Film-Tech Forum ARCHIVE: Blu-Ray sound formats

This is topic Blu-Ray sound formats in forum The Afterlife at Film-Tech Forum ARCHIVE.

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Posted by Claude S. Ayakawa (Member # 1401) on 12-01-2009, 02:53 PM:

When Blu-Ray emerged the winner after battling it out with HD-DVD, I had noticed the use of sound formats between Dolby TruHD and DTS HD Master AudIo Just about even between the studios releasing movies on BD. Since than, Disney switched to DTS and Universal selected the sound format too when they began releasing Blu-Rays. It now appear the two of the strongest supporter of the Dolby sound format, Sony and Paramount are also moving over to DTS. That leaves only Warner Brothers in the Dolby camp. It is interesting to see what Warners will do about DTS after they had released WATCHMAN and TERMINATOR SALVATION in the format on Blu-Ray and announced THE NEVERENDING STORY and THE CLASH OF THE TITANS in DTS in February.

I was partial to Dolby when they were slugging it out with DTS and SDDS during the theatrical sound competition but preferred DTS sound on laserdiscs and DVD. Although I cannot hear the difference between Dolby and DTS sound on Blu Ray because I do not have the proper sound equipment to play back Dolby TrueHD and DTS HD Master Audio, I still prefer DTS.

-Claude

Posted by Demetris Thoupis (Member # 833) on 12-01-2009, 03:04 PM:

In reallity still DTS uses less compression than Dolby in any format. The difference when making a direct comparison is very clear, i.e switching from Dolby HD to DTS HD format the information in the surrounds is boosted and also a better Low Frequency channel. I have heard that DTS is greatly considered for audio playback in the Digital Cinema realm as well but I am not sure whether these are rumours.
Demetris

Posted by Chris Slycord (Member # 4239) on 12-01-2009, 03:10 PM:

I'm confused by the above post.

Are you telling me that one lossless format sounds better than another?

Posted by Joe Redifer (Member # 3) on 12-01-2009, 03:52 PM:

Well, it can appear that way, yes. Dolby TrueHD often sounds much quieter. Remember that Dolby likes to stick in bullshit like midnight modes and other dynamic range limiters into their code to trigger in compatible receivers. All of this shit is difficult to turn off completely and many people don't even know about it. I have noticed on my receiver that I must turn the volume up much higher when playing a Dolby TrueHD mix than with a DTSHDMA mix.

That said, Dolby TrueHD can sound incredible, every bit as good as DTSHDMA. But unfortunately the only Dolby True HD mix that has blown me away so far has been on The Nightmare Before Christmas. Maybe they forgot to include the dynamic range limiters in the code?

The problem is not the codecs themselves, the problem is whoever uses them. If you took the same source and encoded it properly in Dolby TrueHD and DTSHDMA, there would probably be no difference whatsoever. I just don't think the studios use TrueHD properly. A lot of people say that DTS sounds 10 times better than Dolby Digital on DVD. It doesn't. It's just that the source used in the DTS mixes is much louder. I have encoded the same source audio into Dolby Digital and DTS for DVD before, both at the full bitrates they were capable of. There is very little audible difference between the two, and the surrounds and sub certainly weren't more aggressive in one.

On Disney DVDs like Pirates of the Caribbean, the Dolby Digital mix usually sounds better and much less harsh than the DTS mix. It is clear that two different audio masters were used.

Posted by Bobby Henderson (Member # 840) on 12-01-2009, 06:17 PM:

"Dialog Normalization" is one of those sound-altering features often used in Dolby Digital and Dolby TrueHD audio tracks. My understanding is Dialog Normalization can be disabled in the audio track if the people authoring the title choose to do so. End users are left jumping through hoops turning of/off various Dolby Digital features.

To date, I have used the "night mode" with Dolby Digital audio only a couple of times. And that was only because a female friend of mine didn't like the startling dynamics found in the "standard" and "maximum" modes.

Dolby TrueHD and DTS HD Master Audio both have tremendous potential, much of which is going largely unused. Both formats can deliver 5.1 or 7.1 audio in 24-bit 96kHz resolution as well as 2.0 stereo in 24-bit 192kHz resolution. Some concert discs and other unique titles, such as Baraka, have taken advantage.

I did notice the upcoming Blu-ray release of Sex Lies & Videotape features a 24-bit 96kHz Dolby TrueHD 5.1 audio track. Arguably overkill there since that movie is overwhelmingly dialog driven.

The best that most movies can seem to do is encode 24-bit 48kHz audio in Dolby TrueHD or DTS-HD Master Audio at bit rates ranging from 3600kb/s to 4600kb/s. Quite a few titles out there are using 16-bit masters and significantly lower bit rates, some of which dip down to levels nearly as low as the 1509kb/s rate used by the "full" version of lossy DTS.

In short, audio masters vary in quality greatly just like film elements and video masters. Blu-ray is just doing a better job of drawing our attention to those differences.

Regarding movie studio preferences between Dolby TrueHD and DTS-HD Master Audio, a few variables are involved. Hollywood politics could be at work. Maybe the studios using DTS-HD are marketing to what they think Blu-ray customers want. It certainly seems like most home theater fans are drawn more to DTS. The company seems to have an image of upholding higher audio standards while Dolby is more mainstream. What is Dolby and DTS charging studios in licensing fees for their surround formats? Is DTS-HD Master Audio less expensive for studios to use?

I never expected DTS-HD Master Audio to reach a level of dominance on Blu-ray like what is taking place currently.

It wasn't much of a surprise for studios like Universal, MGM or even Lionsgate to use DTS on most or all of their Blu-ray releases. I was a little more surprised to see Fox use DTS-HD exclusively; the studio has used DTS on all but perhaps a couple of its Blu-ray releases. I didn't expect Disney to shift to using DTS-HD. The similar move by Sony has been even more surprising. Paramount/Dreamworks and Warner Bros. are still very much in the Dolby TrueHD camp, although it is interesting to see them dabble with DTS-HD on certain releases.

Posted by Joe Redifer (Member # 3) on 12-01-2009, 07:04 PM:

When encoding Dolby Digital, one must set the dialog normalization to -31db. That disables all of that nonsense. Most people seem to either leave it at default or set it at 00db. Bad move.

I noticed that with the PS3 Phat that Dolby TrueHD had a very low-sounding center channel when converted to PCM. The PS3 Slim bitstreams and now the dialog is more clear as a result. The Dolby True HD decoder for the PS3 must be a bit faulty. I still have to turn Dolby TrueHD mixes up louder than DTSHDMA mixes, but not as much as before. With PCM I couldn't turn some movies like The Matrix up loud enough.

Posted by Bobby Henderson (Member # 840) on 12-01-2009, 07:54 PM:

For LPCM output, did you have the BD/DVD Dynamic Range Control option set to "off"? I thought this PS3 setting would disable some of the dialnorm nonsense with DD tracks.

In going through some of the PS3 audio settings, the system seems to have been upgraded to allowing simultaneous audio output from both HDMI and optical outputs. That's via a new "audio multi-output" option I don't remember ever seeing before.

Posted by Joe Redifer (Member # 3) on 12-01-2009, 08:10 PM:

I'm sure I did have it off. What are the other settings?

As for the Audio Multi-out, it is useless. The HDMI defaults to stereo.

Posted by Bobby Henderson (Member # 840) on 12-01-2009, 08:49 PM:

Too bad about the HDMI multi-out thing. At least I can hear the movie over my HDTV's speakers and my home theater speakers if I want to do something silly like that.

I'm not sure if there's any other settings the PS3 can apply to audio. I looked through music settings and audio settings. Oh well. All the more reason to not mind such a huge shift to DTS-HD on the Blu-ray front.