During the 1970’s a multi-channel reproduction system was adopted for film. People were accustomed to hearing high quality surround sound in movie theaters and when a similar sound system was combined with home TV’s, it was natural to call the new system home theater or home cinema. At the same time the name home entertainment center became common.


 The heart of the home cinema is a large screen TV set as a monitor. The minimum screen size is 75 centimeters with projector displays being in common use. High quality multi-channel sound, normally Dolby Surround and sometimes THX, is included in the system. In many cases external powerful amplifiers and external HiFi speakers are used. Besides the TV broadcasters, HiFi video cassette recorders and sometimes Laser disk players are included to the home cinema as program sources. A typical home theater system with video and audio program sources is presented in the figure.


 The market penetration of large systems is, however, relatively small. Normally home theaters are physically quite large making it difficult to fit them into a typical living room or any room in a home. Unsatisfactory positioning of the set may also lead to a degraded listening experience. There is an other difficulty. Loud two channel systems are already one reason for many social conflicts in families. In a home cinema there are three or more speakers. Apart from the price, these social reasons may, in many cases, be the ultimate reason why people will not buy a home theater system. However, smaller systems have been sold in relatively large quantities. Also home cinema equipment sets typically have been built up gradually, component by component.

Lucas film has developed THX. Dolby Pro Logic is the basic process for THX. An extra processing have been used for surround channel for creating diffuse and more film like reproduction.