What Is Home Theater?
FUN! It’s called Home Theater because it uses audio technologies
develop- ed for use in cinema thea- ters. When you watch a film at a good cinema, you become totally involved with what’s happening on
screen. Though this is partly to do with the size of the image, the all-enveloping quality of cinema sound probably contributes more to the
illusion of being there on the spot, witnessing the action first hand- and Home Theater allows you to enjoy the same experience in the
comfort of your own home.
A great deal of effort and advanced technology goes into creating the soundtrack for modern films and TV dramas. The average soundtrack is highly complex, with many different elements (including dialogue, music, special effects, atmosphere and background noises) all carefully balanced to create the right effect.
The surround sound stereo receiver pro- cessor (Dolby Surr- ound) decodes the soundtrack from a stereo (two channel) track.
This more up to date Receiver Pro- cessors can also process digitally en-
coded information in Dolby Digital or DTS and then can enhance it with THX ,then this information is sent to the designated speaker.
To take full advantage of the home theater experience, the centerpiece (television) should be a 16:9
widescreen high definition monitor! This will allow you to see the movie the way the director intended it to be seen, in its true aspect ratio.
Movies are filmed in one of several widescreen aspect ratios, so by having the same display in your home theater you won’t miss any of the
action. With the vast majority of DVD’s on the market formatted in a widescreen aspect ratio, it only makes sense to be able to see the “big
picture” on your television!
As high definition becomes more prominent every day, the widescreen High Definition Monitor makes more sense
than ever. Not only will it give you the astounding picture quality HDTV allows, but it can greatly enhance your DVD viewing experience as
The Audio/Video Source
The most common Media for home theater is the DVD. With over 25,000 titles available, DVD has quickly
overtaken the VHS tape as the more popular format. The reasons for this are many, but the most notable are greatly improved surround
ound capabilities, greatly enhanced picture quality (at least twice the picture quality), and durability.
The DVD disc is generally encoded in
Dolby Digital or DTS to give the listener a true surround sound experience, just as if you were at a quality cinema.
When the A/V receiver is
used in conjunction with a DVD player and a high definition monitor, you are allowing yourself to be treated to an awesome movie watching
NEW High Definition Satellite receivers and High Definition off air , offer the most awesome visual experience imaginable.
3-D Action Comes To Life
The left and right front channel speakers add width to the sound stage, localizing on-screen sounds to the appropriate side of the screen and contributing to the frontal impact when required. Since they carry a high proportion of the audio information, these should also be high performance, wide dispersion speakers capable of projecting a detailed sound image over a large listening area.
Creating the Atmosphere
The surround/rear effects speakers reproduce the ambience of background sounds in Dolby Digital and DTS that contribute so much to viewer involvement and add the all-important front-to-back dimension to the sound image.
Depth and Dramatic Special Effects
The addition of a powered subwoofer to the system delivers the extra bass output you need to experience the sheer dramatic impact of explosions and special effects, as well as adding to the full richness and texture of the soundtrack.
The most misunderstood concept in home theater, THX is not a substitute for Dolby Pro
Logic or Dolby Digital, but a refinement of it. Through a series of equipment standards, licensing arrangements, and design enhancements, THX
(a division of Lucasfilm, Ltd.) seeks to elevate the performance of Dolby surround. How?
Since sound quality can vary wildly from
system to system, the goal of THX is to control all the variables-- room interaction, equipment choice, and software quality-- to ensure a consistently high standard of motion picture playback. THX processors do incorporate Dolby Pro Logic and Dolby Digital, but they also add some tricks of their own. A high-frequency equalizer eliminates brightness from soundtracks originally mastered for large commercial theaters. In order to enhance the seamlessness of the front-to-back soundfield, the rear channel signal is passed through a timbre-matching circuit. Finally, a crossover system diverts low frequencies to subwoofers-- a THX mandate.
Speakers must also be THX approved. Typical “front-firing“ speakers won’t do for the rear
channels: dipolar designs, which radiate sound to both the front and rear, help create a more diffused and ethereal soundfield. The front speakers feature controlled vertical dispersion to prevent floor and ceiling reflection from muddying the sound.
And, of course, each channel’s efficiency, power handling, and frequency response correspond to Lucasfilm guidelines. By scrutinizing every component in the system-- even power amps and wires-- THX strives to bring a realistic theater experience into every home. All THX-approved products carry the THX logo. Dolby Pro Logic and Dolby Digital bring home the groceries and THX puts them away!
Digital Theater Systems has also adapted its surround sound pro- cess for home use. It is a 5.1 system just like Dolby Digital, but since DTS uses less comp-
ression in encoding process, many feel that DTS has a better result on the listening end. In addition, while Dolby Digital is
mainly intended for the Movie Soundtrack experience, DTS is being used in the mixing and reproduction of Musical performances. Many
CD-only players now come equipped with DTS outputs that allow a DTS-equipped amplifier or receiver to decode the DTS signals imprinted
on "select" DTS-encoded music CD's.
Dolby Surround Pro-Logic
The Dolby processor or receiver decodes the soundtrack from a stereo (two-channel) track. It splits the information and sends it to designated speakers. Music, dialogue, and effects are all fed to the two “main” speakers at the left and right of the screen. A center channel, placed above or below the screen, helps lock the voices to the image, even for listeners seated outside the “sweet spot” on the sofa. Another signal is sent to a pair of rear surround speakers located behind or to the sides of the seating positions.
It’s the surround speakers that envelop the audience in ambient sounds, allowing viewers to feel as if they’re really standing at the shore. Each of these speakers receives an identical, monaural input. The subwoofer is added to give you the dramatic impact of explosions and other low frequency special effects.
Since center and rear-channel information is contained in the original two stereo tracks, the decoder synthesizes these signals through a “sum-and-difference” process, with left and right channels added together (the “sum”) to generate the center, and right subtracted form left (the ”difference”) to obtain the rear.
In order to optimize surround sound per- formance, a Dolby Pro Logic decoder-- essentially an application-specific com- puter-- employs "logic-steering" processors whose complex algorithms remove signal redundancies and improve channel sep- aration. At its best, logic steering creates the illusion of a three-dimensional, 360-degree soundfield that puts you smack in the center of the action.
Better than a Boat
The EIA/CEG surveys compared the entertain- ment value of home theater to other recre- ational and leisure products. Here’s the breakdown:
83% say their home theater is a better value than their pool table.
74% say their home theater is a better value than their exercise equipment.
72% say their home theater is a better value than their hot tub.
70% say their home theater is a better value than their motorcycle.
63% say their home theater is a better value than their boat.
56% say their home theater is a better value than their swimming pool.
50% say their home theater is a better value than their camper or RV.