Although Dolby Surround is relatively unfamiliar to computer enthusiasts, it is not a new concept or technology. It is a patented technology researched and invented by the American Dolby Company for processing theater audio systems. As early as the late 1970s, the company applied Dolby Stereo patented technology to theater systems for 35mm movies, marking the true beginning of multi-channel theater systems. Since then, Dolby has continued to improve and launched a series of audio processing technologies such as Dolby Surround and Dolby Pro Logic for use in cinemas and home theaters.
The core of Dolby surround technology is the 4-2-4 encoding and decoding technology of audio signals. That is, during recording, the original four-channel signals of left, right, center, and surround are synthesized into a two-channel composite signal through a specific encoding method; when restoring the sound, the two channels are synthesized through a decoder. The composite signal of the channel is decoded and restored to the original four-channel signal. The advantage of this is obvious: it is fully compatible with the original two-channel stereo system.