Lack of audio options on some DVDs

Am finding occasional DVDs with no sound option choices in the SetUp menu or even with no SetUp menu at all. Most have proved to be Dolby 5.1 surround but have wanted to listen on stereo headphones. Many users don't have surround speaker systems either. Am I getting just the L & R front channels and missing the surround info if there is no option to select Stereo? One of them (Moonlight Mile) had some rear channel effects on the phones almost like the pseudo-surround headphones like Sony & AR - how could that be? Wouldn't the processing/equalizing for that screw up the normal L & R channels for 5.1 surround? Is there someone out there who programs DVDs to answer this?

 

If your DVD player is hooked up to your stereo using the regular analog L/R outputs from the back, your getting a folddown (or mixdown) of the 5.1 channels into a fake Dolby Surround compatible output. The DD standard, by the way, throws the .1 LFE channel away in the mixdown - so that if the DD 5.1 tracks put all the bass in the LFE, then the 2-channel version will sound very thin. Some players ignore that and blend the LFE channel into the 2-channel mix, anyway.

But, that's why if you have the option to pick a dedicated Dolby Surround soundtrack and you only have the 2-channel playback capability - do it.

Joel

 

Check out "Dolby Headphone", a technique that Dolby has acquired to make surround sound more realistic on headphones. It is built into recent versions of WinDVD for the PC. It's quite a useful. It converts the 5.1 surround into two headphone channels, with special filtering and processing to make it sound as if you were in a room with speakers.

AKG uses a similar technology in their wireless headphone "Hearo 999". The transmitter device connects to the digital out of a DVD player and generates "virtual" speakers from the DolbyDigital 5.1 signal. I read the sound processor can also be used with other headphones and loudspeakers.

 

Thanks - some good info from all but my question still not quite answered. I know about Dolby Headphone and the AKG. If the fold-down is matrixed stereo, wouldn't it still need some processing to give the sort of pseudo-surround effect we heard on Moonlight Mile on standard wireless stereo headphones?
But my DVD player uses the coax digital connection to my AV preamp (with Dolby and DTS 5.1 decoding) in addition to the analog L & R for playing CDs. Many music DVD videos have only a PCM stereo track - no Dolby option. Could it be the unmarked audio option DVDs of features have separate PCM stereo and DD 5.1 tracks and you just get whatever is hooked up?

 

Matrixed surround uses out of phase components for the rear channels. By a neat coincidence, out of phase sounds seem to come from behind (if they are localized at all), so you get a psuedo-phantom surround effect from a matrixed surround soundtrack in headphones, and in speakers if you're in the sweet spot and don't have too many reflections messing things up.

 

I don't think the fold-down procedure is sophisticated enough to provide matrixed surround over the stereo outputs.

If you send matrixed surround in a 2-channel signal to a headpone, you will need extra processing to create the virtual surround. The AKG devices do that.

Your DVD player does not know what is hooked up to it. Hence it can not select stereo or 5.1 content from the DVD depending on whether you use the stereo outputs or the digital output. If you play a 5.1 disc, you will get the 5.1 data stream at the digital output, and the front left and right channels on the L and R stereo outputs, unless you player folds down the surround (which should be a configurable option). All you can do is tell your DVD player via the setup what kind of speaker setup you have (or whether you use headphone) and then it can make its own decision based on that.