WHAT IS 5.1 AND 7.1 SURROUND SOUND?

The numbers 5 and 7 correlate to the number of audio channels used to mix the film, music or video game. They also refer to the number of speakers in the home theater system. For example, a 5.1 surround sound system typically has 5 speakers and 1 subwoofer, and a 7.1 system has 7 speakers and 1 subwoofer.