Two channels of audio information recorded and played back in such a way as to recreate a sound stage giving depth and breadth to audio reproduction. Stereo systems use a left speaker and a right speaker with their own, independent amplification and signals. The two speakers operate together to give reproduced sound a sense of spaciousness. hen a sound is produced from both speakers equally at the same time, the sound appears to be directly ahead. When the sound is louder in the left speaker or arrives sooner in the left speaker, the sound seems to have come from the left. When the sound comes primarily from the right speaker, it seems to come from the right. Variations in sound level and timing allow a stereo system to place sounds across a wide, deep three-dimensional space. tereo contrasts to mono, which uses only one channel to reproduce sound. Mono sound reproduction loses the depth and width of stereo. A good stereo system allows the speakers to disappear and the sound to come forth as if the original source were present in the room. Almost all audio/video components make use of stereo audio and almost all recordings are done in stereo (a recording must be properly done and mixed in stereo to achieve the benefits of stereo technology; a mono recording played through stereo speakers will still come across as a mono recording). he other alternate technology for sound recreation beyond stereo and mono is surround sound. Surround sound uses four or more speakers to create a truly enveloping sound field all around the listener. Surround sound is able to recreate not only a recorded sound or event but the acoustic space it was recorded in. However, surround sound is used primarily in movies and television and much less often in straight audio recordings. urround sound systems use a stereo pair of left and right front speakers along with a stereo pair of left and right rear or surround speakers at a minimum. Most surround systems also include a center channel speaker placed in the front halfway between the left and right stereo pair of speakers, and many systems also include subwoofers to reproduce deep bass.