Understanding Dialog Normalization

[terminal33]

Originally Posted by shadow72

I own, and checked, Braveheart and it is -4db which is the typical TrueHD dialnorm.

Is there a dialnorm for the new Star Trek?

[Big Daddy]

Originally Posted by terminal33

Is there a dialnorm for the new Star Trek?

It is -4dB. Please refer to Dialog Normalization Table in Post #2.

[terminal33]

Originally Posted by Big Daddy

It is -4dB. Please refer to Dialog Normalization Table in Post #2.

Wow! I'm watching it right now at -12, which is what I usually do. I can't imagine turning it up 4 notches on the master volume. The bass at -12 is already awesome and leads me to believe that turning up the volume would bottom out my sub (Ultra 13).

For Transformers 2 I listened at -7, which was fine. But the bass at -12 for Star Trek is way more powerful than TF2 at -12. Why does -12 for Star Trek seem louder and have a more powerful LFE?

By the way, so far I know that the cannon scene in the school yard from The Incredible Hulk bottoms out my sub at -12. Whenever that scene comes on, I have to lower the volume when the cannon is fired. It seems that turning up the volume on Star Trek by 4 notches would certainly do that same.

Is there something wrong in my thinking?

[Big Daddy]

Originally Posted by terminal33

Wow! I'm watching it right now at -12, which is what I usually do. I can't imagine turning it up 4 notches on the master volume. The bass at -12 is already awesome and leads me to believe that turning up the volume would bottom out my sub (Ultra 13).

For Transformers 2 I listened at -7, which was fine. But the bass at -12 for Star Trek is way more powerful than TF2 at -12. Why does -12 for Star Trek seem louder and have a more powerful LFE?

By the way, so far I know that the cannon scene in the school yard from The Incredible Hulk bottoms out my sub at -12. Whenever that scene comes on, I have to lower the volume when the cannon is fired. It seems that turning up the volume on Star Trek by 4 notches would certainly do that same.

Is there something wrong in my thinking?

There is no right and wrong as far as volume is concerned. It depends on your taste, hearing, and equipment. It is wise not to overdrive the speakers and subwoofers. As long as they are calibrated properly and you set your volume to a reasonable level, you will be ok.

[BIslander]

re: Transformers 2, which version was used for the -4dB listing in the chart? I've read elsewhere that the Walmart version (the one with the Imax scenes) has lower than expected volume. Perhaps the Walmart version has a -27 dialnorm value while the other version uses -31.

[Darth Olsson]

Been searching high and low for an answer to my this, ... but to no avail. And I can't find a good place to place this post - so sorry for butting in on this audio discussion.

At issue is this: My Slumdog Millionaire BD does not work on my PS3.

I say "won't work" as opposed to "won't play" because the disc does not even "show up" in the PS3 menu like every single other BD/DVD/CD I've ever put in. Normally on a PS3 you would get a little blue disc looking icon for when a BD is loaded. In the same menu you would also see the "BD Data Utility" folder. When I load in my "Slumdog" BD - the disc icon never appears.

After having doodled around with it for a while I went ahead and upgraded the firmware on the PS3 to the latest - this made absolutely no difference whatsoever. Final note: This is the only disc ever encountered that has not played flawlessly. I'm stumped!

HELP HJÄLP HILFE !!
--------------------
Pioneer Kuro (PDP-5010FD)
Sony PS3
--------------------

[Hammie]

Originally Posted by Darth Olsson

Been searching high and low for an answer to my this, ... but to no avail. And I can't find a good place to place this post - so sorry for butting in on this audio discussion.

At issue is this: My Slumdog Millionaire BD does not work on my PS3.

I say "won't work" as opposed to "won't play" because the disc does not even "show up" in the PS3 menu like every single other BD/DVD/CD I've ever put in. Normally on a PS3 you would get a little blue disc looking icon for when a BD is loaded. In the same menu you would also see the "BD Data Utility" folder. When I load in my "Slumdog" BD - the disc icon never appears.

After having doodled around with it for a while I went ahead and upgraded the firmware on the PS3 to the latest - this made absolutely no difference whatsoever. Final note: This is the only disc ever encountered that has not played flawlessly. I'm stumped!

HELP HJÄLP HILFE !!
--------------------
Pioneer Kuro (PDP-5010FD)
Sony PS3
--------------------

You might get more traffic in the Blu-Ray Players and Recorders Thread.

[KC-Technerd]

Originally Posted by Big Daddy

[*]The default settings for Dolby encoders is -27dBFS.
[*]The default dialog setting for DTS is -31dBFS.
[*]DTS soundtracks, unlike Dolby Digital, are not attenuated by 4 dB by the receiver/decoder and as a result DTS movies play 4dB louder than Dolby Digital movies.
[*]It should be noted that most THX-certified receivers and processors attenuate DTS movies by 4dB.

I'm confused as to how all this plays into how my Pioneer SC-77 is apparently processing everything. It apparently sets the volume relative to the -27 dB metadata level (based on the DIAL NORM numbers it displays), and does no further attenuation. This results in a volume level that is 4 dB louder (for both Dolby and DTS) than if I set my Oppo BDP-103 to do the bitstream processing (which I'm assuming is setting volume relative to the -31 dB metadata level). I'm measuring no output difference between Dolby and DTS in any case. The Pioneer SC-77 is a THX-certified AVR. From what I'm reading above, it sounds like that if anything the SC-77 should be attenuating DTS 4dB in which case it would be 4dB quieter than when the Oppo is doing the bitstream conversion.

Anyone have any thoughts on how this all fits together?

[BIslander]

Perhaps you should contact Pioneer support.

[RXP]

What a fantastic post - I was interested in all this after trialing TIDAL with Dolby Atmos music - it uses an offset value for music. So know we finally have a reference volume for music.

Does anyone know if Dolby Atmos tracks in movies make use of Dial Norm on 4k UHDs?

Edit: A good (critical) article on it here

Finally, we have a bit of a reprieve from on high when it comes to Dolby Atmos/TrueHD tracks on 4K Ultra HD Blu-ray (and maybe Blu-ray; I haven’t looked at a Blu-ray Disc in years). All the ones I’ve looked at so far have DialNorm turned off (DialNorm -31dB or 0 off set).

[RXP]

So I thought I'd start measuring my movies to see what their average loudness is. What a rabit hole that turned out to be for a couple of days. Lots of industry articles from mixing engineers which has been really useful.

My primary interest is ensuring I can listen at 85db average, when I want to and not risk hearing damage.

We've all been told that calibrate your kit and hit 0 on the volume and it'll be reference. In my personal experience that just wasn't the case - some movies were just way too loud at reference. I believe this is where people thinking reference volume being too loud comes from. I thought dialnorm would rescue me, but the article I posted above clearly shows there's no science behind it. In principle it can work great - Netflix is an example of that.

There's a fantastic tool ffmpeg-normalize. It uses the ITU spec for "Integrated Loudness", basically a better psycho-acoustic measure of loudness for the digital domain to measure files average loudness.

Below are 3 movies (higher value is louder)

• Spectre (2015) -13.27 LUFS
• Godzilla (2019) -15.29 LUFS
• Skyfall (2012) - 14.56 LUFS

-21 LUFS = 85dbC
- 27 LUFS = 79dbC

At 0 on your AVR, without any offset, these movies go well beyond 85dbC. So if you hit up 0 on your AVR Spectre will hit an average of 92.73db. Remember this is all in the digital domain so there's no speculation about rooms or reflections etc. This is simply how loud it is.

Even a typical offset of 4db that you apply to DTS won't solve it. It'll actually have to be an 8db offset to hit 85db average.

This also rings true to the Audioholics recent YouTube video* on loudness in movies. Frozen 2 achieved 89dbA on a calibrated dosimeter.

I found a sensible article from an industry insider on recommendations for loudness in commercial cinemas which i'll be adopting at home.

If the Program Level is at or below -27 LUFS: just play it as it is. With low levels, the movie is probably intended as a "soft movie".

If the Program Level is above -27 LUFS, check if the cinema has set the "loud movie playback" option. If not, attenuate the soundtrack during playback to -27 LUFS. If yes, check if the Program Level is above the absolute limit of -21 LUFS. In that case, attenuate to -21 LUFS.

In my case - my system is capable of 105db peaks so for big budget action movies I'll hit -21 LUFS (85dbA) and for regular movies I'll hit -217which is 79dbA

I didn't realize there was a loudness war going on in movies. Insiders are claiming that dynamic range is much more compressed than 10 years ago. Because crowds have been complaining that movies are too loud the cinemas turn their volume down.

Because they turn their volume down, mixers know they need to achieve a higher level for dialogue in order to be loud enough - which compresses dynamic range. In the article a movie mastered for TV according to the R128 spec had more dynamic range than the cinema version!

As a home cinema nerd I was also amazed at just how varied the mixing conditions are. From an industry survey there's very little standards. Some are mixing at 79, some at 83, some at 85. Some wear ear plugs.

In summary if you like to listen loud but want to have peace of mind that you won't case hearing damage - ffmpeg-normalize can compute the LUFS of the movie which you can then offset in your AVR menu. That will also keep things like Dynamic EQ/Volume which rely on a known reference volume working ideally.

*

When is it Too Loud? Safe Headphone & Movie Listening - YouTube

[PeterTHX]

Saw Spectre with the family in an AMC theater.

It was deafening. I like movies loud and all when they need to be but it made watching the film very unpleasant. The fam ended up getting free passes from management.

[RXP]

I don't mind the volume per se at home it's easy to turn down - but things like Dynamic EQ and Dynamic Volume from Audysey rely on a known reference volume. I was questioning the reference being too loud. But if that's how you remember at AMC - maybe not.

But at least with ffmpeg-normalize I can scan big block busters and adjust accordingly. Some, like Disney I think will need increasing! I'll process more and report back.

The two articles I linked to in the post have some sensible suggestions.
Part 1 and Part 2.

Part 2 was 4 years later and nothing had really changed.

As the author writes

The current dynamics in the cinema are now smaller than that with a R128 television broadcast.

I only go to premium ones like IMAX. I believe their mastering process preserves more because it is damn loud and quiet passages are quiet. But I did see Ad Astra in a cinema in Swtizerland. What I noticed was the Dolby Spheres demo clip was pretty impressive before the presentation, but the actual presentation was very quiet. The articles above are from European industry insiders.

All this makes me really look forward to the IMAX Enhanced audio tracks. Not because of some fancy processing - but only because they are more likely to control for all this.

[PeterTHX]

Originally Posted by RXP

All this makes me really look forward to the IMAX Enhanced audio tracks. Not because of some fancy processing - but only because they are more likely to control for all this.

They're still subject to home video mastering. It's not the same as theatrical IMAX.

[RXP]

The good thing is I can analyse them when they're out anyway - I'm sure the BassEQ people at AVSforums will also be all over it.

Age of Ultron Blu-ray/DTS was reviewed on this site with complaints about low level, echoed on the thread. And the Atmos was even worse.

Age of Ultron DTS Track: -21.41 LUFS
Age of Ultron DTS-HD Track: -23.31
Age of Ultron Atmos track: -25.61 LUFS


The DTS track is ~84db avg, HD is ~82 and Atmos is 79db Avg. This is at 0 on your AVR. So no wonder they seemed light. The DTS track would need a 6db boost to get it to the levels in Kong 8db for DTSHD and 11db for Atmos! The Atmos track didn't have dialnorm. So this is playback level too.

This is also an explanation of why some of these movies hit so light on the LFE. If the level is low, and they're not being boosted via the input volume trim on your AVR, then any house curves/loudness compensation won't kick in. So we perceive less bass due Fletcher/Munson curves.

If however you trim to -21 LUFS/85db the loudness compensation can take care of it. Those with manual house curves can then just reset their house curve for their AVR at 0

[RXP]

So I figured out a way to apply an A weighting in Audacity to manually compute the levels. Graphic EQ and ACX plugins were used.

A weighting is a better indicator of how we hear and its used for hearing loss prevention. Bass in movies is really throwing off the LUFS numbers for hearing safety analysis.

When you analyse A weighted Spectre is actually only 82dbA. Well below the threshold of hearing loss.

In summary: ffmpeg-normalize is very useful to fix these low mixes we seem to get now days. Find a mix volume you like. Personally for me it's Kong. Boost any big block buster movie to that. Then you'll get rid of the At-mouse. It makes little sense to do that with a quiet movie. Just leave those as is. DialNorm simply isn't going to get you there.

You don't need to worry about hearing loss from listening at reference volume. Just ensure you are actually running at reference and you can only do that with a calibrated SPL meter (e.g. UMIK with calibration file loaded). A Radioshack or phone app won't do it. In my case my Audyssey mic set my F/C/R levels between 3 and 4db too high

[CreasyBear]

I've had a few instances in the last several years where theaters were too loud. I saw BvS at an IMAX and I thought I was going to have hearing loss after the opening scene in Metropolis. Thankfully, they were able to turn it down. That's the first time I've ever done that. I saw Rise of Skywalker this past December at a Marquee Cinemas MXC theater and it was just deafening and I had to leave and get a refund because they refused to turn it down, despite the fact that there were only a handful of people in the theater. I've never been to an Atmos theater, but based on a couple of experiences at IMAX, I'm just not sure how enjoyable it would be given how loud the films play.

[ton4eff]

I did some experiments with my Onkyo TX-NR696 receiver. Dolby Digital file encoded with a flag at -27dBFS, plays as it is - no dialog normalization applied. If it is flagged at -31dBFS, Onkyo adds +4db dialog normalization. Yes, it does exactly what it says on the display: it increases the volume by +4db. For DTS file encoded at -31dBFS, it also applies +4db. So a Dolby Digital file flagged at -27dBFS and a DTS file flagged at -31dBFS sound equally loud. So I'm assuming that Onkyo applies dialog normalization to anything different from -27dBFS. I can send the test files to anybody who's interested.

[PeterTHX]

Originally Posted by 49218

Well, apparently I was wrong.

My test files in TrueHD did not contain an AC3 core, but metadata for a downmix presentation with a secondary dialnorm value.

There is no such thing as an AC-3 "core". There is a hidden DD companion track which is completely discrete from the TrueHD. The TrueHD has metadata to tell non-compatible decoders to use the AC-3 track as the default. It is encoded at the same time as the TrueHD track, but the software has to be set to do this. It is DTS-HD MA that has a core lossy track, with the lossless information to re-add the missing data in the decoder (and why it's a lot more CPU intensive - the decoder must "rebuild" the lossless PCM original). It's also why a typical DTS-MA track uses a lot more data than a TrueHD track with the exact same info. The TrueHD track can go all the way to zero where the DTS-MA track will always be 1536 or 768kbps minimum.

Dolby is 4 dB louder than DTS, thus the AVR is only applying the dialnorm value of the lossless data, which is -31 in both.

Dolby is 4dB lower than most DTS tracks.

[PeterTHX]

Originally Posted by 49218

Not on AVRs following THX specs.

When both Dolby and DTS are flagged -31, Dolby will play 4 dB higher.

I've had THX receivers. They do not.