i believe ac3 is dolby
c and p from sony
Differences between AC3, 5.1, Dolby Digital, and DTS sound types.AC 5.1 is a generic description of a multi-channel sound system. All of these surround sound types use 5.1 channel decoding to provide surround sound. The 5.1 channels are as follows:1. Left Front2. Right Front3. Center Channel4. Left Rear5. Right Rear6. LFE (Subwoofer)AC3 is a compression technology term, which is used in place of Dolby Digital. It is essentially Dolby Digital.Dolby Digital surround sound is compressed which allows more audio information to fit on a DVD disc.DTS surround sound is an alternate AC 5.1 surround sound which DTS states is not as compressed as Dolby Digital.