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AC-3 Dolby Digital vs 2.0 PCM
https://forum.lddb.com/viewtopic.php?f=12&t=2760		 Page 1 of 1
Author:  graz138 [ 30 May 2013, 18:17 ]
Post subject:  AC-3 Dolby Digital vs 2.0 PCM
I'm sure this topic has been exhausted, but I'm just curious what the consensus is. Does the AC-3 typically sound better or no? Does it sound the same? Just looking for some opinions. I just think it would be fun to use a demodulator to extract the DD even if technically it may be compressed. Thoughts?
Author:  signofzeta [ 30 May 2013, 20:55 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
If you're talking about a 5.1 DD signal versus a four channel matrixed stereo, from my experience the difference is very dramatic. I buy AC3 LDs of movies I don't even like just to experience how great AC3 is.
Author:  laserbite34 [ 30 May 2013, 21:07 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
Hey there. So you don't have Dolby RF demodulator otherwise you wouldn't be asking the question.

Not many RF demodulators, that I can see on ebay at present. Its waiting and waiting for cheap reasonably priced one to come along.

Playing "TITANIC" (1997) Dolby Digital AC-3, THX sound system, presently on disc 2 side 3, it looks better than the bluray and sounds better in my listening opinion having listened to the film, close to over 100 times since its release in early Jan 98.

You won't be disappointed with Dolby AC-3. :thumbup:

Between Dolby pro-logic PCM and Dolby AC-3 that sounds open and wide and keeps effects music and dialouge where it should be with no crosstalk colliding into each separate channel plus the additional LFE.1 that isn't present in 2.0 mix.
Author:  graz138 [ 30 May 2013, 21:48 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
I agree AC-3 should be better. I have a demodulator coming in the mail. In my small amount of research some people were saying that the PCM was uncompressed, so in turn it was "better" which is a loose term I know. The discrete audio is a major plus.
Author:  signofzeta [ 30 May 2013, 23:44 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
It's not compressed digitally, but it is compressed acoustically. Pro Logic doesn't make four channels out of two for free. :)

If it were a mono or stereo movie then PCM 2.0 would be way better. For surround though AC3 LDs are terrific. While the bit rate is low for six channels, keep in mind that there isn't much activity in the surrounds and the LFE only gets %10 of a channel. It doesn't sound like a 90s Napster MP3 or anything. It sounds terrific.

Of course it depends on the movie, some aren't very impressive, but Jurrasic Park, 12 Monkeys, Tenchi in Love, are pretty great.
Author:  disclord [ 02 Jun 2013, 18:25 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
signofzeta wrote:
It's not compressed digitally, but it is compressed acoustically. Pro Logic doesn't make four channels out of two for free. :)

If it were a mono or stereo movie then PCM 2.0 would be way better. For surround though AC3 LDs are terrific. While the bit rate is low for six channels, keep in mind that there isn't much activity in the surrounds and the LFE only gets %10 of a channel. It doesn't sound like a 90s Napster MP3 or anything. It sounds terrific.

Of course it depends on the movie, some aren't very impressive, but Jurrasic Park, 12 Monkeys, Tenchi in Love, are pretty great.


And with AC-3 if any channel is quiet, including the LFE, then those bits are allocated to the channels that are active, so AC-3 can't really be broken down into X-many bits per channel unless all channels are active simultaneously. If sound is coming from only one channel at some point, and all the other channels are quiet, then that active channel is being allocated 384kbps at that moment.

DTS Coherent Acoustics works the same way, with a global pool of bits that get allocated to each channel as needed.
Author:  signofzeta [ 02 Jun 2013, 20:01 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
Yeah, that's what I was getting at. :)
Author:  sdraper [ 03 Jun 2013, 10:10 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
All this said, there are great matrixed ProLogic tracks out there (Batman is both original and definitive and hands down bests every 5.1 remix on DVD/BD) even for 5.1 films later on down the road that had ac3 releases. (Goldeneye, Batman Forever of which the latter has a ProLogic mix that is preferable in areas to the 5.1)

Sometimes there's a choice. For some 70mm releases, I've found that I like the sound of the matrixed LD presentation over a later 5.1 mix. The Criterion 2001 set may not be discrete but it is original, and I somewhat lean towards the PCM 2 ch of Ryan's Daughter versus the DVD 5.1 track.
Author:  signofzeta [ 03 Jun 2013, 17:03 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
Yeah, with movies originally released in 5.1 though I'm going to say that it's a safe bet that 5.1 is usually the best.
Author:  laserbite34 [ 03 Jun 2013, 19:33 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
signofzeta wrote:
Yeah, with movies originally released in 5.1 though I'm going to say that it's a safe bet that 5.1 is usually the best.

Considering how many millions of SR-D prints that have been released worldwide over Dolby surround 7.1, SDDS 8channel with around 200 releases and Atmos with 39 and counting in one year that's not too, bad going at that rate. 70mm with split-surrounds had less that number in year from 1978 to 1979. SDDS 8 had a good start off but soon slowed down.

I still prefer 5.1 and I haven't listened to all the worldwide releases its impossible to catch up even when it started. You have lots of counties using the SR-D India, Japan, France, England, America, south America, Finland Germany and shall I go on...
Author:  Guest [ 04 Jun 2013, 22:17 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
I prefer PCM with neo cinema and not PLII, I only have 1 disk with ac3 tho. but if a disk has 5.1 it's probly you best bet if your using PLII with 2.0PCM tracks
that being said, 5.0 pcm from my pc is the bomb :o (don't have a sub) :thumbdown:
Author:  alien [ 17 Jun 2013, 12:43 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
laserbite34 wrote:
Playing "TITANIC" (1997) Dolby Digital AC-3, THX sound system, presently on disc 2 side 3, it looks better than the bluray and sounds better in my listening opinion having listened to the film, close to over 100 times since its release in early Jan 98.

Looks better then the Blu-Ray? How so? I have never seen anyone claim a LD version of a movie looks better then the Blu-Ray version.
Author:  laserbite34 [ 18 Jun 2013, 15:39 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
alien wrote:
laserbite34 wrote:
Playing "TITANIC" (1997) Dolby Digital AC-3, THX sound system, presently on disc 2 side 3, it looks better than the bluray and sounds better in my listening opinion having listened to the film, close to over 100 times since its release in early Jan 98.

Looks better then the Blu-Ray? How so? I have never seen anyone claim a LD version of a movie looks better then the Blu-Ray version.


The deep blue sea on TITANIC THX LD
Image

Bluary. I think I'm going to be sick with this seasick colour. And can see "the digital blob"around the edges. Oh boy, having seen this projected 14 times and projecting it myself at first screening at Warner village in 1998. I know what to look. That image when I saw that at Empire Tower Park screen 6 April 2012, I looped the image in my mind for 5 or so months. Can you do that? Hold on to a few single frames, as I knew this would show up on bluray.
Image


Direct transfer Laserdisc to DVD-RW so I can capture image. (whites are whiter on TITANIC LD) :thumbup:
Image

Bluray transfer to DVD-RW so I can capture the image (proof bluray does look like seasick green) :thumbdown:
Image

THX LD I know what LD means! Lovely Disc! :) :D :angel:
Image

Bluray in seasick green HD I what HD mean! Horrible Disc1080p! :lol:
Image


The defence finds bluray TITANIC guilty of computer seasick tweaking colour :thumbdown: and that THX Laserdisc TITANIC is the winner. :thumbup:

I rest my case.
Author:  sdraper [ 18 Jun 2013, 18:19 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
Cameron like many today seems to have a teal fixation. Many films are re-timed and given a teal look, for example the recent new transfer of THE TERMINATOR has a great and detailed scan but is retimed to be teal cast.
Author:  graz138 [ 18 Jun 2013, 21:39 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
Wow. Nice side by side comparison!
Author:  alien [ 19 Jun 2013, 06:32 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
laserbite34 wrote:
alien wrote:
laserbite34 wrote:
Playing "TITANIC" (1997) Dolby Digital AC-3, THX sound system, presently on disc 2 side 3, it looks better than the bluray and sounds better in my listening opinion having listened to the film, close to over 100 times since its release in early Jan 98.

Looks better then the Blu-Ray? How so? I have never seen anyone claim a LD version of a movie looks better then the Blu-Ray version.


The defence finds bluray TITANIC guilty of computer seasick tweaking colour :thumbdown: and that THX Laserdisc TITANIC is the winner. :thumbup:

I rest my case.

Wow that green tint looks horribly digital and out of place, looks terrible. The Blu might destroy the LD (and DVD) as far as detail and sharpness goes, but the colour timing looks far more natural and accurate on LD/DVD. You are right Laserbite.

Also what makes the sound better on the LD compared to the Blu?
Author:  alien [ 19 Jun 2013, 06:36 ]
Post subject:  Re: AC-3 Dolby Digital vs 2.0 PCM
sdraper wrote:
Cameron like many today seems to have a teal fixation. Many films are re-timed and given a teal look, for example the recent new transfer of THE TERMINATOR has a great and detailed scan but is retimed to be teal cast.

Actually The Terminator on the 2012 Blu-Ray is closer to how the film looked originally pre the 2001 special edition DVD which was given a wrong pink push. The Image Entertainment DVD version from the late 90's looks closer to the new remastered Blu-Ray with a focus on green. SO bascially all the the DVD releases post 2001 including the old 2006 Blu-Ray which came from the 2001 master are wrong and while the 2012 Blu-Ray is not entirely accruate, its much closer then any of the DVDs ever were. .
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