Home Theater Tutorial
- What is DTV?
- What is the difference between Digital TV, HDTV, and SDTV?
- What is HDTV?
- What are the visible differences between HDTV and our present
television system?
- Why should I buy a HDTV if there are no Digital signals in my
area?
- I heard that analog TV signals will be "shut down"
in 2006, is this true?
- Can I get DTV over cable?
- What is Digital Cable?
- What cable channels offer High Definition programming?
- What's the difference between digital cable and digital television?
- What's the difference between Direct TV or the Dish Net and
Digital Television?
- Will my video tapes work?
- Will I be able to record the digital signal?
- Why Plasma TV Monitors are Better?
- What are my options for sound with a plasma TV?
- How do Plasma TVs work?
- When are Plasma TVs used?
- What is the plasma in plasma tvs?
- How far away from the plasma should I be?
Q:
What is DTV?
A: Digital Television, or DTV, is a bigger technological advancement than the
shift from black and white to color in the 1950's.
The analog system of broadcasting that we've had in place for over 50 years is
becoming digital.
Since DTV is transmitted as bits of data, instead of analog signals, the images
on DTV sets can be near picture-perfect - no static, snow or ghosting. And DTV
enables a quantum leap to High Definition Television, or HDTV, and interactive
television features.
HDTV provides a superior, wider picture,
with unprecedented resolution and clarity. DTV also provides better sound quality
because it is broadcast in CD quality Dolby Digital® Surround Sound, just like
movies in the theater and on DVD.
While better picture quality and sound have been sought after for over a decade,
the real impetus began in 1996, with a mandate by the FCC, which recommended that
today's NTSC standard be replaced by a new DTV standard called ATSC. By 2003 all
stations are required to be broadcasting in DTV. The next milestone is 2006. If
85% of U.S. households have converted to Digital TV, the analog systems will be
shut down.
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Q:
What is the difference between Digital TV, HDTV, and SDTV?
A: Digital TV (DTV) is the umbrella term used to describe the new digital television
system adopted by the FCC in December 1996. DTV in its broadest terms includes
High Definition Television (HDTV), Standard Definition Television (SDTV), and
a host of other potential applications. HDTV defines certain minimum performance
attributes that deliver approximately twice the resolution of current TVs. SDTV
refers to a system that provides a display resolution lower than that of HDTV.
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Q: What is HDTV?
A: HDTV (High Definition Television) is an entirely new way of transmitting and
receiving a television broadcast signal. HDTV is Digital TV that displays a wide
screen image at 720P or 1080i quality. HDTV broadcasts transmit up to six times
the information as the old analog TV system, delivering higher quality picture
and sound. Current television pictures are made up of 525 interlaced lines scanned
horizontally. HDTV pictures are created by 1080 interlaced or 720 progressive
scan lines, containing up to 2 million pixels (small dots that create a cleaner,
more detailed picture). Ordinary TV displays about 300,000 pixels.
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Q: What are the visible
differences between HDTV and our present television system?
A: Your current TV set is probably almost square, with a 4 to 3 screen ratio.
HDTV screens are about one-third wider than existing TV screens (16-to-9 ratio),
which is more like the aspect ratio of a movie screen. Because of the added width,
HDTV screens more easily match the peripheral vision range of the human eye, making
it more natural to watch.
Next, you will notice the pictures are clearer, crisper and more detailed, involving
the viewer in an almost three-dimensional feeling. You can actually see details
you missed while looking at them in real life. Complimenting the amazing quality
of the pictures is superb sound. With 5.1 channels of audio, HDTV delivers CD
quality surround sound: front speakers on the right, center and left, along with
two back speakers and a sub-woofer.
Unlike HDTV, the present analog system signal suffers degradation as it travels
from the antenna site. Viewers often see double images or "ghosting" and very
poor picture quality. With high definition, the picture is always studio quality,
whether the viewer's television set is located six miles or sixty miles from the
antenna.
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Q:
Why should I buy a HDTV if there are no Digital signals in my area?
A: Today, approximately 50% of the total TV markets are receiving DTV signals.
This will rapidly encompass virtually all TV markets over the next 2 years.
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Q: I heard that analog
TV signals will be "shut down" in 2006, is this true?
A: 2006 is a "target." In Washington, Democrats and Republicans want to balance
the federal budget by the year 2004. Auctioning the analog spectrum has become
a mantra for politicians as one method to help offset a portion of the budget
deficits. In reality, few people really believe that DTV penetration by 2005 will
allow the shutting-down of the analog signals by 2006. Federal legislation approved
in 1997 allows for a continuation of the analog signal in markets where penetration
of digital sets is less than 85 percent.
Even though the budget is a politically explosive issue, broadcasters are committed
to making huge investments to protect their existing franchises.
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Q. Can I get DTV over
cable?
A: On February 23, 2000, The Consumer Electronics Association (CEA) and the National
Cable Television Association (NCTA) reached voluntary agreements that detail the
technical specifications that will enable consumers to receive DTV programming
and services over cable systems.
The technical ability to pass HDTV signals is important because networks that
broadcast HDTV expect the full quality of their pictures to be retransmitted by
cable operators.
The cable operators will also provide carriage of the Program and System Information
Protocol data, or PSIP, that allows for on-screen guides, including virtual channels,
program name, descriptions, DTV format information, and content advisory information.
This agreement is important for the future of DTV because two-thirds of Americans
receive broadcast television programming via cable. However, the agreement does
not mean that every digital signal broadcast by every station will be carried
on cable. The "must carry" rules for the DTV signals that cable systems are required
to carry are still being worked out.
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Q: What Is Digital Cable?
A: Unlike over-the-air DTV, where the digital signals are superior to standard
television signals, digital cable is simply a method of digitally compressing
analog television so that the cable systems can offer more channels. Being digital
also allows cable systems to offer two-way interactive capabilities, like E-Commerce,
online videogames, and other data services.
Broadcasters must follow the federally
mandated ATSC digital television standards for quality and the broadcast signals
are designed to be displayed on DTV sets. Cable systems can choose any digital
standard they wish to save channel capacity and their signals are designed to
be shown on traditional analog sets. Broadcasters must follow the federally mandated
ATSC digital television standards for quality and the broadcast signals are designed
to be displayed on DTV sets.
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Q: What cable channels
offer High Definition programming?
A: ESPN, The Discovery Channel, HBO and New York's Madison Square Garden sports
network have all committed to using HDTV. The satellite services DirecTV, and
The Dish Network have also announced plans for their own HDTV channels.
And with the recent technical agreement between the Consumer Electronics Association
- CEA, and the National Cable Television Association - NCTA, more and more local
DTV stations will begin appearing on cable systems in the near future.
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Q:
What's the difference between digital cable and digital television?
A: It boils down to this: DTV means improved picture and sound. Digital Cable
means more channels. Cable operators will need to find a balance between program
choices and higher definition programming. name=18.0>18. Will it work with all
my other video gear?
Just like conventional televisions, digital TVs are sold with a wide variety of
features. However, because manufacturers understand that people have many different
video devices, most DTV sets have multiple inputs in order to accommodate multiple
devices.
They understand that VHS, DVD, cable, satellite, and broadcast DTV may all have
to be displayed by a single DTV set.
However, it's a good idea for consumers to know exactly what kinds of devices
they want to connect so that they can make sure the DTV set they purchase has
the type of connections they need.
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Q:
What's the difference between Direct TV or the Dish Net and Digital Television?
A: Digital Television, including HDTV, received over the air is FREE.
Like cable, Direct-to-Home satellite networks are not free. You pay a monthly
subscription fee. DirecTV and The Dish Network are the nation's two leading Direct-to-Home
satellite networks. Like cable, both package a variety of channels, including
sports, movies, news, even local broadcast stations, and send them via a digital
satellite signal to rooftop dish antennas on their subscriber's homes.
Digital Television, on the other hand, is transmitted from TV towers, mirroring
today's free broadcast model. Broadcasters must always provide a free signal;
however, the ATSC standard allows them to develop additional over-the-air pay
DTV services if they chose.
DTV broadcasters must also follow the federally mandated ATSC digital television
standards for quality and the broadcast signals are designed to be displayed on
DTV sets. Satellite networks can chose any digital standard they wish and their
signals are designed to be shown on traditional analog sets.
However, both DirecTV and Dish have begun broadcasting some HDTV programs, and
these programs do follow the ATSC standards and must be viewed on an HDTV set
to enjoy the higher resolution picture.
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Q:
Will my video tapes work?
A: Yes. Virtually all DTV sets have video and audio inputs for standard and S-video
machines. In fact, digital sets, because of line doubling and other advanced display
capabilities, often have the ability to significantly improve the picture quality
of pre-recorded video tapes .
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Q:
Will I be able to record the digital signal on VHS?
A: Right now, VHS is limited to the analog signals of conventional broadcasting
or the signals from the NTSC video out on your DTV set, which have been converted
to analog.
So while you can't record the digital signals themselves, you can record a
high quality analog signal coming out of your digital set.
If this digital signal is HDTV, what you record on VHS will be letterboxed or
altered in some way to fit the smaller dimensions of a conventional television.
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Q: Why Plasma TV Monitors
are Better?
Higher resolution
Plasma display devices have higher resolution than conventional TV sets, and are
capable of displaying full HDTV and DTV signals as well as XGA, SVGA and VGA signals
from a computer. For example, you can get plasma displays with a 1024 x 1024 pixel
high-resolution that can display images at true 1080i and 720p HDTV resolution,
as well as 480i and 480p HD signals.
No scan lines
Conventional CRTs use an electron beam to scan the picture tube from top to bottom
at regular intervals, lighting the phosphors to create the image. In the case
of standard (NTSC) TV, visible scan lines can be seen.
Most plasma displays include built-in line doubling
to further improve image quality when viewing standard analog video sources such
as TV broadcasts and VCR tapes.
Exceptional color accuracy
High-end plasma displays are capable of displaying 16.77 million colors -- providing
superb color realism with exceptionally subtle gradations between colors.
Widescreen aspect ratio
Plasma display devices have a widescreen 16:9 aspect ratio, the relationship between
the screen's width and height. This is the proper aspect ratio for HDTV, and also
allows many DVD-Video movies to be viewed in widescreen format, as originally
seen in the theater.
Perfectly flat screen
Plasma display monitors have screens that are perfectly flat, with no curvature
whatsoever. This eliminates the edge distortion that can occur in CRT displays.
Uniform screen brightness
Unlike some rear and front projection televisions that suffer from uneven screen
brightness -- seen as "hot spots" in the middle of the screen or a darkening
near the edges and especially corners -- plasma displays illuminate all pixels
evenly across the screen.
Slim, space-saving design
Plasma display monitors are only a few inches thin-providing installation options
never before possible. In addition to stand mounting, they can be hung on a wall
or from a ceiling, allowing you to enjoy big-screen home theater impact from a
component that doesn't dominate floor space. Conventional TVs and front projectors,
by comparison take up far more real estate and are much more limited in placement
flexibility.
Plasma monitors have an elegant, understated
"picture frame" appearance that blends inconspicuously with any decor;
with a chassis not much wider than the display screen itself.
Because they eliminate the need for a front
projection unit and a projection screen, plasma display monitors are also ideal
for use in a wide variety of business and commercial applications where the use
of a front projector would not be feasible.
Wide viewing angle
Plasma displays offer a viewing angle of 160 degrees (top to bottom and left to
right) -- much better than rear projection TVs and LCD displays. This allows a
larger number of viewers to enjoy proper image reproduction from a wider variety
of locations throughout the room.
Universal display capability
Most plasma monitors can accept any video format. Typically, they will
include composite video (NTSC, PAL SECAM) (standard RCA jacks), S-video and component
video inputs, plus one or more RGB inputs to accept the video output from a computer.
Whether you want to view a sporting event on
HDTV, a DVD-Video movie, a satellite broadcast or even surf the Internet with
incredible big screen impact, chances are a plasma monitor will accommodate your
needs.
Immunity from magnetic fields
Because plasma displays do not use electron beams, as conventional CRT displays
do, they are immune to the effects of magnetic fields. Components such as loudspeakers
that contain strong magnets can distort the picture if placed too close a standard
TV (which has a CRT). On the other hand, plasma displays can be placed in close
proximity to any type of loudspeaker and not experience image distortion.
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Q: What are my options for
sound with a plasma TV?
A: There is only one plasma TV maker that incorporates
built in speakers into the plasma frame (Philips). Most manufacturers do however
offer speakers as additional options which can be attached to the side of the
plasma TV. Amplification of these speakers comes through built in 7 or 8 watt
amplifiers which are built in to the side of the plasma display (this is plenty
of wattage for excellent audio output). Many users will want to attach speakers
to the amplifiers for watching simple programming such as the news or displaying
the unit in a board room or at a trade show.
There are two options to consider here:
- The user may purchase flat, slim speakers which
attach to the sides of the plasma monitor
- The viewer may choose to use his or her own
bookshelf, or satellite speakers. Small cube type speakers may also be attractively
mounted on the wall beside the plasma display TV.
In addition, home users will often use a sound
system with surround sound or their external amplifier/receiver component. Some
manufacturers of plasma TVs offer no built in amplifiers for sound. In this instance
an outboard amplifier/receiver must be used.
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Q: How do Plasma
TVs work?
A: Plasma TVs use thousands of sealed, low pressure
glass chambers filled with a mixture of neon and xenon. Behind these chambers
are colored phosphors, one red, one blue, and one green for each chamber. When
energized, these chambers of "plasma" emit invisible UV light. The UV
light strikes the red, green and blue phosphors on the back glass of the display
making them produce visible light.
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Q: When are Plasma TVs used?
Home Theater
A plasma TV is idea for the home theater enthusiants
who want the best possible picture whilist saving space.
Network Control Rooms
Data and video can be displayed with equal quality
and clarity, allow control room or network managers to constantly view the performance
of their network.
Meeting Rooms
Make your meeting room PC friendly.
Executive Offices
The high tech look will be sure to impress customers,
while serving the dual purpose of making your executives more effective during
meetings and presentations.
Corporate Lobbies
Plasma is the ultimate high tech tool to display
your company's products, services, or events in a visually appealing technology.
Unlike light boxes, which require static duratrans, these flat displays can show
presentations or live video, making for a more informative and effective method
of communicating with customers. You are practically guaranteed to gain their
undivided attention.
Updateable Signage
Plasma's wide viewing angles thin profile and
high brightness has allowed for the concept of digital signs that can be hung
throughout offices, stores, shopping malls, or anywhere you want to share pertinent
video or data to your employees or customers.
Touch Screens
Apply a touch screen to a plasma and you have
a dynamic interactive digital work board.
Light Weight Plasmas
Can be mounted on a rolling stand and shared
between several meeting rooms or offices.
Video Conferencing
Many companies use projectors with video conferencing.
Projectors require dark rooms to produce vibrant images. Video conferencing cameras
require bright rooms to pick up images. These two technologies contradict each
other. Because of its performance in ambient light, plasma is the ideal display
system for video conferencing.
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Q:
What is the plasma in plasma tvs?
A: An electrically neutral, highly ionized substance
composed of ions, electrons, and neutral particles. Plasma contains almost equal
numbers of free electrons and positive ions. In a plasma the electrons have been
stripped away from the central nucleus. Therefore, a plasma consists of a sea
of ions and electrons and is a very good conductor of electricity and is affected
by magnetic fields. Electrons are separated from their respective nucleus when
enough heat is applied.
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Q:
How far away from the plasma should I be?
A: Pixel distortion or motion artifacts can
occur on early generation plasma monitors when displaying an incoming signal with
poor resolution (some cable channels - a signal of around 250 interlaced is generally
poor). However, this "pixelating" effect is lessened by increasing viewing
distance from the plasma display. With early generation models I generally viewed
the proper distances as 8 to 12ft. on a 42" plasma tv and 12 to 16ft. or
more on a 50" plasma. Now, with the many improvements that have been made
to the units, the latest 50" models can be viewed comfortably from 9ft. So
it really becomes a matter of preference. I view a 42" plasma from 16ft.
in my own home and it looks superb.
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© 2001 Pacific Custom Cable Inc
Home Theater Tutorial