THE BYRD'S PROJECTION SYSTEMS
We have kept the projection equipment as original as possible and
still present a First Class show. This has meant adding some equipment
over the years but always keeping the best of what we have. The
results are a large bright clear picture with excellent sound. All of
our movies are presented in the correct format without cutting the top
or sides of the picture.
TECHNICAL
In the Byrd's booth there are 2 Simplex X-L 35mm projectors each lit by
Carbon Arc lamps. Each projector runs up to an hour at a time requiring
3-20 minute shipping reels of film to fill one large reel for a
projector. During the movie the projectors will switch back and forth
several times depending on the length of the movie. At the Byrd this is
still done by a projectionist watching the cue marks on the film in the
upper right corner of the screen. Each hour of use will use up most of
2 carbon rods, a negative and a positive. These rods generate a very
hot arc of about ¼ of an inch in length using 50-70 amperes of
current. This arc generates enough heat to cause the face of the
positive carbon rod to get as bright as the Sun. (like an electric arc
welder does when welding) The light produced is gathered be a large
mirror and focused onto the film as it goes through the projector.
(Most theatres today use an enclosed xenon arc lamp that often changes color
as it ages.)
To fill our giant 20 x 40 foot screen 110 feet from the projectors we use
Bausch & Loumb lenses with a focal length of about 5¼ inches. We
project the correct format of 1:1.85 for "flat" pictures (most movies)
and 1:2.35 for "wide screen". We also can project the 1:1.33 picture format
that was used for older films - this is the same as the TV format. "Wide
Screen" is achieved by squeezing the picture horizontally onto the film
and then stretching it back out when projected using an anamorphic
adaptor on the front of a regular lens. The width of our screen is
changed by using "legs" - small black curtains on each side of the screen
controlled by an electric curtain motor from the booth. The effect at
the Byrd is dramatic when we go from the regular size picture to wide
screen at the begining of a movie. You will also notice heads are not
cut off as is the case in many of the new theatres with one size "fits
all formats" screen.
16mm Projector
The Byrd also has a 16mm Eiki silent/sound projector with a light
source of a 1000 watt xenon lamp. The format 16mm uses is 1:1.33 and
fills our screen when set to that format. The sound from the 16mm is
fed in to one of our 35mm sound change-overs so that a 16mm short can be
added to the show and switched in and out by the projectionist without
the audience noticing pops or clicks.
SOUND SYSTEM
At the Byrd we use a 4 channel sound system for most films. Three
channels are on the stage: Left, Center, and Right (these 3 channels are
full range) and a surround or "audience participation channel" as it was
referred to in the original Cineamascope system installed in the Byrd in
1953.
STAGE SPEAKERS
Our stage speakers are "Simplex" made by Altec. Each system has a fully
loaded 12 cell horn with 2 drivers designed to cover the full width of
the auditorium and a semi-loaded bass reflex woofer/sub-woofer using
2-15 inch drivers for a total of 36 horn cells and 6-15 inch woofers.
No matter what seat you sit in there are 3 speakers facing you from the
stage thus there are no LOUD spots in the center as in most of the
new theatres that use single cell horns. (You get the feel of real power
without the blast or screech heard in many new theatres!) Our 600
pound/each stage speakers are so sensitive that we rarely exceed a total
6 watts of power to the stage speakers on the loudest of passages!
These speakers have a sensitivity of 115db/watt at 1 meter. Compare
this to the average home or car speaker at <85db/watt at 1 meter. What
this means is that to achieve the same level of sound with a home
speaker when 1 watt is used at the Byrd you would need 1000 watts for
your home speaker! (it would melt down) More power is used for the
booth monitors than is used in the auditorium. Because the power levels
required are so low the distortion is also very low thus true high
fidelity multi-channel sound is heard at the Byrd.
SURROUND SPEAKERS
Our 10-12 inch surround speakers were installed in 1953 as part of the
Cineamascope system. These speakers are also more sensitive than home
speakers but are not nearly as sensitive as the stage systems. (about
95db/watt at 1 meter) We often approach levels of 50 watts to these
speakers.
ELECTRONICS
The sound is picked up off the film by a pair of solar cells mounted
together for left and right channel pickup. Westrex low noise
pre-amplifiers (made in 1943) are connected to the solar cells and feed
a left and right signal to a mixer circuit to derive the center channel.
This provides the front 3 channels. The left and right signals are
passed to a surround decoder to generate the surround channel. The left
and right stage channels also act as sub-woofer channels. This is
accomplished by the use of a special low frequency boost circuit on
those 2 channels only. (This is very effective.) The Center stage
speaker is driven by up to 4-40 watt Simplex amplifiers. We normally
have 2 on for a total available power of 80 watts. The left and right
stage channels are driven by a 80 watt/channel Sansui AV-717
professional DC/DC amplifier. We also have 3-80 watt Simplex amplifiers
that are used for 35mm magnetic sound. (There are still some old prints
of the great musicals with this magnetic sound.) A 60 watt Bogen
amplifier drives the surround channel and is delayed 1/10 of a second so
the listener will always hear the front channels first - as the sound
formats require.
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