A
church’s physical size and structure, as well as
sound requirements for the service, cover a
broad and varied range.
The majority
of churches require some acoustical treatment.
And it is best to hire a trusted outside firm to
handle the job (visit other churches where that
firm has cured acoustical ills). That said,
before hiring an independent professional to do
a thorough acoustical analysis of your church,
it is a good idea to get a ballpark estimate of
what it will take to fix the problems. It can be
done with about $3 worth of party balloons and
some equipment commonly on hand: a camera and
audio recorder. [By the way, dispel yourself of
the myth that acoustical challenges — especially
severe ones — can be cured by console
equalization, or even “room EQ.”] Here’s the
information you need to provide an off-site
analysis of your room acoustics:
Room
Dimensions
This
information allows the calculation of total room
cubic volume, which is necessary to determine
the existing sound absorption and derive the
change needed to reach a desired acoustical
result. Include length, width, height plus sides
and ceiling peak.
Surfaces
What is the
existing composition of the floor, walls and
ceiling? Marble, carpet, wood, drywall, masonry,
acoustical tile, drywall and plaster will all
contribute their unique sound properties to the
acoustical environment. The addition of
acoustical material does not produce a change in
total sound absorption by its full rating unless
the surface being covered is extremely
reflective. If the existing wall has some
absorptive value, a new layer of acoustical
material may provide only a marginal difference
in absorption.
Seating
Is seating
hard or soft? Padded pews will prevent a big
difference in sound when attendance may be down
— during summer vacation, for example. If all
surfaces are hard (marble floors, wood ceilings,
plaster walls and wooden pews) acoustics will
vary more with attendance and season. Heavy
winter coats will reduce echo whereas summer
attire and fewer folks will provide less
absorption, allowing more reverberation.
Capacity
As implied
above, there may be a need to compromise
acoustics between perfect attendance and
vacation time. How many people (maximum,
minimum, typical) attend and how often? Do you
want it to sound good most of the time?
Photos
“Everybody
knows” may be accurate for the regular
congregation’s awareness of the sanctuary and
its furnishings, but it is not good to leave it
to the imagination of others many miles away who
may have worked on some very different worship
spaces prior to your phone call. Pictures will
“flush the buffer” of information stored from a
previous consultation. Six “stills” (front,
back, left, right, ceiling, and floor) will do
the job.
Type
of Service
One size does
not fit all. Moving from traditional choir and
pipe organ to a more contemporary service
modifies acoustical needs. Congregational
singing requires greater ambiance for comfort
while high intensity praise and worship needs
more absorption for control of sound. It is
disheartening to have to add back reverberation
after spending unnecessary amounts of money to
get rid of it.
Current
Problems
What are the
complaints? Is it speech intelligibility or
lifeless music? Often a complaint is given in
the form of a conclusion as to the cause of the
problem. A poll of the non-technical listeners
will sometimes yield better raw input for
acoustics than advice from the regular sound
people who have been doing a work-around for
months or years.
Reverberation
Time (RT60)
This
can be estimated with a loud, sudden noise such
as a balloon pop, timed with a stopwatch from
initial impact until no longer audible. If
recorded, this impulse noise may be viewed and
analyzed on a remote computer screen. Let the
acoustical analyst know where the sound
originates (pulpit, choir loft, center of
sanctuary).
Listening to
the sound and looking at its decay pattern, and
then referencing both to what is seen in the
pictures, will give a good idea of the overall
acoustical sound environment, its causes and
opportunities for correction.
About
the Author...
Nick
Colleran
is a member of the Acoustical Society of
America, Past President of the Society of
Professional Audio Recording Studios (SPARS),
former president of the
Virginia
Production Services Association (VPSA) and is
currently active in acoustical design for houses
of worship, new acoustical products and
performance venues. He is a founding principal
of Acoustics First Corporation, a manufacturer
and distributor of acoustical materials — and
sponsor of the HOW-TO Church Sound Workshop
tours.
