DTS 5.1 vs dolby digital 5.1 vs 24/192 master in pro tools (1 Viewer)

[Mark Lucas]

It seems like dialnorm has no business being attached to movies. All this back and forth digital attenuation is making me sick.

 

[JeremyErwin]

As long as we're quoting sacred texts, may I present this fragment from Codex A52


In other words, it tells the receiver to turn the volume knob. It does not shift the PCM buffer, or multiply the contents of that buffer by a constant.

 

[DaViD Boulet]

Jeremy,

thanks for posting.

What in the world is that talking about? There is no connection between the value of the "volume knob" as selected by the listener and the Dolby Digital Dialog Normalization attenuation process as far as I know. I've certainly never heard of any decoder that gives volume-level-feedback information from the user's preamp-stage-volume adjustment to the Dolby Digital decoder chip. Bizarre to even think about it! I mean...Dialog Normalization even happens inside a stand-alone DVD player with 5.1 output which has no way of knowing anything about the preamp-stage volume adjustment on your receiver.

I'm not sure what that text is talking about...perhaps it's suggesting what "would" be necessary in order to have the system work perfectly in an ideal world when you're trying to level match between Dolby Digital and *non*-Dolby Digital sources?

As long as all of your sources are passing through the *same* Dolby digital decoding chip, then the volume of the "knob" on your preamp makes no difference because the decoding chip is handling all the audio and can properly make sure that each soundtrack is adjusted since it has its own internal reference point.

The only time a decoding system would "need to know" the literal analog pre-amp volume setting would be if your Dolby Digital decoder was charaged with the task of matching level to non-Dolby Digital sources...like your analog stereo from your VCR and your TV tuner etc.

Obviously, that's not part of the Dolby Digital Dialog Normalization process...

 

[JeremyErwin]

The dolby encoder does have an option for Dynamic Compression (Film Light, Film Standard, Music Light, Music Standard, None) (see this for additional information). Perhaps this setting is responsible for the perceived differences between a good dolby digital track and a poor one.

My receiver is, unfortunately, an entry level one, and does not tell me what levels of dialnorm have been applied, so I have no means of correlating this with perceived sound quality. Perhaps someone on this thread does have the necessary equipment?

I think we're all familiar with the argument that audio equipment cannot really be compared unless it is level matched. If it is not, the louder source tends to garner the most accolades. So, on a very simplistic level, dts tracks should sound more detailed, simply because they are louder-- soft details become more apparent, and so on. Of course, if ones amps and speakers are not up to the task of playing 109/119 db sounds, well...

 

[DaViD Boulet]

However most of us take care to level-match as best we can when comparing DTS to DD etc. I know I always turn the volume up/down accordingly so that they sound "the same loudness" before I start to get picky and notice stuff like "more natural" or "more cohesive surrounds" etc.

 

[Marti D.]

Marti D. replies:
Here is a link to some of my work:
http://imdb.com/name/nm0401937/?fr=c...u;fc= 1;ft=21

Here is my place:
http://www.thedubstage.com/facility.php

As for the equipment, guess what, I have the same stuff. You get limited track count at192! while you can do it, the movies I do I get well OVER 100 tracks (The Excorcism of Emily Rose was 185 tracks of sound effects and Sound design. Add Dialog, Group and Music you have about 300 tracks!).

You can't do that at 192K.
Both the Dolby Encoder and DTS change the original sound. The DTS box is known to be about 1 1/2 db louder output than the Dolby box. That may be what many of you are hearing. In Hollywood Dolby sends a technician to Print Master the movie to his digital encoder. DTS doesn't. What DTS gets is a Digital 5.1 file of the mix, but no one ever sits in on the mix or in my experience asks any questions about the mix. Dolby is very good about making sure what you hear on "the dub stage" is on the Print Master.
What all of you hear on DVD's is what a DVD encoding person (I won't say engineer because the vast majority are not engineers) work on getting the mix onto a DVD. Even DVD's are a comprimise vs. the original mix.

 

[DaViD Boulet]

Marti D.,

thanks for contributing!



Without a doubt!