Abstract: This invention is related to audio field, providing a method to downmix multi-channel sounds into a 3-channel surround sound. This invention concerns reprocessing of encoded traditional multi-channel signals and downmixing it into a 3.1-channel signal by using the principles of signal distribution and virtualization. Its hardware can be established by adding only one rear channel speaker on the basis of the 2.1 system. When comparing with the current multi-channel systems, the present invention simplifies the connections, cuts the cost, and provides ease of installation and use, and is especially suitable for achieving surround sound effect in family flat-panel TV, 3D TV or car surround speaker, and PC multimedia surround systems.