echo Eliminator panels. Most people who are sitting in a church board meeting looking at samples REALLY want to go with the Fabric Wrapped Fiberglass option, but when they compare the quotes, it’s usually not in the budget.

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