TrueHD vs. TrueHD - Is All TrueHD Created Equal?

[Hunter]

Originally Posted by Marcusarilius

Question: Does the decoding process in any way or to any degree, lessen the quality of the sound?

No

[Ascended_Saiyan]

Originally Posted by cajmoyper

Are you kidding me? I've heard both I Am Legend and Dogma. Dogma doesn't hold a candle to the IAL track. Bitrates aren't the endall factor in being able to tell what's best. If it weren't for that bitrate counter at the top of your screen, you wouldn't even be able to tell TrueHD from DD.

You can't qualify anything so subjective as sound without some science. The bitrates are scientific. You can't hide from them. In other words, stop talking about my bitrate counter. It's the only thing keeping this subject from being totally subjective.

Originally Posted by Ascended_Saiyan

It's not about the one example I gave. Clearly, I said "all" or any titles from Sony that match with Warner titles audio wise (16bit vs. 16bit).

Using PSP... otherwise I would spell everything out.

Gattaca is Sony 16bit.

Originally Posted by Slec

Ascended... I've dug through some of the stuff Sir Terrence has posted on in his Insider thread (may be a good place for your question as well). here's my bastardization of some possibilities

Not all sound effects are recorded in 48/24. So if some is 48/24 and others are 48/16, it may be part of the issue and they will vary from movie to movie.

This one backs up what Wicky was saying and why its a bit difficult to compare tracks and peaks: Link
my emphasis is bolded.

Put those two together and it could be a reason. I'm not discounted the HD DVD theory... that's why it may be a better question for an insider.

Originally Posted by RBFilms

I do not know the specs on the soundtracks...but it could be a 24 bit verses 16 bit quality difference you are hearing. Don't tell the MS Boys this if it is the case....they will send a team of deprogrammers in the middle of the night to convince you that there is no difference between 16 bit and 24 bit...

Perhaps ... albeit I am not sure ... it could just be a filtering and engineering issue. Not all mixes are created equal and decimation / brick wall filters are used in many electronic instruments. Sound libraries are also of limited quality.

All of this can create a sense of reduced fidelity by comparison. Just listen to how lousy many CD Recordings sound these days. There are a multitude of reasons why they do not sound great. It is simply not possible to compare two different soundtracks and identify any one thing that makes one worse than the other. Some producers and engineers are more concerned about quality than others.

In the end, you can see / hear the difference when someone is paying attention throughout the process.

Thank you fo the responses! I'm back on a keyboard on my PS3. I can now explain in great depth what I see (I will add more information from more titles). I was hoping this would make people pull out their Sony and Warner BDs and start testing what I have been suggesting.

Now, I will just give examples to compare to my OP (will add the rest when I find the paper with my observed numbers)...

Sony - Gattaca (16-bit) averages around 2.4 to 2.6Mbps (on NO music and low dialog scenes)...Peaks at 4Mbps
Warner - Letters From Iwo Jima (16-bit) averages around 1.4Mbps (a war movie...you KNOW that has a lot of sound effects)...Peaks at 3Mbps
Warner - Invasion (16-bit) averages around 1.6Mbps...Peaks 3.1Mbps
Warner - The Brave One (16-bit) averages around 1.4Mbps...Peaks 2.8Mbps
Warner - The Reaping (16-bit) averages around 1.5Mbps...Peaks 3.2Mbps
Sony - Legend of Zorro (16-bit) averages around 3,2Mbps...Peaks 5.2Mbps
Sony - Spider-Man (16-bit) averages around 1.5Mbps...Peaks 3.2Mbps

I will add the peak rates as well.

EDIT: Averages and Peaks have been added. The only thing other than one of the two options I offered in my OP is that the reviews have the wrong information on the audio source.

[Slec]

Originally Posted by Slec

Ascended... I've dug through some of the stuff Sir Terrence has posted on in his Insider thread (may be a good place for your question as well). here's my bastardization of some possibilities

Not all sound effects are recorded in 48/24. So if some is 48/24 and others are 48/16, it may be part of the issue and they will vary from movie to movie.

This one backs up what Wicky was saying and why its a bit difficult to compare tracks and peaks: Link
my emphasis is bolded.

Put those two together and it could be a reason. I'm not discounted the HD DVD theory... that's why it may be a better question for an insider.

On the sound effects recording point I see I left out my actual point... Even if the track is a 48/24 track, the sound effects might have been recorded in 16 bit for that particular film...thus causing a lower than expected output.

[Hunter]

Originally Posted by Ascended_Saiyan

Sony - Spider-Man (16-bit) averages around

Spider-Man was upconverted by Sony to 24-bit

[Ascended_Saiyan]

Originally Posted by Hunter

Spider-Man was upconverted by Sony to 24-bit

Can you list your source? The bitrates do not support your your theory.

[Slec]

Originally Posted by Ascended_Saiyan

Can you list your source? The bitrates do not support your your theory.

High def digest

Audio specs for the three 'Spider-Man' flicks in this Blu-ray box set vary somewhat. Although all three films receive Dolby TrueHD options, 'Spider-Man 3' is the only one to also include an uncompressed PCM track. Additionally, technical information provided to us by Sony reveals that although the TrueHD tracks for all three films are encoded at 48kHz/24-bit, the actual master sources for 'Spider-Man 2' and 'Spider-Man 3' are 48kHz/24-bit, while the original 'Spider-Man' is and 48kHz/16-bit. (In other words, the first film is an upconvert.)

[Ascended_Saiyan]

Interesting. Check out the bitrates I added to post #22 earlier.

[bluseminole]

Originally Posted by cajmoyper

If it weren't for that bitrate counter at the top of your screen, you wouldn't even be able to tell TrueHD from DD.

Okay, this may be off topic, but I have a huge problem with that. Why do we even bother with lossless audio if this is the attitude on an entusiast forum? And to accuse another member of not being capable of hearing said improvement.....

I think you should check out this thread:

When enthusiast sites fail to show any enthusiasm

What a fantastic way to impress the importance of HD audio on the general public: "Turn your bitrate meter off and you won't hear a difference!"

No wonder high-res audio never took off...as long as they don't know MP3s are only 128kbps, they'll never HEAR the difference.