Question re: DVD and DDPLII (1 Viewer)

[Doug Smith]

When listening to a DVD that is less than 5.1, why does the volume decrease even when put ino DDPLII?

 

[Bill Kane]

Doug,

All DVDs come with a Dolby Digital 5.1 English soundtrack. If the DVD is played through stereo (two) speakers, it will downmix into the two channels and there should not be any huge decrease in sound level output.

...why does the volume decrease even when put into DDPLII?

Actually, it's DPLII, or Dolby ProLogic II, a new sound processing scheme designed the enhance two-channel sources in a surround system, like VCR tapes, tv audio. There is no particular reason one would activate DPLII when playing a DVD if one has the full surround speakers set up.

What else is going on here? What makes this seem like a "problem?"

A belated welcome to HTF, and at your leisure, please scan through the "Primer" mini-tutorials located in the HTF Basic board.

bill

 

[Doug Smith]

I do have the full surround setup - but not all DVD's are in 5.1 - I have many that appear to be two channel eg. many old releases like Dogs of War, etc.

 

[Bill Kane]

Yes (that's the problem w/ generalizations) there are older DD 2.0 or 2.1 soundtracks out there; sometimes in 2.0 French on North American discs.

One of the more eclectic is "Tora, Tora, Tora." It comes with English 4.1 Surround/English Dolby Surround/French Mono/THX Optimode.

So what decrease in volume do you experience? Dependent on the older soundtrack mix?

 

[John Garcia]

I have noticed this also, and I have no good explaination for it other than that it has something to do with the processing.

There are a number of DVDs (including in English) that do not have 5.1 mixes on them, because they were originally not recorded that way and were not remastered, or the director/stuido decided to leave it in it's original format.

I have at least two that are mono and just sound funny collapsed into the center and in stereo, but better when played in DPLII or CS5.1.

I just turn it up for these discs.

 

[Marc Rochkind]

OK, well just to be really particular about this, from the DVD FAQ (http://www.dvddemystified.com/dvdfaq.html) I learned that a DVD can have up to 8 soundtracks, and the choices for each are DD, MPEG-2 audio, PCM, DTS, or SDDS. The most common is DD, which can have from 1 to 5.1 channels. (In other words, as was noted above, DD doesn't mean 5.1. That's just one of the choices.)
6.1 is not a unique format for DVDs. The additional rear channel is matrixed into 5.1's two surround channels (similar to what happens with Dolby Surround).
Here is something else the DVD FAQ says about downmixing DD: "The Dolby Digital downmix process does not usually include the LFE channel and may compress the dynamic range in order to improve dialog audibility and keep the sound from becoming "muddy" on average home audio systems. This can result in reduced sound quality on high-end audio systems."

 

[Robert Cook]

Doug Smith wrote:

Quote:

The DVD FAQ gets the details right later, but this quote is misleading. Anyone who needs to downmix their DD 5.1 soundtracks into 2.0 channels is undoubtedly using the DD decoder in their player. It's not the downmix process that compresses the dynamic range, but a non-related feature of DD on your DVD player. Most players default to "Normal" dynamic range compression, which is usually a middle-of-the-road level. This is so that you don't exceed the limited capabilities of your TV's built-in speakers. Many players have a setting that can be changed so that the decoder will apply less or no compression. Dynamic range compression can also be used on full 5.1 soundtracks, so like I said, it has nothing to do with the downmix process itself. Most DD 5.1-capable receivers that I've seen default to no compression at all.

 

[Bill Kane]

As an amateur, I must constantly remind myself not to "advise" beyond my depth. So, Robert, your engineer's specificity is highly welcome and appreciated.

Internet postings in this field, unfortunately, usually start out inductive in which the originator is general and leaves many parameters unmentioned. So we initially respond in kind. It then takes some patience and effort to resolve the actual "problem."

Doug may still come back to further explain what he's driving at, I hope.

 

[Vince Maskeeper]

I'm still confused on what the original poster is even asking.

Is he saying that when he clicks it into DPL2 mode, it gets quieter?

Is he complaining that the soundtracks are too low on his system (even in DPL2)- alluding that he believes DD5.1 is something that is makes sound quiet, thus DPL2 should overcome this?

Is he comlaining that the volume gets louder/softer during the film itself, no matter the processing mode?

I'm seriously confused as to what the original poster is even experiencing- yet it seems everyone has offered some sort of advice... I'm still struggling to figure out what the problem might be...

-Vince

 

[Robert Cook]

Vince Maskeeper wrote:

I'm seriously confused as to what the original poster is even experiencing- yet it seems everyone has offered some sort of advice... I'm still struggling to figure out what the problem might be...

We all are, which is why more information is needed. Some of us just provided a bunch of potential causes and general information, to hopefully help Doug be more specific in telling us what he's experiencing.