DD5.1 Vs Atmos DD5.1+ and Atmos TrueHD

[ThatGuyInLa]

You might be surprised...

I have really nice home audio gear. I won't go in to detail but it's GOOD stuff. I've also taken great care of my ears over the years. I never listen to amplified concert music without ear protection and I don't blow my ears out in my car. Which also has an insane audio system in it.

Despite all of this, anyone over 40-years old most likely, highly likely, cannot hear a sine wave over 14k to 16k. I'm 44. Of note, most all audio engineers mastering music, we all listen to, are over 45 and even 50 years old. And using a $600 pair of studio monitors.

I did an A/B of Bladerunner 2049 Blu-ray TrueHD Atmos versus Vudu DD5.1+ Atmos AND iTunes DD5.1 Now, this took some work. As all three required drastically different volume settings for my home theater. Each file was processed with different baselines. (it seems) After metering all three and ensuring I had the same db for all presentations, I gave it a critical listen. (the opening)

1. Yes. There is a marked difference in the presence and width with Atmos content. Undeniable. Even a casual audio listener should be able to hear the difference. HOO-RAH for Atmos!

2. I found no remarkable difference between TrueHD Atmos and DD5.1+ Atmos. None. Please keep in mind this is after making sure all sources were balanced! Blu-rays are LOUDER. This loudness has nothing to do with QUALITY. The discs simply ship louder. After balancing all three examples. I stand by my finding. LFE included.

3. DD5.1 (iTunes) sounded no different. Nothing about its presence, dynamic range, or clarity, seemed any different. Sans the expansiveness Atmos offers. It simply was not a fair comparison with regard to that. Again, points to Atmos. Still, I wanted to hear what I might be missing otherwise. The audible differences I did hear, as I've stated, I attribute solely to Atmos effects. Otherwise it was identical.

Now before you all get in a pissing match, do this yourself. Do not ASSUME. Do not allow yourself to fall in to others opinions (mine included) or the nature of psychoacoustics. That is, being told it should sound better, so it does. DO THE TESTS YOURSELF.

I was, for one, surprised. I was totally convinced I would hear vast differences in sound quality. My end results were that, yes, Atmos does sound much wider, deeper, and more involved, than non Atmos. However, TrueHd versus DD5.1+ Atmos, was indistinguishable. Again, once db levels were aligned. Louder, often will always, "sound better." You have to ensure levels are the same between tests.

So there's my report.

 

[BellsWhistles]

As far as I know, that is the core focus of the ATMOS technology (programmable sound staging). It was never about audio quality.

 

[ThatGuyInLa]

As far as I know, that is the core focus of the ATMOS technology (programmable sound staging). It was never about audio quality.

Correct. My surprise was comparing the "plain Jane" DD5.1. While lacking the gimmicks of Atmos, it still sounded as much as the disc based TrueHD. I've gone back again and given it a listen and still can't believe my ears. When I guess I should.

 

[HobeSoundDarryl]

An interesting followup test: get a helper and test again blind. When we know the sources (when we're our own helper), we may have biases to a favorite.

Maybe get a few sets of ears for a blind test, younger & older (ears).

Recall the HomePod tests when Apple controlled them and the ears knew which speaker was playing vs. when a followup test was done blind: https://finance.yahoo.com/news/head-head-apple-homepod-really-sound-best-160346138.html

I'm not saying that a blind test will yield a different outcome here. But I am saying that we're a pretty biased crowd. Post any thread of head-to-head anything and the Apple anything is going to be overwhelmingly crowned best. One might say "it's what we do."

Like you, I have very good equipment and pretty discerning ears. I strive to have no bias to any company, instead chasing better (or even best) wherever I can get it. I'd be very curious to know if this is re-done truly blind, if the outcome would be the same... or evolve much like it did with the HP blind test run by Pogue. He was quite surprised by the outcome, going in confident HP would win just as it did in Apple-hosted "tests." What a difference not knowing which was playing made!

If you have the gas for it... and the willingness to try... this would be an interesting thing to do and report back. If the outcome is the same, great (implying anything much more than DD5.1 ATMOS is overkill). And if the outcome is different, then the rationale for striving for better gets some support.

But either way, thanks for sharing. That's an interesting take on it's own.

 

[Audit13]

I found DD from the ATV to be inferior to DD+ and TrueHD. I also found DD+ and TrueHD to be much closer in quality to each other. My ATV would only send DD to my previous receiver so I replaced it and I'm very happy that my ATV sends a decoded DD+ signal to my current receiver.

Please post the gear you used. I'm always curious to hear about owner experiences with equipment.

Thanks.

 

[kiranmk2]

Very interesting. Agreed abot doing a double blind test to remove all unconscious bias, but a result that shows why TruHD Atmos will never come to streaming services.

 

[ThatGuyInLa]

Agree about bias, although my bias was TrueHD should sound that much better, heh.

 

[BODYBUILDERPAUL]

FASCINATING!!! I LOVE reviews like this. I've worked for 10 years in radio & studios before becoming a digital nomad
Again, my ears are in pretty lovely shape - super super super healthy natural bodybuilder/triathlete guy (NO CONCERTS ever, no alcohol ever, organic diet only, no long headphone use) and I've never been able to tell the difference between 320AAC / WAV / Apple Lossless /ALAC. I once did a comparison test (from some audio site) that compared the same pieces of music with codecs WAV, ALAC, 320mbps and 128mbps AND I preferred the 128mbps file in most cases - OOOPS DAMN - just goes to show more the importance of how the original film/soundtrack/album was produced/mastered! Always interesting to find a track on iTunes were it has appeared on many albums and listen to the difference between them all.

What should be interesting is that Apple have such high standards who it comes to their own compression etc of film, their iTunes films with ATMOS in DD+ should be of a very very high standard.

Thank you buddy for this. Please post more findings

 

[BODYBUILDERPAUL]

It kind of shows how incredible iTunes 4K Dolby Vision content with DD+ Atmos will be! Truly now makes me wonder why anyone would ever want to rip BluRays.