没有5.1大概是因为你的Receiver没有这功能，你没说清

5.1的数字信号从DVD机出来后由数字同轴音频线或数字光纤输入receiver; receiver decodes, amplifies, outputs to 5.1 analog jacks and drives your 5.1 speakers. Digital coaxial audio cable IS one type of 5.1声道的音频线. Where do you connect the signal output to? Get a 5.1 capable receiver and turn the surround sound on and you will hear 5.1. BTW, I assume you're not using mini home theater system or HT in a box system. Good luck!