Whats the difference between dolby digital and dd 3/2.1?

5.1 and 3/2.1 are the same thing. The "3" refers to the LCRs and the "2" is the surround channels and of coarse, the .1 is the sub. Older gear, like my Marantz 880 AVR showed 3/2.1 Newer gear shows 5.1
If you see just "Dolby Surround" it would be pro logic.
Dolby Digital can be anything from 2.0 ~ 5.1
Dolby Digital EX is 7.1

Dolby Digital can be anything from 1.0 ~ 5.1

DD 1.0 is mono center only

DD 2.0 may be mono or stereo R & L or Dolby Surround matrix 2.0.

DD 3.0 is R, C, L

DD 4.0 is R, C, L, mono surround

I thought that DD EX was encoded as 5.1 with a matrix surround. You have to apply the PL-2X decoder to make that 7.1.

If I don't know a word definition I look it up in the dictionary or dictionary.com . I don't wait to be spoon fed...

Casablanca shows only DD Mono

EX the 6,7 channels are encoded in the surround channels of the 5.1
I could play back EX and dts es thru my old HK 635 and it did not have PL-2X.
EX and PL-2X are not the same thing.

From the Dolby site:

Dolby Digital EX takes the Dolby Digital 5.1-channel setup one step further with an additional center surround channel (reproduced through one or two speakers) for extra dimensional detail and an enveloping surround sound effect.
Feature films originally released in Dolby Digital Surround EX (the cinema version) carry the encoded extra surround channel in their subsequent DVD releases, as well as onto 5.1-channel digital satellite and TV broadcasts. If your home theater system has a receiver or preamp/processor with Dolby Digital EX decoding and speakers to support 6.1 or 7.1 playback, you can hear Surround EX soundtracks as they were meant to be heard, with the increased realism created by the extra surround channel. As in the cinema, with regular 5.1-channel Dolby Digital playback no sonic information is lost (although you'll miss out on the heightened realism).
Current Dolby Digital EX soundtracks contain a digital flag that can automatically activate the EX decoding in a receiver or preamp/processor. For titles released prior to late 2001, however, you need to turn on the EX decoding manually.

Any dvd has DD, its just a matter of how many channels. So when the player reads the info on the disc, then it displays how many channels. And older releases showed it as 3/2.1

When the movie Grease first came out it was only Dolby Stereo. Later they came out with a 25th anniversary edition with full DD 5.1

Yes, they are different things. Dolby Digital is a bitstream that can contain anything from 1.0 (mono) to 7.1. Dolby Surround is an analog format similar to ancient quad formats, that synthesizes surround sound from a 2 channel source.

Zenyatto, why can't you just answer someone's honest question instead of being so confrontational? People come here to learn, not be insulted. Well, most people anyway.

As I said, its all DD, so it has to read the bit stream first to know what is on the disc. And what your AVR is capable of as well. So you are right.

Dolby Stereo is the fore runner of DD, as I said again, when Grease was released (1978) there was only Dolby Stereo. In fact if I remember right the video tape case said "Dolby System". That was the very beginning of everything multichannel.

Dolby Stereo is pretty much the same thing as Dolby Surround. 2 channels of analog audio with a matrix encode that can be used to generate a center and mono surround channel. Backwards compatible to 2 channel analog equipment. Same as what VHS equipment uses.

Dolby Digital is different. Compressed digital signal.

A movie like The Natural was released in Dolby Stereo (analog matrix) in theaters. The DVD is straight DD 4.0 (not matrix).

A movie like Die hard was released in Dolby Stereo (analog matrix) in theaters. For DVD it is now DD 5.1.

DVDs also may have a matix Dolby Surround track carried on DD 2.0. That is a combination of DD (compressed digital) and Dolby Surround (matrix analog content).

DD 2.0 may also be straight mono or stereo recorded on 2 channels.

Dolby Surround used a Dolby Surround matrix encoder.

Surround used another brand matrix encoder (not Dolby).

I only mentioned DD 2.0 because that descripton is very deceptive. It may be mono, stereo or stereo matrix (Surround or Dolby Surround).

Yes, DD EX is 5.1 with a matrix 6th mono channel encoded on the surround channels. That would be 6.1 channels. One or two rear surround speakers may be used, but it is still mono surround (AKA one channel of content).

A PL-2X decode tries to make the rear surrounds stereo if you have a 7.1 speaker setup!

Dolby Stereo is not available in consumer products. The consumer version of Dolby Stereo is called Dolby Surround. Analog format, not digital.


Google is your friend. Matrix is a required term!


http://en.wikipedia.org/wiki/Dolby_Stereo

http://en.wikipedia.org/wiki/Dolby_Surround

http://en.wikipedia.org/wiki/Dolby_Digital

Yeah, not anymore. Dolby Stereo, or Dolby System was used on vcr tapes in the late '70s~ early '80s.

When Dolby Stereo was first used in theaters is was really 4 channel stereo. But mixed down to two channels for vcr tapes. Years later with AVRs and Dolby Pro Logic you could produce mono surround from Dolby Stereo vcr tapes.

One thing people haven't mentioned is that sometimes intro material on dvds and blu-rays is recorded in a different format for some odd reason. Many times trailers or the studio intros are not dolby digital on dvds and many times on blu-rays they are DD until the actual film starts and then they switch over to the HD codecs. Could be what you are experiencing.

OK, let's take a different approach. Forget Dolby Stereo, that's not a consumer format.

Dolby Surround gives a synthesized effect from a two channel source. Picture two eggs made into an omelet; it's bigger than the eggs, but you can never retrieve the original eggs once they've been mixed.

Dolby Digital, on the other hand, is like six (or seven) eggs, each in its own pan. Separate at all times, each with its own channel unrelated to the others.

So yes, Dolby Digital is "better" than Dolby Surround because it's designed from the start as a multichannel format.

As far as "matrix" goes, all that means is that the two-channel material has been recorded in such a way as to assist in the surround effect. Surround can be retrieved from almost any two-channel source, matrix encoding just does a slightly better job.

As I've said b4, there is Dolby Stereo, and it is consumer, I also made mention of the '78 film Grease as being one of those releases, on VHS.
denvertrakker was wrong in saying its not a consumer format. But these days you rarely see it on DVD. As most titles are Dolby Digital multichannel.

The basic Dolby Stereo is an analog 2 channel format with matrix encoding to make it up to 4 channel. It is not a format that is available on DVD. A DVD may have the mutant DD (digital not analog) Dolby Surround (analog matrix) format encoded on it.

VHS is an analog format, and DVD is a digital format.

As far as I know, Dolby Surround and Dolby Stereo are the same thing. Matrix 2 channel analog content that requires a decoder.

Theaters used a Dolby Stereo decoder (analog). Have you ever seen a consumer product that has a Dolby Stereo decoder in it? A Dolby Pro Logic decoder pretty much equates to a Dolby Stereo decoder.

The three earliest consumer decoders:

Dolby Surround L, R, Mono Surround

Dolby Pro Logic L, C, R, Mono Surround

Dolby PL-2 L, C, R, Stereo Surround

Maybe it takes one second to lock into the DD information. There are flags encoded in the content that tells the DVD player and receiver what is encoded on each part of the disc.

The menu section and extras in a typical DVD are not DD 5.1 encoded. You are looking a bit too close anyways if a one second update time for the information display bothers you.

My receiver has a blue LED on it. It only lights up for multi channel sound decoding. DD 2.0 is not multi channel sound. I am not sure if it lights up for a DD 3.1 track. I will have to give that a try.

Hello! That's what it is supposed to do. It makes it idiot proof. Automatic. You have to do nothing and know nothing.

If you want to use a 2 channel "Dolby Suround" sound track, check the audio / language setup menu on the DVD. If one is available select it. Not sure why you would want to do so. A DD 5.1 soundtrack (if available) sounds better.

I own one DVD that defaults to DD 2.0 at startup. Days of Thunder. I have to go into the menu and select the DD 5.1 track. I hate having to do that!

From Wikipedia (not an infallible source, I grant you):

"Dolby Surround' was the earliest consumer version of Dolby's multichannel analog film sound format Dolby Stereo."

In other words, in FILM FORMAT it's Dolby Stereo. On HOME EQUIPMENT the exact same thing is called Dolby Surround. I stand by my original statement 100%.

I'll add the following, in hopes of making it a bit clearer.

If the original theatrical print was in "Dolby Stereo":

1. On VHS or a laserdisc without AC-3, it's "Dolby Surround".

2. On a DVD it would be "Dolby Digital 2.0".

If the original movie was "Dolby Digital" or "Dolby Spectral Surround":

1. On VHS it would still be "Dolby Surround"

2. On Laserdisc it could be "Dolby Digital (AC-3)

3. On a DVD, it would be "Dolby Digital".

The DVD technical standard requires either a Dolby Digital track or PCM. Bear in mind that the Dolby Digital track can be anything from 1.0 to 5.1.

You may have noticed that any DVDs that have a DTS track are thus required to have a PCM track or (very rarely) a DD track also.

DD 5.1 doesn't always sound better. Many live music concert recordings sound way better in 2-channel stereo. Most concerts I've been to are originally amplified using only two channels (L/R). In many cases the original mastering to home video is also mastered to 2-channel stereo. Then some marketing genius decides to add a surround-sound track and all he does is put reverb or echoing sounds into the rear channels thus spoiling a perfectly clean 2-channel mix. Thankfully many of these concert DVDs also have 2-channel PCM sound which sounds about a thousand times better than using the compressed multi-channel Dolby setting for these concert DVDs.

To confuse things ever more Dolby Digital was originally called Dolby Stereo Digital, then it got renamed Dolby Surround AC-3 Digital, finally Dolby Digital.

You seem to be confused re audio format and number of channels as well as the capability of your avr and what it can do to the formats it receives. There are also a lot of video releases with misleading information as to the audio content on the packaging. There is even cases of mis flagged track info on the disc. Based on what you are saying there is some conflicting info. The sales sheets for that dvd says "Dolby Digital 5.1" and "Dolby Digital Stereo". What that means based on the packaging and what you got on the disc maybe different. You also mention PCM is on the disc, that is a 2 channel track that can sometimes be listed by mistake as Dolby Digital stereo. Depending on how your dvd player and sound system is setup. A 2 channel PCM track can also often be treated to a matrix decoder automatically on your avr which might display something like "Dolby Surround" or "Dolby Pro logic" or some such. Switch the settings to 2 channel on the avr, and dvd player's digital output to PCM, it may sound better than that mystery dolby track. I've also seen plenty of releases that say Dolby Digital 5.1, but in fact only have a dolby digital 2.0 channel stereo track. The product you mention is pretty old and I sort of have doubts that it has a 5.1 track.