BEGINNERS GUIDE

 

INTRODUCTION

There's nothing quite like the feeling you get when you're watching a movie in a movie theatre - the huge screen, the impressive sound system and the dim lights. A few months after the theatrical debut, the movie is released on a home format like VHS video for playback on a television / video recorder system. Although this system is good for viewing your favourite films, it is limited when compared to the original presentation in the theatre. Your television is much smaller than the screen in the theatre, and the sound from the televisions' own speakers is lacking the large, room-filling presence that is at the heart of any real theatre presentation.

A movie is a combination of both picture and sound, and to recreate the movie theatre experience in the home the sound and picture must be presented in a way that is above and beyond what a typical television / video combination can achieve. Home cinema is used to enhance the home viewing experience by improving both sound and picture presentation of home video sources.

 
   

SOUND

In its most simplest form, the term 'home cinema' is used to describe the addition of a better sound system to a television / video combination. The type of sound system varies depending on what you want to get out of the system, and due to other considerations such as available space and budget. My first home cinema involved connecting my stereo video recorder to my stereo hi-fi amplifier, which allowed me to listen to the soundtracks on videos and TV programmes through two hi-fi speakers positioned either side of the television. The difference between the hi-fi sound and the sound that originally came from the TV's own speakers was an incredible leap, and from that point I don't think I ever used the television speakers ever again (the TV was used as a monitor only, with the volume turned down). Beyond this is the popular home version of the surround sound format known as Dolby Stereo, known as Dolby Surround on home formats. The stereo soundtrack contains hidden information for extra speakers; a centre speaker placed above or below the television, and a pair of rear surround speakers placed to the sides or at the back of the room. Home cinema systems use a Dolby Pro-Logic decoder to separate the extra channels found in a Dolby Surround soundtrack. The next step up from Dolby Pro-Logic is Dolby Digital. This is the high-quality digital surround sound format used in many theatres (and now DVD) that improves on the sound quality of the rear surround channels and also adds a dedicated sub-woofer channel for deep impact bass. Both Dolby Pro-Logic and Dolby Digital require additional amplifiers and speakers for the extra sound channels.

 
   

PICTURE

In many systems, the addition of surround sound alone will have the desired effect for watching movies in the home. But there are other options regarding the television, or monitor, that you use to watch the film. Again, the choice is affected by availability of space and budget, but also on the type of video source you will be using. The general rule is "the bigger the better", as a large screen will reveal more detail and will be closer to the big-screen feel of a real theatre. Televisions come in either the regular 4:3 screen size, or in the 16:9 widescreen format. 4:3 TV's are good for sheer size, while widescreen models take advantage of the increasing number of widescreen sources found on VHS Video, DVD and Digital Television. The picture quality of the presentation is greatly affected by the number of horizontal lines that the video source uses, where more picture lines means better resolution and a better picture quality. As a television screen size increases, the horizontal lines may become more visible, because there are the same number of lines in the vertical screen height regardless of whether the screen itself is 14 inches or 50 inches. At this point it is worth considering the video source you will use. For example, VHS Video has 240 lines resolution, but DVD-Video has 500 lines, therefore DVD is more suited to large screen TV's.

More information about televisions, screen sizes and screen aspect ratios can be found in the Television and Moving Pictures pages.

 
   

BASIC SYSTEM

As I said above, my first home cinema was based around my video recorder which I connected to my stereo hi-fi amplifier. At the time I only had room for two speakers, so this option was ideal. The improvement in sound quality, however, was huge. The full-range hi-fi speakers presented the stereo soundtracks on video tapes and television programmes with a big, wide soundstage that totally exceeded my expectations. I also connected my satellite receiver to the amplifier using a pair of phono interconnects, with the same improvements.

The diagram below shows how this simple system connects together:

 

 

Video To Hi-Fi Connection

There are a couple of things that you need to consider before you connect your video recorder to your hi-fi. Firstly, the video recorder needs to be a stereo model that can read and record tapes and television programmes with a stereo soundtrack. Stereo video recorders will be identified as "Stereo","HI-FI Stereo" or "NICAM" in the UK. These VCR's should have a pair of phono audio outputs on the back, usually coloured RED and WHITE, and are used to send all the sound information to the amplifier. Connecting to the amplifier is done in exactly the same way as you would connect a CD player or radio tuner, and uses a pair of Phono Interconnect Leads. You simply select the amplifier input that the video recorder is attached to, and whatever sound comes from the VCR will be heard through the hi-fi speakers, whether it is a pre-recorded cassette or a pass-through TV signal.

You also need the space to place the hi-fi speakers on either side of the television - placing them anywhere except around the TV will not work and will spoil the whole effect. Place the speakers an equal distance on each side of the TV and the result will be a wider, clearer stereo "soundstage" around the television - it will appear that the sound is coming from the screen rather than from the speaker cabinets.

The speakers should NOT be placed directly beside the TV. Speakers contain magnets which can distort and even permanently damage the screen. Place the speakers at least 300 millimetres (12 inches) from the TV and you'll be OK. There are dedicated home cinema speakers that contain "Magnetic Shielding" to prevent such damage.

If you have a satellite receiver with some audio outputs on the back, and you have spare inputs on the amp, you can connect this too. It connects in the same way, using phono interconnects, and means that you can listen to the sound of satellite programmes without having to have the video recorder turned on.

This system, although basic, is a great improvement over watching normal TV. The next step is to add "Surround Sound". This involves adding extra amplification, speakers and one of several surround sound decoders to the system. You'll find all you need to know in the BUILDING A SYSTEM areas. The term "Surround Sound" is commonly used to describe a home cinema system, as a "true" home cinema has a sound system that uses speakers placed around the room to create a soundstage that surrounds you, rather than coming from speakers at one end of the room.

For information about adding a home cinema to a hi-fi, Click Here.
Alternatively, learn what you need to build a new home cinema from scratch Here

 
   

HOME CINEMA COMPONENTS

Once you've decided to take the plunge and build a surround sound home cinema, you have several options. Generally, the equipment you will need can be narrowed down to a television, video source, amplification, surround sound decoder and a set of speakers. Each component has an important part to play in the overall package. Certain items, such as the sound decoder, may be found as a separate processor, or within a home cinema amplifier, or even contained within the television itself. It may seem confusing at first, but hopefully the descriptions below will help you understand your options a little more. Also, visit the Hardware section for further information about home cinema components.

 
   
 

TELEVISION

It sounds obvious, but you can't have a home cinema without something to watch your movies on. A regular 4:3 aspect ratio television can be anything from 14 inches to over 40 inches in size, but the rule is generally, the bigger the telly, the better the presentation. A 4:3 television over 28 inches is generally accepted as the minimum size for the average, living room based home cinema. Widescreen televisions are commonplace at the moment thanks to DVD and digital TV both providing excellent widescreen presentations, but unless the widescreen set is 32" or larger, a 4:3 picture may appear smaller than on a similar size 4:3 television. More info in the Televisions area.

 

Sony VEGA KV32 FX20U Widescreen Television
   
 

VIDEO SOURCE

This can be any machine that can output both Picture and Sound, such as a video recorder, satellite receiver or DVD Player.

 

Panasonic NV-HD660 VHS Video Recorder
   
 

SURROUND SOUND DECODER

You need one of these decoders somewhere in your system to separate the source soundtrack into the different audio channels needed in a surround sound home cinema system. In most systems, there are either 4 or 6 different channels depending on which Sound Format you are using, with a separate speaker for each audio channel. The decoder separates the audio information required by each speaker. Decoders can be found within home cinema amplifiers and receivers, in add-on processor units, and in some televisions and midi hi-fi units.

 

This Sharp CD-C491H Midi System comes with a built-in Dolby Digital Decoder and extra speakers for surround sound.
   
 

AMPLIFIER

The "decoded" audio channels need to be amplified before being sent to the speakers. In a normal stereo hi-fii system, the amplifier has two amplification sections - one for the left and one for the right speaker. Each of the channels in a home cinema system requires similar amplification, giving rise to the often used name "Multi-Channel Amplifier". There are several ways to amplify the different audio channels, such as a home cinema amplifier or receiver, or a stereo hi-fi amp. connected to a home cinema processor that amplifies the centre and rear speakers.

 
Denon AVR-3300 Receiver
Denon AVR-3300 Amplifier can power five main speakers plus a separate sub-woofer, and also contains decoders for Dolby Digital, DTS and Dolby Pro-Logic surround sound.
   
 

SPEAKERS

You need separate Speakers for each audio channel in your system. The number of speakers is usually five in most systems - three at the front and two at the back. You may add a separate sub-woofer for greater bass presence in most systems.

 

Mission 700 Speaker Package
Mission 700 Series Home Cinema Speaker Package

 

SPEAKER PLACEMENT

A home cinema system uses multiple speakers to reveal the full effect of a surround sound soundtrack. In the most common systems, five "main" speakers are used, while a sixth, sub-woofer, can also be added. Positioning of the speakers is open to trial and error experimentation, but within certain boundaries. The "Acoustics" of every room is different and the sound is effected by room size, furniture, position of the walls, etc., so you should try the speakers in a number of locations to find the layout that sounds the best.

Generally, the Speakers should be positioned similar to the layout shown in the diagram below:

 

 

 

FRONT STEREO SPEAKERS

The two main speakers at the "front" of the room are placed either side of the television. These carry the main action and music audio channels. Looking from above, the distance between the two front speakers should be about the same as the distance between the speakers and the listening position. The speakers should be at about head-height when sitting in the viewing position for the best results.

   
 

FRONT CENTRE SPEAKER

A single speaker that is placed above or below the television. This speaker is used to carry the speech information of the characters on the screen and by placing it at the same location as the television screen, it ensures that your attention is locked onto the picture, making the movie sound much more realistic. It also carries some information found in the front stereo speakers to enhance the overall sound. The front of the centre speaker should ideally be on the line between two main stereo speakers, and at a similar height from the floor, if possible, or above or below the TV is the most common position.

 
JBL TLX103 Centre Speaker
JBL TLX103 Centre Speaker
   
 

REAR SURROUND SPEAKERS

The two rear surround speakers are placed at the sides or behind the listening position. It is the sound from these units that creates the surround sound effect by complementing the sound from the three front speakers. The soundstage then becomes three-dimensional, spanning both from front to back as well as left to right. The type of surround sound you have in your system will effect the choice of speakers you need, with the more powerful digital surround sound formats (Dolby Digital / DTS) needing full-range hi-fi type speakers similar to the two main front units, and Dolby Pro-Logic being able to use smaller, less powerful models.

   
 

SUB-WOOFER

Sometimes referred to as an LFE (Low Frequency Effects) device, a sub-woofer can be added to any home cinema system and is fed only with low frequency bass signals found in big music or action sequences such as gunfights and explosions. When a sub is not connected to the system, the bass information is distributed to the main speakers, but will not have the same deep, wall-shaking sound. Bass is non-directional, so the sub can generally be placed anywhere in the room - experiment to find the position that sounds best. A sub-woofer can be added to any system, while Dolby Digital and DTS have a channel dedicated to driving these boxes for maximum cinematic effect.

 

B & W Matrix 800 ASW Sub-Woofer
 

ADDITIONAL SPEAKERS

Some high-end Home Cinema Amplifiers have outputs for more speakers than detailed above, including additional rear speakers, two centre speakers or multiple front stereo speakers. These speakers are used to create a bigger, wider sounstage around the listener, which is particularly useful for systems in large rooms. They don't carry additional channels of music, they simply distribute a single channel over a wider area.