First let’s discover what it is that makes a home theater different and more desirable over the performance of a standard television. When you go to the cinema the sound is much better than at home this is because speakers are placed around the cinema not just at the screen and this results in what is called surround sound. At home the speakers are built into a television and no surround sound effect is achieved and the purpose of a home theater system is to allow us the sensation of surround sound in our own homes. This is achieved by using various speakers placed around the room that provide the required effect. Ideally a good system will comprise of a minimum of two speakers in front of where you sit and again at least two more speakers behind or to the side of your seating. The sound is separated into channels that are sent to each loudspeaker with each channel being different to give movement to the sound, an example of how this works is that of a plane passing overhead the sound would start low at the front only and gradually get louder and as it reached you the sound would come from all the speakers and then only from the rear. The same applies to sound that would come from an object at a particular side of the screen if the object was to the left then the left speakers would produce that sound or on the right then the right speakers would produce the sound. The center front speaker acts to balance the sound produced by the left and right speakers to give even better quality sound reproduction and this is why systems with more than two front speakers are much better than two speaker systems.
Splitting the sound signal into channels for your home theater speakers is done by a device called a receiver which can also be called an audio/video receiver and it’s this unit that does all the work involved in transferring any input signal into vision for your screen and sound channels for your surround sound speakers. The receiver depending on which you buy will be able to facilitate various input devices which can be connected simultaneously and chosen via the receiver’s control panel or remote. These devices can include VHS recorders, DVD players, Blu Ray players, games consoles, satellite TV, sky and any other input that could be used for a television. The receiver will then take the input signal of your choice and convert it into two output signals one which is a visual signal to go to your viewing screen and the other will be an audio signal. The audio signal from the receiver will be split into surround sound channels and amplified before leaving the receiver to go to the respective speaker position. So a good home theatre system would have at least five speakers three of them front speakers and a receiver that is capable of handling all the inputs that you would require of it.