Video Essentials and Avia speaker level test tones have a -4 Dialnorm? (1 Viewer)

[Mario_C]

While reading the updated (Aug 2001) article on Dialnorm from Secrets of Home Theater and High Fidelity, I came across the following:
quote: A common criticism is that Dialogue Normalization "normally" reduces the level of the soundtrack by about 4 dB.* Reduces it as compared to what? You have to compare it to something else first, and then the question becomes:* is the Dolby Digital soundtrack 4 dB too low, or is the other material 4 dB too high?** Follow me on this one.
A lot of home theater enthusiasts are concerned with what is called "reference level playback". *In a nutshell, you use test-tones (as may be found on such DVDs as AVIA) to set the volume to the same standard levels used in cinemas (a.k.a.: loud!).* The reason to do this is to hear the soundtrack at the level the movie makers intended.* A concern naturally arises that if volume is being altered by Dialnorm, the sound engineer's vision is compromised.* Reference level playback is in practice very very loud in the relatively small acoustic spaces of home, and we must caution you against it at this point.* Not only do most find it uncomfortably loud, but as we noted in our article explaining the LFE channel, it can quickly bring a subwoofer to its knees.* But for the record, let's press on.
The default power-on setting for Dialnorm on Dolby's professional AC-3 encoder, the DP569, is -27 because as we noted, that value is a perfect fit for movie soundtracks.* True, this value calls for your decoder to attenuate its output by 4 dB.* Fact is, the two most common reference DVDs, Video Essentials and AVIA, were encoded with the same -27 Dialnorm value, so their test noises are also being attenuated by 4 dB, making them a perfect reference for Dolby Digital movies.* If you've set-up a system with either of these tools, then any movie you play will not be "reduced" by 4 dB as compared to the reference.
DTS soundtracks, unlike Dolby Digital, are not attenuated by 4 dB by your decoder.* This means that if you've set up your system using AVIA or Video Essentials, the DTS soundtrack is actually going to play 4 dB too high.* Yes, that's right.* You read it here:* On a system calibrated for reference level playback with Video Essentials or AVIA, DTS soundtracks play 4 dB too loud.* Conversely (and to be fair), if you set up a system using DTS test noise, the Dolby Digital soundtrack will be 4 dB too low.* Yet what is important here, and what I really want you to take away from this, is that regardless of what actual level you watch a movie at, relative to one another, there exists this 4 dB difference between DTS and Dolby Digital movie soundtracks played over consumer equipment.* If at any time you are comparing soundtracks, you must turn your volume down when listening to the DTS track and/or raise it when listening to the Dolby Digital track (as the case may be) in order to hear the same level from both.
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I just thought people who use Avia or Video Essentials to calibrate their speakers should know about this. I use "The Ultimate DVD Platinum" It has speaker calibration test tones in PCM stereo, Dolby stereo, Dolby Surround, Dolby Digital 5.1, and DTS 5.1. I have compared these test tones and there are all at the same levels.
I do want to pick up a copy of Avia for monitor calbration or the new Digital Video Essentials. There taking pre-orders at Amazon.com
Here is the link to the article Link Removed
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Link Removed
[Edited last by Mario_C on September 10, 2001 at 04:48 PM]

 

[Guy Kuo]

Just to clarify, the dial norm for the AVIA test tones is the industry standard -27 dB as indicated in the referred article, not the -4 in this topic header.
Every time dial norm is brought up, a huge amount of confusion is raised. My answer to this is to read the Brian Florian article several times until you understand what dial norm does. It is metadata for amplifier gain and does not alter the encoding bit accuracy.
The take home messages are.
1. You don't need to nor should you disable dial norm on your receiver or processor.
2. DTS tracks are done with essentially in such a manner that they play back 4 dB louder than DD tracks so if you want to compare DTS and DD tracks fairly you must compensate with your volume control by 4 dB to make them play back at the same loudness.

 

[Mario_C]

>>>Just to clarify, the dial norm for the AVIA test tones is the industry standard -27 dB as indicated in the referred article, not the -4 in this topic header.>2. DTS tracks are done with essentially in such a manner that they play back 4 dB louder than DD tracks so if you want to compare DTS and DD tracks fairly you must compensate with your volume control by 4 dB to make them play back at the same loudness.