Church Acoustical Design

Posted By on November 30, 2019


Hi everyone, Dennis Foley from Acoustic Fields. Today we’re going to talk about church acoustical
design and some of the variables that churches face with energy and size of the church. So what do we have in a church as a source? Well we have the spoken word, we have the
musical word if you will and a lot of times all of these are reinforced electronically
through amplification. So we have the spoken word and the musical
word and both of the treatment requirements for each one are quite different. This is the problem. It’s trying to get the two scales, the voice
and the music, there’s just a little bit of area where you can shoot for RT-60 times
and speech intelligibility times and some overlap there so that’s why it’s so difficult
with churches, too to get it right. Because the treatment that you use for music
is a little bit different than the treatment that you use for voice. So it’s a balancing act and you have to
be able to balance the spoken word and the musical word so to speak together. So we have a speech intelligibility and a
musical intelligibility issue. Now there’s no such thing as music intelligibility. There is speech intelligibility but not music. But I’m using it in this way to kind of
give you an idea of the two variables that we really have to work with. So keep that in mind. Also we have low frequency management today
becoming an issue in churches. It’s normally not that big of an issue because
we have lots of volume. However, stages in churches today, they have
a lot of bands, they have a lot of sound reinforcement, electronic amplification. So that just adds more energy to the room. And then you have the choir, they could be
up here in a loft, and then you have the congregation which is down here on the floor, okay? And they’re all singing, the choir is singing,
so you have all these sound fields producing energy. And then you could have the stage in the front
here with the band and the PA system, you could have all kinds of energy sources within
the church. So you have to look at the whole picture,
look at the spoken word and the musical word and figure out what’s best for everyone
in terms of hearing everything. So low frequency management on the stage is
a big, big issue today with churches. A lot of times we build the low frequency
management right into the stage itself. You don’t have a lot of free-standing units
sitting around. What’s the big thing with churches? Well, we have lots of volume, we have big
rooms, we have high RT-60 reflection times that we have to work with. So managing those reflections, the most difficult
part. And why? Because you’ve got to use these absorption
and diffusion technologies and you have to treat surface areas. At most churches you’ll have lots of windows,
okay, and they have surface areas that they don’t want to put treatment on because they
like the look of the room itself. Well, it’s always a compromise and you have
to blend aesthetics and performance together all the time. So it’s just a balancing act. So absorption, probably the most favorite
of all treatment, especially when it comes to low frequency management and RT-60 times. So absorption is a good technology to use. Diffusion is a great technology on the rear
wall of churches to reduce that slop back from that rear wall. Very expensive, diffusers are not cheap. So most churches opt for absorption. Here is another system we’ve kind of set
up to help churches. We do the design work for them, give them
the drawings, define the materials that they have to use, the positions the materials have
to be in and then they usually have church members, members of the congregation who have
woodworking skills and would contribute their time and energy to building the units and
doing the installation. So there’s all kinds of programs that we’ve
been working with churches to help them with this cost and you know, we can supply the
materials, you can supply the labor and the positioning and we do all the design work. So there’s a lot of variables that we can
work with here to get you what you need. But the intelligibility issue, the RT-60 time
management always takes surface treatment and it’s always a give and take. You need to cover so much surface area with
so much rate and level of absorption to achieve a particular RT-60 time and then that means
surface area. So you kind of have to give up some of the
surface area in the church to manage the issue so that the spoken and the musical word can
be heard. So that’s our church acoustical design,
kind of in a summary. Let us know if we can assist you with that
in any way. Thank you.

Posted by Lewis Heart

This article has 1 comment

  1. Hi, Just a clarification that may help for some people. I believe when this video speaks to "volume", the meaning is the volume of the room (square footage), not the "volume" of the sound (amplitude). The larger the room, the more easily it can handle low frequency (bass) sound (energy).

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