Boxoffice-April.07.1958

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SOUND TROUBLE EASILY CORRECTED
Continued from preceding
page
dirty exciter lamp will also cause a loss
of volume and poor quality sound reproduction.
Clean sound lens with a soft lens
tissue.
Amplifiers should always be turned on
at least 15 to 30 minutes before show time.
If meters are part of the amplifier equipment,
one can check tubes and get a good
idea whether the circuits and tubes are
working normally and ready for operation.
Make sure the tubes fit snugly in their
sockets. Keep a spare set of tubes on hand.
Some sound systems are not pro\ided with
adequate facilities. If the equipment does
not include meters for checking individual
plate currents of tubes, the projectionist
will do well to have a reliable radio serviceman
come in and check the tubes at
least every two weeks. This precaution
may prevent a number of breakdowns, and
the cost of such service is negligible.
HAVE VOLTAGES CHECKED
The serviceman can also easily check the
voltages at the tube elements, if you have
a fairly late amplifier which makes it
simple to get at the sockets. The correct
voltages must he maintained for maximum
performance of your sound system. If you
do not have these voltages, your radio
technician can check with his tube manual,
which will give approximate "right" values
for your sound system. Voltages vary for
different makes of sound systems, but only
slightly. You can depend on the tube manual
for recommended voltages. Wc do suggest,
however, that you obtain tlie correct
voltages for the various tube elements, and
power supply, from your local supply dealer,
engineer or manufacturer. Likewi.se, schematics.
In some equipment, the schematics
and component values are pasted inside of
the lid of the unit or amplifier. This is as
it should be, in my opinion.
A HAPPY MEDIUM
Good monitoring of sound is very important
to the enjoyment of the patron.
There is a tendency to feed excess volume
in the auditorium, regardless of whether
the house is only partly filled or full. Too
much volume is very irritating to those
with average hearing, but there should be
sufficient volume for those who cannot hear
so well. One should try for a happy medium
in volume and then mark places on
the fader for various settings for a few
people to a full house; then judge the
sound via the monitor. I recommend a
good projection room speaker if you want
better somid and correct volume in the
auditorium.
Finally, we are presenting, with this
article, some data on how easy it is to
build your own test equipment, even though
you do not have an extensive background
of electronics.
Light Caravan on 60-Day Tour
Of Nation's Film Centers
To Demonstrate Lamp
Featuring the blown arc lamp based on
a new principle of producing .screen lighting
up to 65,000 lumens, the Strong Caravan
of Light is on a 60-day tour of the
nation's film center cities to demonstrate
'The World's Most Powerful Light Source."
The tour opened March 17 at the Bel- Air
Drive-In, Detroit, with area exhibitors,
projectionists, dealers and reporters present
to watch contrasts between screen
lighting provided by the touring equipment
and the permanently installed equipment
at the Bel-Air, the same film prints being
used by both projectors for fairness of
contrast in changeovers.
The Strong Light caravan consists of a
large truck equipped as a mobile projection
booth, with motion picture projector, the
new arc lamp, power conversion trans-
A MOST
%A^.
Strong's mobile projection booth which is touring
the country, giving demonstrations in large drivein
theatres of the new Jetorc lamp. From left, are
Ray Shuff, traveling lATSE projectionist; Harold
Brown, soles manager, and Arthur Hatch, president
of Strong Electric Corp.
Since the only light which con reach your screen
must be reflected to it by the lamphouse mirror, the
brilliancy of your projected pictures is dependent
directly upon the condition of that reflector.
All reflectors gradually deteriorate. A drop of
only 10% in reflective efficiency results in a 10%
decrease in screen brilliancy and represents a loss
amounting to 10% of the cost of your current and carbons. Hence, the cost of regular
mirror replacement is truly insignificant.
Silvered gloss mirrors reflect maximum light with o minimum ei h*ot at the
aperture.
Genuine National Precisian Gloss Reflectors ore available for all types and
makes of arc lamps.
n DISTRIBUTED BY NATIONAL THEATRE SUPPLY COMPANY
A SUBSIDIARY OF
formers, rectifiers and water cooling devices.
Ray Shuff, lATSE projectionist,
ojjerates the equipment at all demonstrations,
which are held, so far as possible
in each area, at the drive-in having the
largest screen.
Since the blown arc lamp delivers up
to 65,000 lumens, it obtains a brUliant picture
with evenly distributed illumination,
depth, detail and sparkle on even the
largest outdoor screens. Drive-in exhibitors
witnessing the demonstrations see In the
new type lamp a means of starting their
summer shows as much as a half-hour
earlier, overcoming one of the handicaps
of daylight savings time in many regions
where the first show has not been possible
until too late for volume business.
The blown arc lamp is based on a newly
developed technique in carbon biu-ning
that forms a three-dimensional cylindrically
shaped arc source, permitting the use
of an optical system of much higher efficiency,
Including the largest main reflector
ever placed in regular production.
50
The MODERN THEATRE SECTION
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