Surround Sound's Evolution

The clarity of sound is important to many aspects of entertainment. In the early 70's audio technicians embarked on a journey to create the ultimate sound environment. The first product of their labor was quadraphonic. Quadraphonic had four discreet channels that sound would be recorded upon, and then played back. This system did not go very far due to the expense that it entailed. A consumer was obligated to purchase four-channel playback equipment along with special versions of recorded material. An amplifier had to be acquired along with extra speakers. Quadraphonic was exclusively for the reproduction of music.

The first system to focus on the home theater aspects was Dolby Surround. It came about in 1982 and was composed of a three-channel matrix. This was actually the same recording fashion of the common two-channel routine. What made this unique was the incorporation of a third speaker, the matrix, that would add ambience by emitting only the common sounds of the left and right speakers in one that was positioned to the back of the room. Dolby Surround was much more inexpensive to the buyer. All that was needed to enjoy it was a decoder. This system did not need the playback equipment or any purchase of special recordings due to the fact that it was completely compatible with the two-channel industry.

Dolby Surround was expanded on in 1987 with Pro Logic. Pro logic was in essence Dolby Surround plus a center matrix. A problem that was lessened through Pro logic was that of the rear surround channel. The bandwidth was weak and therefore created inferior sound. Pro logic specified and minimized the sounds that were sent to the rear matrix. This is the system that a person finds today by simply watching television with no additions.

The staple of surround sound, Dolby Digital, was launched in 1992. This is the most common Audio format for modern DVD's. It is equipped with five full frequency channels and an LFE. Speakers would be positioned with two being in the front for right and left sounds, a center speaker for mainly dialogue, a left and right rear for sounds that should be behind the audience, and an additional subwoofer for low frequency effects. This had no matrix all 5.1 channels were discreet.

The more advanced surround sound systems are the extended formats known as Dolby Digital (THX) EX and DTS ES. These have an extra channel called rear surround. With the EX series one needs six to seven speakers, a subwoofer, and a compatible receiver or preamp. This is a matrix channel. One step above this is the DTS ES 6.1 Discreet this is the most advanced home theater surround format. It utilizes six discreet channels. It is not as commonly found because it is a bit more expensive than the 5.1.

The greatest Achievement in surround sound is just now in the theaters. It is the SDDS (Sony Dynamic Digital Sound). This revolutionary system actually has use of eight discreet channels. There is no home theater system that is its equivalent.
But as history has shown, it's on its way.

As for the future of surround sound…. One can only imagine.