An electronic device for converting a multi-channel audio file to a dual channel audio file and vice versa. The multichannel audio file includes a right channel group and a left channel group of channel signals. The electronic device respectively mixes the channel signals of the right channel group and the left channel group according to a mixed matrix to form N mixed signals, and cross embeds the N mixed signals to from a left channel audio signal and a right channel audio signal to compose the dual channel audio file. The electronic device samples, recombines and decodes the left channel audio signal and the right channel audio signal according to a decoding matrix, which is the inverse of the mixed matrix, to revert to the original multi-channel audio file.