Surround audio has two types: multi-channel and virtual surround

Multi-channel is a sound source for multi-channel programs (Dolby, THX format audio and video or EAX games) using 4 Channel, 5.1 channel, 7.1 channel and other multi-channel speakers sound to restore the sound field

Virtual surround uses delay and phase transformation to simulate a multi-channel sound field from stereo sound sources, through 2 or more channels Sound plays.

Ordinary speakers refer to 2-way stereo (2.0), which has the widest range of sound sources. Surround speakers are stereo-compatible, which means that unmodified "pass-through" mode can be selected when playing stereo sources.