Home Theater system ; 5.1 Surround (matrixed Prologic II)

Extracts 5 audio channels from a stereo source:

• Three for speakers at the front - left (L) and right (R) at 22-30°, and center (C).
• Two for surround speakers at 90-110° to the side or rear - stereo surround left (LS) and surround right (RS).
• One low-frequency channel using a sub-woofer (Sub).
• Describes the Dolby Prologic II matrixed Surround systems, with stereo rear surround channels.
• Surround Sound speaker placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. The center speaker should be placed behind the screen (when using projection) or over or under a tv, and as close to ear high as possible. Rear channel speakers should be placed high on side walls, slightly behind the listening position, and should have a di-pole construction.

Home Theater system ; 4.1 Surround (matrixed Prologic)

4.1 Surround (matrixed Prologic)

Extracts 4 audio channels from a stereo source::

• Three for speakers at the front - left (L), center (C) and right (R).
• One for both surround speakers at the rear - mono surround channel (S).
• One low-frequency channel using a sub-woofer.
• Describes the Dolby Prologic matrixed Surround systems, with mono rear surround channels.
• Surround Sound speaker placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. The center speaker should be placed behind the screen (when using projection) or over or under a tv, and as close to ear high as possible. Rear channel speakers should be placed high on side walls, slightly behind the listening position, and can be of smaller size, due to the frequency limitations of the surround channel.

Home Theater system ; 4.0 Surround (matrixed Quadraphonic)

Extracts 4 audio channels from a stereo source:

• Two for speakers at the front - left (L) and right (R).
  
• Two for surround speakers at the rear - surround left (LS) and surround right (RS).
  
• Describes the early matrixed Surround Quadraphonic, Quadraphonic Stereo and other systems.
  
• Surround Sound speaker placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. Rear channel speaker should be placed high on the back wall, slightly behind the listening position, and can be of smaller size, due to the frequency limitations of the surround channel.

Surround Sound Spec

Surround Sound is the concept of expanding the spatial imaging of audio playback from one dimension (mono/Left-Right) to two or three dimensions.

This is often performed for a more realistic audio environment, actively implemented in cinema sound systems, technical theatre, home entertainment, video arcades, computer gaming, and a growing number of other applications.

Many popular surround sound formats have evolved over the years. They include discrete 5.1 Surround sound on DVD-Audio (DVD-A) or SACD (Super Audio CD), ambisonics, quadraphonic, Dolby 5.1 Surround sound, DTS, DVD-Video (DVD-V), and MP3 Surround.

3.0 Surround (matrixed)

Extracts 3 audio channels from a stereo source:

* Two for speakers at the front - left (L) and right (R).
* One for surround speaker at the rear - surround (S).
* Describes the early matrixed Dolby Surround system.
* Surround Sound speaker placement: Three identical speakers placed equidistant around a central listening position.

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Dolby Pro Logic II

A much improved decoding system for Dolby Stereo encoded material and also caters to the decoding of non-encoded material such as regular two channel music. It differs from it predecessor by achieving a more intelligent extraction of the channels, so much so that instead of a single surround signal, Dolby Pro Logic II yields stereo left and right surrounds. For compatibility with movies and other Dolby Stereo encoded material, Pro Logic II has a Movie mode. Because non-encoded material such a music more often than not collapses to center (all the sound seems to come just from the center speaker), Pro Logic II also has a Music mode which works extremely well and can include user access to parameters to customize the sound field.

Surround EX
Dolby Digital Surround EX first appeared in movie theaters with Star Wars Episode I: The Phantom Menace. This system starts from a standard Dolby Digital 5.1 soundtrack but then applies a form of Pro Logic decoding to the two rear channels only, and derives a third surround channel, positioned between the other two. So from a 5.1 soundtrack, Dolby Digital Surround EX derives a 6.1 soundtrack.

This new system first became available to the home market on THX equipment as THX Surround EX because THX co-created the new system. It is now available on non-THX decoders as Dolby Digital EX. Ideally, a soundtrack needs to have been crafted for this system in order for it to sound right. The surround sound information of non-EX encoded tracks can come out predominantly from the center surround channel and lose spaciousness.

DTS ES and ES Discrete
DTS also delivered some 6.1 systems. The first, DTS ES, is in all practicality the same process as Dolby Digital EX in that the playback system applies a matrix decoder to the two surround channels to derive a third between them. DTS ES Discrete on the other hand actually added a sixth discrete main channel. Where as there are precious few Dolby Surround EX soundtracks on DVD, there are even fewer DTS ES and fewer still DTS ES Discrete. That sixth channel has just not been very successful.

Dolby Pro Logic IIx
Dolby Pro Logic IIx takes virtually any source track, be it two channel or 5.1, and yields up to seven channels of sound by employing the latest in matrix decoding technology.

Surround Sound Formats

Dolby Pro Logic
Dolby Pro Logic, like Dolby Stereo in the movie theater, converts two tracks of sound into four channels. In the days of Laserdisc and Stereo VHS it literally was the only thing going. While dated and overshadowed by newer technology, Dolby Pro Logic remains vital: It is used whenever the medium is limited to two channel and may even be used when technology permits more, in order to save space or preserve the artistry of an original audio work.

Dolby Digital

Dolby Digital (also known as the AC-3 Codec) was first made available to consumers on special Laserdiscs. It came into the mainstream when it was chosen as the multi-channel codec for the DVD Video format. It is an extremely flexible codec which can carry from 1 to 6 completely separate and independent channels of digital sound. The full six-channel configuration consists of the front left, center, front right, rear left and right, and the LFE channel (or Low Frequency Effects channel). The LFE channel has a restricted frequency range, while all the other channels are full range (8 Hz - 20 kHz), so the system is often called "5.1".

While two channel CD Audio has about a 1.5 mbps bitstream, Dolby Digital uses as little as 384 kbps in total for all six channels. Obviously, this requires considerable compression of the audio data (about 10:1). Dolby utilizes "Perceptual Encoding" for this process, putting only those sounds that the brain would pay attention to in the sound tracks. This necessitates very sophisticated algorithms (a series of mathematical formulas) to determine what to include and what to eliminate. In practice, the sound quality is spectacular. While initially a very expensive system for consumers, every surround sound decoder on the market now has Dolby Digital as part of the feature set.

DTS

Digital Theater Systems, or DTS, is another 5.1 digital surround sound format, first developed for movie theaters and then later appearing in homes on Laserdiscs. It is now technically an optional format for DVD. The system utilizes a completely different lossy compression codec from AC-3, and only manages a 5:1 compression. The term "Lossy" means that some of the data are lost during compression, and cannot be restored when the bitstream is decoded. This is contrasted to the term "Lossless", which means that the compression codec (the combination of algorithms used to compress and uncompress the digital data) does not throw away any data, and the original data are restored when they are decoded.

There are some who feel that the DTS codec results in better sound because it uses less compression, but because the two codecs are different, the bitrates cannot be compared at face value (i.e., it could simply be that DTS is less efficient than AC-3 as opposed to actually sounding better). We at Secrets have never been able to definitively show that DTS sounds any better than Dolby Digital. Whereas DTS used to come at a premium price, it is now found on virtually every surround sound decoder on the market.

Speakers Of Home Theater

You want to get the best home theater speakers for your money, so there are many things to consider before laying down your cash. Home theater speakers may sound great in the store, but when you get them home they may sound completely different. The best home theater speakers are the ones that sound great in your home.

How can you tell what will sound good at home? Choose the best home theater speakers is by comparison shopping. Listen closely to different home theater systems. If you already have a receiver, make sure you listen to speaker systems through the same kind of receiver, otherwise you may get a different sound when you take the speakers home.

Narrow your selection down to two or three sets of speakers and compare them while watching that DVD that you are familiar with. As the movie is playing, switch between the various sets so you can hear the difference between the speaker systems. This will allow you to pick the best home theater speakers the store has to offer.

Once you bring your speaker system home, consider the acoustic properties of your home theater room. Ideally, it should be acoustically “dead” -no echos or reverberations. This is pretty hard to achieve in a home environment, but if you install wall-to-wall carpeting and cover the windows with curtains, you will improve the acoustics and allow the best home theater speakers to reach their potential.

Projection Screen

Projection screens are installations consisting of blank surface and a support structure used for projecting an image for the view of an audience. Projection screens may be permanently installed as in a movie theater, painted on the wall, semi-permanent or mobile, as in a conference room or other non-dedicated viewing space.

Uniformly white or grey screens are used almost exclusively as to avoid any discoloration to the image, while the most desired brightness of the screen depends on a number of variables, such as the ambient light level and the luminous power of the image source.

Flat or curved screens may be used depending on the optics used to project the image and the desired geometrical accuracy of the image production, flat screens being the more common of the two. Screens can be further designed for front or back projection, the more common front projection systems having the image source situated on the same side of the screen as the audience.

Home theater projection screen displaying a high-definition television image.Different markets exist for screens targeted for use with digital projectors, movie projectors, overhead projectors and slide projectors, although the basic idea for each of them is very much the same: front projection screens work on diffusely reflecting the light projected on to them, whereas back projection screens work by diffusely transmitting the light through them.

Projector

A video projector takes a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. Video projectors are widely used for conference room presentations, classroom training, and home theater applications.

Video projectors may also be built into cabinets which use a rear projection screen to form a single unified display device, now popular for "home theater" applications.

The cost of a device is not only determined by its resolution, but also by its brightness. While most modern projectors will provide sufficient brightness at night or under controlled lighting such as in a basement with no windows, a projector with a higher lumens rating is required for a room with a higher amount of ambient light. A rating of 1000 to 1500 ANSI lumens or lower is suitable for smaller rooms with controlled lighting or low ambient light. Between 1500 to 3000 ANSI is suitable for medium sized rooms with some ambient light or dimmed light. Over 3000 ANSI is appropriate for very large screens in a large room with no lighting control (for example, a conference room). Projected image size is also important, as the total amount of light does not change, as size increases, brightness decreases. An increase in a widescreen image from 80 inches diagonal to 100 inches diagonal reduces the image brightness by 35 percent.

LCD TV

LCD technology is based on the properties of polarized light. Two thin, polarized panels sandwich a thin liquid-crystal gel that is divided into individual pixels. An X/Y grid of wires allows each pixel in the array to be activated individually. When an LCD pixel darkens, it polarizes at 90 degrees to the sandwiching polarizing screens.

This cross-polarizing blocks light from passing through the LCD screen where that pixel has darkened. The pixel darkens in proportion to the voltage applied to it: For a bright detail, a low voltage is applied to the pixel; for a dark shadow area, a higher voltage is applied. LCDs aren’t completely opaque to light, however; some light will always penetrate even the blackest LCD pixels.

Liquid crystal display television (LCD TV) is a television using LCD technology for its visual output. This technology is generally TFT. It is contrasted to alternate visual output technologies, such as cathode ray (CRT) or plasma display (PDP TV).

Early LCD television had drawbacks relative to traditional visual display technologies. It displayed fast-moving action with "ghosting" and could be viewed best only looking straight at the screen or from a slight angle. These problems have largely been overcome in recent years, and LCD televisions, along with plasma displays, have taken over the dominant market position worldwide from cathode ray displays.

For a long time it was widely believed that LCD technology was suited only to smaller sized televisions, and could not compete with plasma technology at larger sizes. This belief has been undermined by the announcements of seventh-generation panels by companies such as Sharp Corp. Sony, Samsung, LG Philips and others.

Modern LCD TV sets are geographically universal because they have a multisystem tuner, to display PAL, NTSC and SECAM norms. And they include an electronic (step-down & step-up) transformer that automatically can use 110/250 V AC indifferently and universal grounded adapter plugs.

Risk

Space is an important issue when setting up a home theater. If you dot have a lot of room, a home theater in a box is just what you need. They are really compact and dont take up a lot of space, which is perfect for setting up a home theater in a room designated for something else, such as the family room.


These affordable home theater systems, however, do have some negative characteristics. Their quality is generally not up to par with the kinds of components one can purchase separately. Those who tend to be very sound conscious may be disappointed by all-in-one home theater systems.These systems also lack versatility.


They are designed for watching movies using the included DVD player. You can use them as stereos for DVDs in many cases, but they are not true stereo systems. They are generally very limited with respect to carrying additional inputs or outputs, too. They are, simply, limited systems.Al-in-one solutions also risk complete system shut down in the event of one problem. A single broken cable or one problem with the receiver can render the rest of the set virtually useless. One cannot simply replace on part of the system. It is generally an all or nothing proposition. The lack of flexibility can be frustrating for some.


If you necessitate a full-featured home entertainment system that can continue to grow with technology and your interests, these cheaper systems may be a bad investment.When deciding if an all-in-one solution can work, ones needs must be kept in mind. One must simply know what they want the end result of their home theater experience to be. For some, this will lead to an inexpensive purchase. For others, it will produce a need to buy more expensive and higher quality components. If you are looking for a very simple and inexpensive means of trying out the home theater experience in a limited space, however, all-in-one systems may be the perfect way of doing just that...

All In One

We like having work done for us. This is one of the reasons the all-in-one home theater systems, often referred to as home theaters in boxes are so popular. They reduce effort and confusion by bundling together the basics needed for a home theater system. In its most basic sense, a home theater involves a television, receiver/amplifier, speakers and a means of playing recorded media.

Those with larger budgets and more lofty goals may also set aside a full room of a home for the home theater, including special lighting, highly comfortable seating and other extras. However, before one can run, they are usually required to learn to walk. Those who are only now taking their first home theater steps may want to consider an all-in-one home theater package. These boxed systems involve a set of speakers, a receiver capable of pushing surround sound and a DVD player.

They generally do not include a television or monitory. One can use their own television or buy one separately. A twenty-seven inch television is usually considered a reasonable size for home theater beginners.The all-in-one home theater systems are designed with non-experts in mind.

They assemble and install very easily and anyone capable of interpreting a simply installation manual can have their system up and running in a hurry.They are also a convenient item. There is no need to shop about for separate pieces or to worry about getting all the requisite cabling or connectors. Everything is included in the one box in which everything comes.

Design of Home Theater

Today, home theater implies a real "cinema experience" and therefore a higher quality set of components than the average television provides. A typical home theater would include the following:

• A large, high-quality, display - generally a big-screen television; LCD TV, plasma TV, traditional CRT TV, or a rear-projection TV or possibly a video projector, often HDTV-capable.
• One or more audio/video sources. High quality formats such as DVD or laserdisc are preferred, though old home cinema setups use a stereo VHS VCR. Cable, or C band are also common, as are hard disk based systems.
• An audio system that is capable of surround sound. This usually consists of at least 4 full range speakers with subwoofer for low-frequency effects. Sometimes a specialized decoder is used to allow the playback of newer surround-sound formats.
• Comfortable seating and organization to improve the cinema feel. This might include several comfortable recliners and curtains or subdued room lighting (required for video projectors) to enhance the experience.
• Higher end home theaters commonly also have sound insulation to prevent noise to escape the room, and a specialized coating to ensure correct absorption of the sound in the room.

Home Theater ; General Info

Home theater, also called home cinema, seeks to reproduce cinema quality video and audio in the home. The video aspect usually involves a large-screen and/or high definition television or a projection system with movie screen to project the image on. Quality audio reproduction is usually achieved with a high fidelity surround sound system.

Technically, a home theater could be as basic as a simple arrangement of a TV, DVD, and a set of speakers. It is therefore difficult to specify exactly what distinguishes a "home theater" from a "television and stereo". Most people in the consumer electronics industry would agree that a "home theater" is really the integration of a relatively high-quality video source with multi channel electronics and speakers.

Even if households have the system set up for home theater it is common only to use the speakers integrated within the television rather than to play the sound through the surround sound system. This is because surround sound loses its impact with material which is not recorded in a way suitable for surround sound. Films, drama and sport tend to be optimised for surround sound whereas news and daytime TV provide no particular advantage.

Some home theater enthusiasts go so far as to build a dedicated room in the home for the theater. Such a room is often decorated to resemble an actual cinema, with projection enclosed in a projection booth, specialized furniture, a piano or theater organ, curtains in front of the projection screen or movie posters. These more advanced installations often include sophisticated acoustic design elements, including "room-in-a-room" construction that isolates sound and provides the potential for a nearly ideal listening environment. These installations are often designated as "screening rooms" to differentiate from simpler installations.

Home Theater ; How & What?

Like you, I wanted answers to many questions about home theater system, like:

• What's the best component in a home theater system?
• Can I mix and match home theater components without compromising sound quality and picture brilliance?
• What is the best and most efficient home theater projector?
• How does a home theater projector compare with a receiver on picture quality?
• How to design my home theater room for the best movie sound experience?
• How to get the best audio for my home theater system?
• Where can I find affordable home theater seating and furniture
• What home theater speakers are best?
• How many surround speakers do I need?
• How Many sub woofers works best?
• How to position speakers for the best surround sound experience?
• How do I hook up my home theater system?

These are just some of the questions many people are asking on the topic of home theater.

Home Theater ; Whats more?

It wasn’t long ago that no one had ever heard of a home theater system. They knew about televisions, cable and even VCRs, but the idea of big screen televisions and high-fidelity stereo sound systems were foreign to them.

When people thought about movies at home they probably envisioned watching a badly filmed home movie featuring a 1966 vacation being shot onto the living room wall with a whirring old projector. Times have, of course, changed. Home entertainment technology has changed right along with it, too.

Now that we do talk about home theaters, it is worth mentioning what a home theater really is. It’s an effort to duplicate (at least some aspects) the movie experience usually reserved only for cinema attendees. People use home theater systems as a means of going to the movies without really going anywhere.

Movie screen clarity in picture and sound allows us to observe every little detail as we watch the story unfold. We see actors in detail, and are able to watch them practice their craft as if they were only inches away. It’s not just visual, though. Can you imagine a spaghetti western without that theme song? How frightening would King Kong be without his belly-rattling roar? Hmmm...so bored.

Introduction

Hi every body...

This site is all about 'feel free' hobby and relaxing your mind. Welcome to the incredible world of Home Theater! Shopping for home theater systems can be a huge challenge. Whether you are a beginner or looking to fine-tune your existing system, there are thousands of home theater options to consider.

On this site you can learn about home theater basics, components, installation and all the most popular home theater accessories and enjoy all your digital media, as well as online info. Bring your digital experiences into your high-definition home theater! Enjoyyyy....