Surround sound is aptly named for surrounding the listener with an acoustic environment that goes past the two-channel stereo experience of yesteryear.
Today’s home-based theatre systems place the spectator or listener within a virtual landscape of sound. In the real world, we experience sound within the context of background noises. If somebody is speaking to us, we would also hear the faint drone of a jet far above, a schoolyard full of youngsters nearby, birds in the trees, and a TV grating from the subsequent room. These sounds are spread across the audible landscape. Surround sound faithfully recreates a complete landscape by sending the right sounds to the right places to simulate an experience nearer to real life. The first incarnation of surround sound was surround sound 5-1, including 5 speakers and one subwoofer for delivering bass sounds. This is also known as Dolby Digital and Digital Theater Systems ( DTS ) sound. Next came DTS Extended Sound ( DTS-ES ) or THX as surround sound 6-1. This surround-sound audio system uses 6 speakers and a subwoofer. The 6th speaker takes the position of center rear to form a rather more complete 3 dimensional soundscape. Surround sound 7-1 adds yet one more speaker to the mix. It takes the rear center channel and divides it in 2, flanking speaker positions for a surrounded rear. While a stereo recording will play thru a surround sound system, the receiver will simply send the left channel to half the speakers and the right channel to the other half. To get the full effect of surround sound, the first recording must be encoded for it. When this is the case, the receiver in the home-based cinema system is able to send precise sounds to particular speakers, making “placed sounds” to build an acoustic atmosphere.
For instance, imagine watching a production in which the main personality is standing on the path when he hears his pal call his name just behind him. He turns to his left and sees his buddy. Watching this flick in surround sound, the friend’s voice will come from the rear left speaker, placing you within the sound track. The larger number of speakers a surround system has, the greater its capability to place sounds where they belong. The difference becomes clear when, as an example, watching a war scene with munitions exploding all around. Surround sound will have you ducking bullets whistling by and jumping at bombs exploding behind your back. Compare that with the whole sound track playing thru 2 front speakers in a stereo system. Surround sound adds authenticity as it places you inside the action of the picture, or in the case of music, on stage with the band encircling you. Surround-sound systems have minimum prerequisites for amperage generated by the receiver. If the receiver is not forceful enough, it will not be in a position to push the sounds thru the speakers with adequate gusto. If the receiver has way more power than the speakers need, it’s going to be really easy to blow the speakers out by incidentally leaving the volume up when powering up the system.
Also , be absolutely sure the receiver supports the kind of surround sound desired. A receiver that only supports 5-1 surround sound will be unable to support 6-1 or 7-1 speaker systems.