Boxoffice-January.03.1953

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necessary to overcome this difficulty.
Often a slight diversion of the speakers
can cause considerable confusion. I can
recall one instance on an opening night
one of those openings where they roll the
carpet down the aisle as the audience walks
in—the sound had been installed but not
checked. A strike was called by the sound
men, and it lasted for three months. The
acoustics were terrible, and it looked as if
a small fortune would have to be spent to
correct the condition if all walls and ceiling
would have to be covered with acoustical
materials to overcome the defect. The
strike was finally settled and within 24
hours, the speakers were adjusted, no
treatment was necessary, and the house is
one of the choices today for major screenings
of pictures.
AVOID OVERTREATMENT
An auditorium can be overtreated to such
an extent that all resonance is lost—dead
like a violin covered with felt. It will givr
out sound but it has no resonance.
Many exhibitors have insisted on treating
the side walls with a highly absorptive
acoustical material. In most cases, this is
unnecessary unless it is an extremely high
wall or there are some disturbing conditions
such as extreme wall projections or offsets.
However, it is advisable to avoid smooth
plaster on the walls. A fine sand or light
dash finish plaster is always more satisfactory.
The ceiling can always be treated, sometimes
to no great advantage, but never
detrimentally.
The rear wall, especially when of great
height, should be treated with the best
type of acoustical tile or absorbing materials.
The rear wall should not be curved. This
has been the source of considerable confusion.
It has been overcome in some instances
by setting the acoustical material
in a zig-zag fashion.
DIFFERENT VALUES IN
MATERIALS
Acoustical materials have different
values, perforated acoustical tiles generally
have the highest value; soft cane-like tiles
such as Celotex being next in value: with
acoustical plaster generally of least value,
having about 50 per cent the value of cane
fiber tiles or 30 per cent the value of perforated
acoustical tiles. This isn't intended
to condemn acoustical plaster, as my preference
in all cases leans to a recognized
manufacture of acoustical plaster on the
ceiling or where large areas can be covered;
but we still prefer perforated acoustical
tiles on the rear wall, or in any area where
considerable absorption is recommended.
A very satisfactory acoustical material
which has been on the market for several
years is asbeston limpet as it has very high
absorbing qualities, equal to perforated
acoustical tile. It is an asbestos fiber material,
sprayed on, in generally a threequarter-inch
thickness and has the appearance
of a coarse texture plaster. It is very
soft and should be kept out of hand reach.
Ornamental pressed or molded felt panels
Fabrics and draperies have always beert of great value in achieving good acoustics in the theatre. In the
Langley Theatre, Langley Park, Md., the walls are covered with tapestry, a gold-figured fabric on a green
background. The dado is dark green leatherette. The 121 feet of gold-colored, hammered satin draperies
not only add to the luxurious effect but are of value acoustically.
of a deep pattern mounted on furring strips
are highly satisfactory and equal to the
best of acoustical tiles. Many of the broadcasting
stations prefer this treatment.
Fabrics have always been of great value.
Sometimes they are backed with felt, or
even flannel, and when hung loose have a
value equal to the best of acoustical materials.
In many cases, draperies hung at
The dome ceiling
frequently used in
older theatres has
definite
disadvantage
to good acoustics.
A great confusion
of tone occurred
somewhere in
the auditorium, and
usually in the choice
seating. The dome is
to be avoided as
there is no practical
way to solve this
problem except by
covering it entirely
with a highly absorbent
material.
the proper location have overcome trouble
in that area.
The fully upholstered opera chair and
carpeting over heavy padding have been
two of the greatest benefits in acoustical
correction. The difference has often been
very noticeable when new upholstered
chairs have been installed, replacing veneer
back chairs.
BOXOFFICE January 3, 1953 13