Surround Sound Basics

The major thing that sets a home theater apart from a normal television setup is the surround sound. For an appropriate surround-sound system, you require 2 to 3 speakers in front of you and 2 to 3 speakers to your sides or behind you. The audio signal is divide into multiple channels so that different sound information appears of the different speakers.

The most prominent sounds appear of the front speakers. When someone or something is making noise on the left side of the screen, you hear it more from a speaker to the left of the screen. When something is occurring on the right, you hear it more from a speaker to the right of the screen.

The third speaker sits in the middle side, just under or above the screen. This center speaker is very significant because it anchors the sound coming from the left and right speakers -- it plays all the dialogue and front special effects so that they seem to be coming from the middle of your television screen, rather than from the sides.

The speakers behind you fill in a variety of sorts of background noise in the movie -- dogs barking, rushing water, the sound of a plane overhead. They also work with the speakers in front of you to provide the sensation of movement -- a sound starts from the front and then moves behind you.

But how do all these sounds get divide? This is the job of the audio/video receiver, which is the real heart of a home theater. In the next segment, we will see what this component performs.

Which Surround-sound Format?

In the last segment, we saw that audio/video receivers decipher the surround sound information programmed in video signals and drive the suitable speakers. Various audio/video receivers are equipped to decipher a variety of formats. Nowadays, there are two main sources for home theater surround-sound formats -- Dolby Laboratories and Digital Theater Systems. Dolby Laboratories formats include different versions of Dolby Digital® and Dolby Pro Logic®. Digital Theater Systems has created a range of DTS Digital Theater Sound formats

• Between the two companies, there is a dizzying collection of sound options. So here is what you want to know
• DTS encoding uses less compression than Dolby encoding. It means that DTS sound is more cleared and sharper.

 

• However, DTS encoding is also fewer commonly used on DVDs and television broadcasts.
• Most DVDs have few Dolby sound options, and some also present choices for DTS sound.
• Fortunately, a lot of a/v receivers support a wide range of Dolby and DTS options. When you're choosing a receiver, you should decide two things: whether you want DTS support and how many speakers you want to use for your surround-sound setup. The most ordinary options are 5.1, 6.1 and 7.1 surround, named for the number of channels. The ".1" points out a channel for a subwoofer. The subwoofer channel carries low-frequency sound to give a bass boost and make a rumbling effect for certain special effects sounds, such as explosions and trains. These are the usual speaker setups and formats that will support them:

5.1 (5 speakers + subwoofer)

A 5.1 surround-sound setup contains left, center and right front speakers. It also has left and right surround speakers. Dolby Digital, Dolby Pro Logic II and DTS 5.1 will all carry this format. DTS 96/24 uses a 5.1 channel format to play audio at the equal sampling rate at which it was recorded