Sound Effects System

A  special sound effects system is a complementing arrangement of both a receiver and several speakers to carry out the acoustic effects while watching a movie. The speakers have to be set up in a certain scheme within the room to achieve best results. The state of the art standard is usually named “Dolby X.X”.

Dolby Surround Systems

The term ‘Dolby’ originally refers to a technology to compress audio and video data that was invented by Dolby Laboratories and nowadays is used as a synonym for the current level of audio processing units in a receiver. The early and very first form of speakers could carry out mono-signals only. That means that it was possible to hook up two speakers, but to both speakers the exact same signals were sent. This way it was not possible to create any audio effects. In the 1960’s a technological breakthrough was achieved when the new audio standard “Dolby Stereo” or “Dolby 2.0” was introduced.

First Appearance of Dolby Stereo

First it was used on the music market only, but very soon the TV and cinema branch made use of it, too. By using Dolby Stereo you still had two speakers, but now each speaker got its own unique audio channel. As a result, first audio effects were made possible: the first audio effects systems were born. After a relatively long stagnation on the market of audio-visual entertainment, the foundation for most home cinemas was laid out in the 1990s. A central processing unit was invented that could split up a stereo signal and subdivide it into four different channels. The “Dolby Surround Sound” standard soon became the nonplus ultra on the home entertainment market. Now the audience got four different sound sources surrounding them while watching a movie in their living rooms: three in front of them (one each side of the TV and one in the centre which was emitting the actors’ speeches) and one in their backs (two small effect speakers that got identical audio feed and emitted background sound effects).

DVD and Dolby Digital

Only the invention of digital versatile discs (DVD) brought it to the next level. With the newly created space for data, the engineers had room to improve the quality of the audio signals further and the “Dolby 5.1” standard became true. Now the two effect speakers in the rear were each actuated with their own channels and a sixth speaker, the ‘subwoofer’ for low frequency effects only, was added.