Columbia ISA
Audio – Video







Home

Glossary

Basics

Surround Sound

what you need



Speakers

DVD

Models

Connections

Cables





Formats

Features

Television





Home Theater
The History of Home Theater

Renting movies on videotape to watch at home became common in the 1980s. Consumers would drive to the video store and rent a VHS tape to play on their home VCR and watch on their tube TV. VHS movies have  250 lines of video resolution and the televisions had at best 2-channel stereo sound. You could connect your VCR output to your stereo system for more robust audio but still get only stereo sound. Eventually, consumers  looked for better ways to replicate the movie experience in the home. 

To answer the demand, TV manufacturers began to produce TVs with larger screens. Until October 1986, when Mitsubishi became the first manufacturer to offer a 35-inch TV, the largest TV available was 27-inches. The biggest direct-view TV made was 40-inches.

The problem was that a 40-inch screen was about the biggest a CRT (tube TV) could get. In order to get a bigger picture, manufacturers began to experiment with projection and flat panel technology.

The first and most famous of these early attempts at big screen projection TV was the Advent VideoBeam, introduced in 1975. The VideoBeam was a two piece system with three CRT tubes ? red, green and blue ? housed in a coffee-table-sized console with the picture projected on a 7-foot diagonal curved aluminized screen that had to be placed precisely eight feet away. The VideoBeam was designed by audio pioneer Henry Kloss, and its success led Kloss to found his own large screen TV company, NovaBeam.

The first one-box rear-projection televisions (RPTV) appeared in 1982. These large screen TVs used the same CRT projection technology used in front projection systems such as the NovaBeam, but used a series of mirrors to reflect the image onto the rear of a screen. This arrangement allowed RPTVs to take up much less space than front-projection systems. 

In 1988, the first LCD front projector became available. In 1993, in anticipation of the coming HDTV age, RCA unveiled the first widescreen, 16:9 tube TV.

CRT and LCD remained the lone large screen display technologies until 1997 when two new technologies were introduced: gas plasma and digital light processing (DLP).

Gas plasma allowed the creation of large, flat-panel screens measuring less than six inches deep, but could be made larger and produced crisper and brighter images than flat LCD panels. 

Research began in the mid-1960s in Japan by Fujitsu and at the University of Illinois. Commercialization took thirty years, however. Fujitsu unveiled the first color plasma display in 1993. The first high-definition monitor was not unveiled until 1999. But in that short time, the flat plasma display has become the "must have" HDTV.

DLP, used in both front and rear projection TVs, uses a million tiny mirrors to create large, bright images, but requires much less physical space and power than CRT-based rear projection sets and LCD-based front projectors.

Bigger sound also was needed to complete the theater-at-home experience. In July 1983, JVC introduced VHS HiFi, bringing the stereo sound from the theater to the home. But stereo wasn't adequate to simulate the  movie theater experience. In 1982, a four-speaker scheme called surround sound, consisting of two speakers in front and two behind the movie watcher, was developed by Dolby Labs.

Dolby Surround Sound was expanded to four channels (front left, front right, center and rear) and five speakers (the fifth speaker was a subwoofer to supply additional bass) with Dolby Pro Logic in 1987, then to five channels, five speakers (two rear channels rather than one) and a subwoofer with Dolby Digital in 1995, then to six channels with Dolby EX in 1999.

With the introduction of DVD in the late 1990s, with their 480 lines of video resolution and digital surround sound, the integration of higher video resolution, surround sound and large-screen displays completed the attempt to bring the theater experience at home as close as possible to the movie theater.





About Home Theater

Home theater
is one of the hottest things on the market right now - but what is it? Why would you want it? And what do you really need to buy to enjoy it?

Why Home Theater?

Anyone who has enjoyed the visuals of the wide-screen movie, and sonics of movie theater sound knows from experience how much more this experience enhances your enjoyment of a movie than watching the same movie at home on your standard CRT TV set with, at best, stereo sound. 

What if you could have the movie theater experience, but at your home, on your time schedule and under your complete control. What if you could sit in "your" seats and know exactly who your seatmates are and set the air-conditioning to your settings? What if you controlled the volume of sound to your liking and never missed a portion of the movie, because you control the "projector".

Well now you can get fairly close to this. With today's wide-screen high-def televisions and multi-channel sound systems, the theater experience "at home" could rival the old movie theaters.

The goal is to duplicate, in your own home, the surround sound envelopment and integration of picture, drama, and sound that you experience in a commercial Dolby Surround movie theater, only on a smaller scale. The entertainment is for you, and your friends and family. That may sound ambitious, but surprisingly, even a basic home theater system can deliver remarkably enhanced playback of DVD movies, rental videotapes, and even TV shows that are recorded and broadcast in Dolby Surround.

A basic home theater system consists of a pair of front left and right speakers on either side of the TV, a center-channel speaker on top (or beneath) the TV set to anchor the actors dialog at the TV screen no matter where you sit, a pair of smaller surround speakers to either side of your seat that carry all the effects and ambient sound of a movie or TV show-street noises, planes flying, jungle sounds, the noise of rain, thunder, or crickets, distant explosions or rumbles, and all the myriad of other sounds that make up a movie soundtrack, including, of course, the movie score, the music and songs that underscore the action on screen. Lastly, most home theater systems add a subwoofer, typically a square black box that produces ultra-deep bass sounds-rumbles, storms, deep musical bass and the like.

That's a total of six speakers, including the subwoofer, and it comprises "5.1-channel" sound (the .1 is the subwoofer bass channel). But all the speakers needn't be big. Because the subwoofer carries much of the low bass energy, the other "satellite" speakers can be compact and visually unobtrusive, no larger than a hardcover book.

To this mix, you must add a Dolby Digital Surround Sound Audio/Video receiver, which contains all the circuitry to "decode" the DVD or videotape movie soundtrack and effects, plus five built-in amplifiers for each of the five loudspeaker channels (the subwoofer always has its own dedicated built-in amplifier). And finally, you need a DVD player. (You can use a Hi-Fi stereo VCR, but it will only deliver analog Dolby Surround, not 5.1-channel Dolby Digital.) A DVD player could cost less than $100, and a Dolby Digital/DTS A/V receiver can be had for $200 or more.

Bringing Theater Home
"Home Theater" means entertainment systems combining video and audio — pictures and sound — primarily for watching movies, but also television and music videos.

A Basic System Might Include:
    •   TV (traditional or High Definition — but you probably want something larger than a 19 inch screen either way)
    •   Basic VCR and/or DVD player
    •   Surround-sound receiver and six speakers — three across the front, two in back, with a deep-bass speaker (subwoofer) that can be hidden away.

More-elaborate Systems Might Include:
    •   Large screen TV (anything from a rear-projection to a plasma screen)
    •   DVD player — to maximize the audio and video effects
    •   Even more speakers — on the sides, for instance, and even above, for spectacular overhead sound effects.

Why All the Speakers?

Film engineers use sophisticated tricks to convince you that bullets actually are flying past your head — and those tricks (called "steering") are decoded by your surround-sound receiver and sent to each speaker to do magic. That's why it's aptly named "surround-sound." Often you'll see surround-sound represented as '5.1'. Five point one is a term used to describe digital surround sound audio formats such as DTS™ and Dolby? Digital. The five stands for five discrete channels of sound information.

These channels are full-range and fully digital — left front, front center, right front, right rear or surround, left rear or surround. The point one is a sixth channel designated for a subwoofer.

 FAQ - Home Theater
  
     

Question:
What is the difference between the  DTS formats dts-es, dts-es discrete, dts-es matrix?

Answer:
DTS is a digital sound reproduction format that provides 5.1 channels of surround sound similar in concept to Dolby Digital (though somewhat different in execution). The traditional DTS system provides five discrete full-range channels for the front left, center, and right speakers as well as for the rear/surround left and right speakers. A sixth limited bandwidth channel is provided for a subwoofer to produce low bass effects (80Hz and lower).

Recently Dolby and THX developed a new 6.1 channel audio system made famous with Star Wars The Phantom Menace. The new format added a sixth channel in the center of the rear. DTS released a similar 6.1 channel format known as DTS-ES. The new 6.1 formats provide front left, center, and right channels as well as rear left, center, and right channels along with the subwoofer bass effects .1 channel. 

The new rear center channel helps provide more accurate sound effect movement through the sound space. Before the advent of the extra channel any sound from the rear came from the left or right side of the room thus say a starship flying directly overhead from the rear sound as if it came from the left and right sides. The new rear center channel allows sounds to be more localized and directed as they move over and around the audience in 360 degrees.

DTS has provided two 6.1 formats, one fully discrete and one matrixed. With the discrete format each of the six main channels as well as the subwoofer channel occupies its own space on the recorded disc. By contrast, the matrixed format encodes one additional channel into the two rear channels of a 5.1 sound track. This additional channel is later decoded by a special decoding chip. It is not discrete because it does not exist on its own, it is an extra channel coded into two others using a mathematical algorithm (this is how analog Dolby Pro-Logic provides a center channel and rear channel from a two channel recording). Discrete channels are better because there is no channel interaction. Whenever one channel is derived from others there is the possibility for errors and decoding artifacts that muddy the sound quality. 

These problems can be reduced using the right equipment but cannot be truly eliminated whereas discrete channels are completely separate with no encoding or decoding problems possible.

So how big of an impact is the discrete versus matrixed issue for a rear center surround channel? In reality, it does not have that big an impact since this is an effects channel. It is unlikely you will notice much of a difference if any at all in normal listening. In fact, the Dolby/THX 6.1 surround format, THX Surround EX, offers only a matrixed option. 

Furthermore, not many movies yet make use of 6.1 sound (though this is changing and you should prepare for the future if possible). You will need another surround speaker to be placed in the center of your rear wall to take advantage of 6.1 surround sound. Also to take advantage of DTS-ES you will need DVD encoded with the technology. 

DTS, while an excellent format, is not as widely distributed or used as Dolby Digital. You will also need a DVD player capable of passing a DTS signal (some early players cannot though all newer ones should) and of course you would need a receiver with DTS-ES decoding and power for the additional channel.

Question:
How do I connect my cable TV to my home theater system? Do I still run it through my VCR and then straight to the TV? 

Answer:
There are a few ways to connect your cable TV to your home theater setup. If you have an external cable box and it has RCA audio and video outputs, use those (most standard cable boxes do not have a/v outputs, although newer digital cable boxes should). 

If you are not using a cable box you should continue to run your coax TV cable from the wall into your VCR (or DVD recorder) and then out to your TV. To take advantage of your home theater system, however, you will need a set of stereo audio outputs to connect to your receiver. 

Your TV may have RCA stereo audio outputs. If so, run a set of RCA interconnect wires from the audio outputs on your TV to the audio inputs on your receiver marked TV (or whatever source you would like to use for TV). You may need to use your TV's menu system to tell it to use the RCA audio outputs instead of its own internal speaker (consult your owners manual for the specifics on your set). Then when you watch TV, simply set your receiver on the input you connected the stereo audio cables to from your TV and you will be able to enjoy home theater sound (audio) using your cable box.

If your TV does not have audio outputs, you can use essentially the same procedure with your VCR. Connect the audio outputs from the VCR or DVD recorder to your receiver then when you watch TV use your VCR as the source using its tuner to change channels, etc. (your TV will simply act as a monitor). Audio/Video receivers do not have TV tuners in them like VCRs, TVs and DVD recorders do. Therefore they also do not have a coax cable TV input connection. If you can connect the video output (for example, composite or S-Video) of a cable box, VCR or DVD recorder to a video input on the A/V receiver, then you can use the receiver as a switch to select your sources.

Question:
When I connect my television to my stereo, only one speaker works.

Answer:
First of all, make sure you are using the right connections and the connections are not faulty. You should have a pair of RCA cables (white and red) running from the audio outputs on your TV (left and right) to the corresponding audio inputs on your stereo system/receiver. 

Be sure the RCA cables are fully pushed in and there is a solid connection at all four ends. Be sure the right channel (red in most cases) cable is connected to the right (red) audio output on your TV and the right audio input on your music system. Then check that the left channel (white or possibly black) cable is connected to the corresponding left audio output on your TV and the left audio input on your stereo system.

Often the problem you encounter is simply that the cable is not fully seated (connected) to the input or output. You could also have accidentally connected one end of a cable to the wrong input or output so be sure the connections are for the corresponding inputs and outputs (e.g. Audio Output 1 and TV Input 1).

Another problem you may encounter is your TV itself. You need a television capable of stereo to output a stereo signal (if your TV is not stereo capable there should be only one RCA audio output - if there is one). If your TV does not have stereo audio outputs, right and left (usually red and white), then you will not be able to get stereo sound. To produce sound from stereo speakers (left and right) you could use a Y-splitter to split the single RCA cable from your TV into two cables to feed the same mono signal to both channels of your stereo system. 

If you use Dolby Pro-Logic surround sound, this mono signal will come from your center speaker only so put your receiver or pre-amp in stereo mode.

Your other potential problems lie in bad equipment. It is possible that one of your RCA cables is bad. Try switching cables and see if the problem switches channels, if so you probably have a bad cable. You could also have a problem with the outputs on your TV or the inputs on your stereo system. Try switching the cables connections to a different set of inputs on your stereo system to see if the problem persists. Also, be sure your stereo system and speakers work properly with other components as well (CD player, DVD player, etc.). If there is a problem using one of these other sources then your issue may be with a faulty speaker connection.

Check speaker wires and connections on back of receiver and back of speakers. Also if necessary, check TV setup on-screen display menus to ensure TV is in stereo mode and not mono and the proper TV audio outputs are selected. Make sure the proper audio inputs are selected on the receiver.

 

Question:
I have a surround sound system with 5 speakers, stereo TV and Hi-Fi stereo VCR but I do not know how to hook it up properly. At times, sound only comes from the big center speaker and I cannot control the volume ever since I turned the tuner on to listen to the stereo.

Answer:
We should start with the basics. Your surround system should include a receiver. You will want to connect your TV and VCR to the tuner using RCA audio cables. Run a pair of cables from the RCA audio out jacks on the back of your TV to the corresponding RCA audio input jacks on your receiver (they will be labeled TV or Video 1 or something similar). Next, run another pair of RCA wires from the RCA audio outputs on your VCR to the corresponding RCA audio inputs on your receiver (Video 2, VCR 1, etc.). 

You should also run an RCA video cable from the video output on your VCR to the VCR video input on your receiver, and run another RCA video cable from the video output on your receiver to the video input on your TV.

Next, connect up your speakers. Be sure that all the speaker wire is tightly connected and properly routed (left to left, right to right, etc.).

Turn on your TV and go into the TV menu. Find the section on audio and turn off the TV''s internal speakers. You will be using your surround sound system for audio playback instead of the TV speakers. All volume control will go through your receiver and its remote control whether you are watching TV or a VHS tape or listening to the radio.

Once your system is properly set up, you should not run into the problems you mentioned. For future reference, however, it is entirely possible at times for all sound to come only from the center speaker. You can force all sound to come through the center by putting your receiver into mono mode. Assuming it is not set to mono, a mono video tape or TV show will probably play only through the center channel unless you set the receiver to stereo mode (Dolby Pro-Logic routes mono sounds to the center channel).

As far as your problem with volume control after having turned on the tuner (the tuner is used for listening to the radio), this was probably simply a problem of using the wrong remote or having an improper set-up. Remember that you will use your receiver remote control ONLY for volume control, not the TV or VCR remote. You will control the volume for the TV, VCR, radio, etc. through your receiver, which powers your speakers and also provides surround sound functionality.

Question:
How do I connect a DVD player, satellite receiver (DirecTV), broadcast TV antenna and VCR (with both front and rear A/V input & rear A/V output) to my television (with A/V & Coax inputs, but no S-Video input)? I want to connect all together using the A/V cables, not coax cable (except the broadcast TV antenna, of course).

Answer:
You will need some sort of video switching device. The most common and easiest way to accomplish your task is to use a Audio/Video receiver with video inputs and outputs. Simply connect each of your components to the A/V receiver and then run a single video cable from the output on your receiver to the RCA video input on your TV (s-video is better to use when available, especially with DVD, but that is not an option since your TV does not offer s-video inputs).

What do you do, however, if you do not have a receiver or your receiver does not have video switching capabilities? First, you should consider purchasing a good surround sound receiver if you do not have one. A receiver will provide a lot of flexibility with much better sound quality than your TV can provide (the difference between TV sound and that provided by a good receiver and good speakers is night and day). Especially since you have invested in a DVD player and satellite system and receiver would be an excellent purchase. Just be sure it has Dolby Digital processing and enough video inputs to satisfy your needs. You should also look for a receiver with enough S-video inputs for all your sources for future upgrades if you purchase a new TV with s-video inputs. 

If purchasing a new receiver is not an option, then you can purchase an audio/video switcher/source selector. Purchase a switcher with four or more composite RCA video inputs along with stereo audio RCA inputs to match each video input. You will then connect each of your sources to the a/v inputs on the switcher then run a set of wires (audio and video) from the output of the switcher to the RCA video and audio inputs on your TV.

With any option you pursue you actually only need three a/v inputs since your antenna will connect directly to your TV (one each for your DVD player, VCR, and satellite system). However, a fourth input group is a good idea for future purchases such as a video game system or a hard drive video recorder (personal video recorder). If you have a receiver you can run a pair of stereo RCA audio cables from the audio outputs on your TV to a pair of audio inputs on your receiver to enjoy television viewing in surround sound through your home theater system.

Question:
I have connected a DVD player directly to a hi-fi system via an optical digital cable. When playing audio CDs it works perfectly but when trying to play DVDs the speakers on the hi-fi do not work. 

Answer:
It seems your connections must be good since you get sound when playing a CD through your DVD player. Make sure you have the DVD player connected to the DVD input on your receiver. When you play a CD or DVD in your DVD player you should set the receiver input to DVD. So be sure that you have selected the appropriate input when you try to play DVDs - it will be the same for DVDs and CDs played in the DVD player.

If your inputs are correct and you have selected the proper input on your receiver then the next most likely cause for your problem is an improper input setting. Your CD output is in PCM format, while your DVD audio output is most likely in Dolby Digital AC-3 (5.1). You may need to select Dolby Digital AC-3 (5.1) for your DVD player input when playing a DVD (although in most cases your receiver/pre-amp should detect the signal and do this for you). Also, be sure that your DVD is not a DTS DVD, unless your receiver/pre-amp is capable of decoding DTS signals (most DVDs are recorded using Dolby Digital AC-3).

When you play a DVD be sure that the DVD is actually playing. If it is stuck on a menu you may not get any sound. Of course also check that it is not muted.

If you still are unable to get any sound from your DVDs try using the analog RCA audio outputs on your DVD player. You should be able to get sound using the left and right RCA audio outputs from both your CDs and DVDs played in your DVD player. You will want to use the digital output so you can enjoy 5.1 surround sound, but you can test that your player and DVDs are operating properly this way.

There is one other possible explanation, if you have an older receiver/pre-amp it may not be capable of reproducing the Dolby Digital AC-3 surround sound signal being passed by your DVD player. If this is the case, you may be able to set your DVD player to output a PCM stereo digital audio signal through the digital output or you may have to use the analog outputs (RCA white and red) or purchase a new receiver that handles digital surround sound. The digital surround sound bitstream from the DVD audio track has to be decoded before you can hear it and this is the job of your Audio/video receiver.