Is it possible, that a DVD doesn't have an analog surround channel but just the Dolby Digital sound?
This exact topic has been discussed many times, please use search.Good implementations of MP3, such as LAME, preserve the stereo imaging necessary for the surround information.The amp may do tricks like that, however, people say that it messes up the overall sound.
Well.. I'm not quite sure I understand you. Analog surround sound will not be kept in a compressed format. The AC3 is decoded, first digital pcm, thereafter converted to analog sinewave.
Well, your buddy's amp is guessing when mixing to 5.1, but it may be good at it
But which rules does the decoder follow when handling simple stereo files?
Why the heck does everybody tell something different
In the mean time, if anyone can find a sample which gives audible artefacts using a real surround decoder and sensible speaker placement, I think Frank might be interested.
What's the difference between Pro Logic, Pro Logic II, and Dolby Digital 5.1 Decoding?Dolby Pro Logic is a matrix decoder that decodes the four channels of surround sound from a Dolby Matrix encoded stereo track, such as VHS HiFi tapes, Stereo CDs, and some TV shows. Dolby Surround is a matrix encoding process that in essence combines the Left, Center, Right, and Surround channels onto a single stereo track. A Pro Logic decoder then extracts the four channels on playback. If you listen to a Dolby Encoded soundtrack on a normal stereo system you may notice some sounds appearing to come from beyond the speakers or even from behind you.Dolby Pro Logic II is an advanced matrix decoder that derives five-channel surround (Left, Center, Right, Left Surround, and Right Surround) from any stereo track. It works on any file even if it hasn't been encoded in the Pro Logic II format. On encoded material such as movie soundtracks, the sound is more like Dolby Digital 5.1 (see below), while on unencoded stereo material such as music CDs the effect is a wider, more involving soundfield. Among other improvements over Pro Logic, Pro Logic II provides two full-range surround channels, as opposed to Pro Logic’s single, limited-bandwidth surround channel. This is very similar to Circle Surround.Dolby Digital 5.1 is the latest in multi-channel delivery. 5.1-channel soundtracks can be heard on most movies either on DVDs or in theatres. Dolby Digital 5.1 is also being offered through Window Media 9, digital cable, digital broadcast TV (DTV), and satellite transmissions. Dolby Digital is just that: Digital. It needs to be decoded by a Dolby Digital Decoder. It does not use the same Dolby Surround encode/Pro Logic decode process. Though you can listen to Dolby Digital 5.1 Encoded soundtracks in Dolby Pro Logic via the analog outputs on most DVD Players. Dolby Digital 5.1 is a discrete system that keeps the multiple channels fully separated throughout the encoding and decoding processes. In addition to having full-range Left, Center, Right, Left Surround, and Right Surround channels, Dolby Digital 5.1 soundtracks carry a sixth (“.1”) channel recorded with low-frequency effects (those bass rumbles and booms you feel as well as hear in a well-equipped cinema).
All CDs are stereo, but some could be mastered using one of the 3 Dolby Surround Technologies: Dolby Surround, Dolby Surround Pro Logic, and Dolby Surround Pro Logic II
I've split the post by John Doe containing questions about how to ABX mp3s converted to surround to this new thread.