Saturday 20 January 2024

On Stereophile's "Dolby Atmos: A Bleak Shadow?" - really? 🤔


I saw Stereophile's "Dolby Atmos: a Bleak Shadow?" article the other day. Honestly, I found it a bit irritating. The ideas seemed poorly contextualized with little background or meaning for what I imagine would be the average audiophile reader. It basically consisted of hearsay-level cherry-picked concerns as if these are significant (including that title).

Let's be clear about this. It's not like any of us must or even should love Atmos or multichannel. We can easily get through a lifetime of music enjoyment with 2-channels. Even though I like and even prefer multichannel/Atmos for many of my albums, it's just an option for those like myself who want to explore the surround-sound music experience as a superset of modern audio reproduction technology. Some artists and audio engineers these days are also exploring the extensive flexibility and ways to best create the mix. So if a traditional audiophile magazine believes that staying at 2-channels is all that's needed, well that's fine. But one doesn't have to write articles that seem to be trying to induce some kind of emotional response, stirring intrigue or concern even in just that title. (These days, sound bites and headline titles might be all that many pay attention to.)

So what do you mean by "bleak shadow", Mr. Lindberg (as reported by Jim Austin)? Are we talking just about numbers like bitrate going down when a lossy stream is delivered to the consumer, or are we implying that sound quality changed significantly in a negative, "bleak", way? If it's only bitrate reduction, that's totally fine, isn't it? Since the consumer isn't keeping the data, there's no point wasting network bandwidth! Streaming services like Netflix or Disney+ all stream lossy video and audio. Many customers, I'm sure including discerning ones, will not complain if they understand the nature of the technology and the quality limits depending on how it's consumed.

If Lindberg and Austin are talking about sound quality though, do you not think there's some hyperbole in that headline? Is it really that bad or is this just FUD being fed to audiophiles, stirring more anxiety than honest concern? Maybe Stereophile is just trolling and needed a headline like this as click-bait - I see their forum section has disappeared without notice recently, so maybe this can boost traffic.

If we are to try a blind listening test between 768kbps lossy EAC3-JOC Atmos and 24/48 TrueHD lossless Atmos (with the same 5.1 bed channels) of actual music, I wonder whether writers and readers of Stereophile would be able to show a clear preference; and if that preference is even for the lossless TrueHD! There are examples in the past to suggest that it would not be very noticeable. For example, 320kbps 2-channel MP3 sounds great compared to lossless CD and 16-bit vs. 24-bit is usually inaudible (TrueHD typically at 24-bits and EAC3 decodes to 16-bits). As for multichannel 5.1, back in the DVD days around Y2K, there were listening tests between lower-bitrate AC3 (384-640kbps common back then) compared to DTS (1.5Mbps) and as far as I can recall (can't find an old link that works still), despite DTS' 2-4x increase in bitrate, though generally consider superior, it wasn't a slam dunk and 640kbps AC3 was generally considered equivalent to DTS once level matched. The concept of "diminishing returns" does not only apply to hardware price-to-performance, but also to bitrates of psychoacoustic perceptual audio codecs.

Fast forward 20 years to multichannel music streaming today. EAC3 is a more advanced version of AC3 released around 2004 said to be perceptually equivalent at lower bitrates (Dolby at one time suggested 192-256kbps EAC3 is equivalent to 384kbps AC3 for basic 5.1), and the bitrate with Apple "Spatial Audio" and other services is at 768kbps which is a reasonable number for high-quality music content. By the way, EAC3 can in fact scale beyond 5.1 (up to 15 full-band channels) and up to 6Mbps if ever needed even though currently the services are capped at 768kbps 5.1 with Atmos metadata (JOC).

I've always found it interesting what audiophile magazines choose to focus on when it comes to numbers and technical details. So, they think it's "bleak" that multichannel is streamed at 768kbps rather than Lindberg/2L's "... Dolby TrueHD bitrates average around 6000kbps with peak data rates up to a maximum of 18,000kbps for high sampling rate multichannel content"? What's the big deal?

I think it's ironic that a more objective-focused audiophile like myself would have to remind subjective-leaning Stereophile to be careful about judging "good" or "bad" based on just numbers. Did they actually listen to the music or just want to obsess about numbers?!

As discussed over the years, big numbers like lossless 24-bit/192kHz were never that amazing when we listen and do A/B comparisons with lesser samplerates or bit-depths. I think it's great that 2L captures the sound at 24/352.8 and can archive at this data rate, translating this to high bitrate TrueHD for their Blu-ray releases. However, this kind of hi-res specification might have been impressive 10 years ago when we were starting the hi-res journey, but not in 2024 since we know from experience now that hi-res is not audibly revolutionary even if subtly better compared to good CD at 16/44.1.

If we care about numbers having audible significance, why doesn't Jim Austin focus on some real hi-fi inadequacies like the fact that LPs only have at best ~70dB of dynamic range, and maybe -30dB crosstalk with a good phono cartridge. These and other fidelity issues with vinyl are even audible across YouTube lossy streams despite sometimes using obscenely high-priced gear as discussed last week. Surely, that's more of an inconvenient truth for many audiophiles than this minor EAC3 bitrate nitpick! As you know, many of the products reviewed in Stereophile are for vinyl playback and thus susceptible to such levels of poor performance regardless of price. Where are the "As We See It" articles lamenting that many audiophiles are stuck with listening to such poor quality media in the 21st Century?!

I hate to say it since it's 2024 and I was hoping not to bring up the dreaded three-letter acronym, but feel I have to given the prominence of Morten Lindberg's quotes in the article. Did he notice what happened to the data rate from his precious 24/352.8 2L hi-res masters when he declared his love for MQA? It went down 8:1 with lossy MQA files, and that's only with 2 channels before further lossless compression.* Was the MQA file not also a "bleak shadow" of his hi-res master? Did he complain then?

[*With multichannel music, surround channels can be low level, sometimes there's no center channel content, and the LFE channel is bandwidth limited or even not used. Furthermore, multichannel albums have less dynamic range compression. As a result, we can often see better compression ratios with multichannel recordings than 2-channel. This is to be expected even with lossless compression.]

So, in recent audiophile history, Lindberg could have championed for lossless hi-res and instead sold out to MQA. He even presented a positive spin in the bankruptcy announcement. I'm afraid his name is linked to that money-losing, lossy scheme that nobody asked for, so forgive audiophiles like myself for questioning Lindberg's credibility when commenting about codecs! Nonetheless, congrats on the Grammy nominations and win. Awesome. For the record, I did say 2L recordings are some of the best for Realism recently so I think I'm still very fair to Mr. Lindberg.

BTW, I see 2L still charges MQA stereo files at full lossless hi-res prices; they might want to consider changing that after all these years.

Unlike the questionable FUD around bitrate numbers, the jump from 2-channel to multichannel immersion, and the improved dynamic range of "Spatial" albums (including when downmixed to 2 channels) are definitely audible and likely beneficial for enjoyment assuming the music was produced well. Listen and decide for yourself.

One last thing from the article. Austin writes: "... this form of Atmos supports up to 128 virtual channels" as if to impress upon us how much content there is (oooohhhh, 100+ channels!) considering the bitrate cap. The 128 virtual channels are actually objects plus bed content that can be imported and manipulated dynamically in the Atmos audio workstation. In the final Atmos render and encode, whether lossy EAC3 or lossless TrueHD, these objects are "clustered" down with detailed positional/level information defined as metadata. At most, even TrueHD can have "only" up to 16 lossless PCM channels which can be manipulated by metadata to represent the final rendered content +/- center with LFE, +/- surrounds, and +/- height channels. Ultimately, the authored Atmos file is "lossy" whether as EAC3 or TrueHD since neither contain absolutely 100% of the full-quality master as defined in the Dolby Atmos Master ADM file.

No doubt, there's plenty of fancy DSP happening in AV receivers and surround processors! Don't be afraid dear rational audiophiles, DSP is the present and the future of hi-fi audio.


In Summary...

IMO, there's nothing to be concerned about. Sure, the 768kbps EAC3+JOC Atmos stream will sound subtly different, but far from a "bleak shadow" of TrueHD-Atmos quality wise even if 10+:1 compressed down from the TrueHD or ADM file. 😂 I've done some Atmos editing and conversions over the past year and listened for myself already. Maybe at some point I'll put some demo material out for audiophiles to have a listen.

Absolutely, we can and should advocate for higher bitrate TrueHD-Atmos versions of favorite albums for our collections. For the ultimate Atmos multichannel audiophiles, maybe they can even grab some truly lossless Atmos Master ADM files (300-800MB/track, ADMs cannot be streamed)! Perhaps in time the streaming services can transmit TrueHD-Atmos as well, but for practical reasons, I don't see that as a priority in 2024 just like 4K resolution isn't necessarily a high priority for many of us with Netflix accounts even though modern Internet speed can accommodate it (the 1080P tier is enough for me even with multiple 4K displays at home, but I will happily buy the 4K UHD Blu-rays for my favorite movies).

Whether music labels and companies like Super Deluxe Edition issue more Blu-ray multichannel/Atmos albums would be a matter of economics, driven by demand. Likewise hardware developments catering to multichannel can only grow if there's interest. I guess traditional magazines like Stereophile and TAS don't seem to be encouraging audiophiles to demand multichannel/Atmos based on what seems like tepid interest and IMO unfounded negativity towards EAC3 multichannel streaming. If they want to stay within their 2-channel niche including promotion of vinyl and other sorts of anachronistic hardware (including tubes, wire ruminations, unfounded tweaks), so be it. However, that might not be a good attitude to take for the sake of growing the high-fidelity hobby going forward especially if the traditional 2-channel "high-end" side of the hobby stagnates and the vinyl "revival" declines (IMO, this is inevitable).

Enjoy the music folks! I think it's important to be more insightful and realistic than the typical audiophile magazine editorials with their undisciplined perspectives based on cherry-picked hearsay of supposed audiophile heroes, expressed with unnecessary dramatics.

20 comments:

  1. Thanks for another great article. A really important point that you've made previously about streamed/m4a Atmos music is that it typically does not have the dynamic range compression that one very frequently experiences with other digital music formats (e.g. CD or 24 bit 96 or 192 HD music downloads).

    I would much prefer to hear a lossy Atmos track (even if mixed down to 2 channels) to the same track that has been horribly dynamic ranged compressed and distributed in a high resolution format.

    A good example of this is The Rolling Stones' Hackney Diamonds. That album sounds MUCH better in the M4A Atmos format vs. the 24/96 uncompressed FLAC format (which comes in at DR5).

    ReplyDelete
    Replies
    1. Hey William,
      Yup, very much agree regarding the better dynamics in general and also Hackney Diamonds in particular.

      I find it amazing that audiophile writers like Jim Austin don't pick up important details like that in their columns or within the text of their various reviews (although admittedly I don't read everything they write). Imagine an "As We See It" article actually demonstrating that idea of dynamic range and telling audiophile readers about this rather than worrying about 768kbps!

      Now that would be a positive, educational article pointing discerning listeners to try something new they might not have thought about before. Bring up the fact that technology has progressed with hi-res DSP, encoding techniques, and new codecs that bring more nuanced content and immersion to the listener.

      IMO, change is good, necessary even to maintain vitality. I would hope respectable journalists can lead being in their position rather than become stagnant themselves. To talk about modern digital multichannel music openly and challenge some of the long-held audiophile mythologies around the quality of LPs, idealization of analog, or even fear of any kind of digital processing I think would be a breath of fresh air for both the younger generations of music lovers as well as challenge the ideas of the shall-we-say "more experienced" older audiophiles. :-)

      What still baffles me is the willingness for Stereophile and even Lindberg to jump on the MQA scam so quickly. Here's something that was DSP'ed, bitrates slightly higher than CD (yet claiming to deliver "full" 24/384 sound), lossy, also aimed at streaming, based on sketchy technical foundation... Yet these guys went for it! And now they can't appreciate that multichannel Atmos delivers immersion and improved dynamic range at reasonable bitrates!?

      The audiophile magazines are just strange... I think it fundamentally tells us that even the Editor like Jim Austin needs to take a step back and develop a deeper understanding of what they're writing about, develop a vision of what the magazine is about, and definitely stop digging deeper holes when he's simply wrong on many levels (and perhaps doesn't even know it yet?!).

      Delete
    2. I love multichannel, i love upmixing, don't give a damn about the supposed audible deficits of lossy. But i have to note that multichannel mixes are NOT guaranteed to be free of compression. Arch, get your hands on existing 5.1 mixes of Rumours or GoodbyeYellow Brick Road on Dvda, bluray, sacd. Throw some tracks up in a DAW. You're gonna see hecka compression in those front channels. But those mixes sound great!

      Delete
    3. Thanks Steven,
      You're right, just because it's multichannel does not ensure that the dynamics cannot be squashed. There are some rather unfortunate multichannel albums out there that sound bad. Indeed my 2003 release of Goodbye Yellow Brick Road on multichannel SACD has some rather squashed tracks. :-(

      Hopefully, these days with Apple's and other streaming services enforcing average loudness to -18LKFS for the multichannel mixes, it will at least make audio engineers think twice about engaging in the loudness wars again since it'll risk their music not achieve any actual volume gain compared to others while sounding less dynamically punchy because they're just going to be wasting headroom that other better audio engineers can capitalize on.

      Delete
    4. But I want to repeat: those two examples of 'squashed' still sound great. Just really good mixing work! I'll play "Bennie and the Jets" in surround to wow any skeptic.

      Delete
    5. Steven, May I ask what your using to measure DR of multich files now?
      I used to use Foobar but since my update to 2.0+ the DR component isn't compatible and AFAIK there's no new build. (Windows)
      I do have a 1.0.16 build on my Linux box but it fails on multich files.
      TIA, Sal

      Delete
  2. What a great post Archi, thank you for your support.

    ReplyDelete
  3. Hiya Arch!
    I read Austins article as late as today having just come back from another 2 weeks of work abroad and not had the chance to read my subscription. Throughout the years I have often wondered why I continue to subscribe to a publication I really could do just fine without. I suppose in part it is because of the tactile experience and that it occasionally provides some aha moments or piques my interest. Tired from working nights, my initial reaction was that the article was somehow supportive of multichannel, which did surprise me considering the magazine’s previous not-too veiled stance on the format. So, I re-read it and experienced a Stereophile aha moment. Yeah, not so supportive after all. Going back to your previous blog regarding immersive music, my reaction to the formats nay sayers has always been one of,” why ever not?”
    I have discussed this with many stereo enthusiasts and a common response is that although they enjoy the format for movies, they prefer two channels for music. Why? Because then they can listen critically and seriously. If you hear the reasons for why you need a multi-channel setup for your movie entertainment the argument is that without the format the movie experience is lackluster and dull. Odd that the two are so different.
    Reading Wikipedia: Surround sound is a technique for enriching the fidelity and depth of sound reproduction by using multiple audio channels from speakers that surround the listener (surround channels).
    I thought all audiophiles were constantly doing all and gladly paying for everything and anything to enrich the fidelity and depth of sound. Apparently though, not through an affordable multi channel setup. Reading the flowery language found in many of Stereophiles advertisements, this is to be found by investing in expensive cables. In this month’s edition we learn that by buying Wireworlds Platinum Starlight 8 Ethernet cable at 900 $ /meter we can “ recreate the most transparent, resolving, detailed, natural and immersive performance…” or as stated in the same ad by Andrew Quint who obviously knows a thing or two, “ voice at a level of purity previously unheard, utterly uncolored yet fully characteristic…” Good Gracious what utter nonsense.. Yet this seems to be the direction and investment publications like Stereophile want us to take in our pursuit of perfect music reproduction.
    On a personal note, I have found great enjoyment in that my WiiM Pro Plus now fully supports Roon.
    Thanks for yet another engaging article. Keep em coming!

    Cheers Mike

    ReplyDelete
    Replies
    1. Thanks for the comment and your experience Mike,
      Yeah, I've let my subscription lapse awhile back already so all I see are the Stereophile articles online now. Subscription is cheap and I guess the glossy photos can be enjoyable. So perhaps reasonable entertainment value.

      Indeed "why ever not?" be supportive of multichannel is a good question. I don't see there being any forced choice "win-lose" scenario here for those who personally might not consume multichannel regularly but recognizes that there's a market out there and some hi-fi enthusiasts (not just home theater folks) will spend the time, money, and effort to set up a good sounding system for this! Industry-wise this is good for companies whether it's developing a multichannel DAC, or amps that work well in multichannel rooms, or of course speaker companies...

      Likewise, I would much more likely look at a remix/remaster than yet another 2-channel remaster these days which is getting way boring. Recently I see Aja has been remastered "from the tapes" by Bernie Grundman... Do I really need another stereo copy? I don't think so. But if there's a well-done multichannel, maybe that could be interesting.

      It is funny that music enthusiasts and theater enthusiasts seem to differ on whether 2-channels or 5+-channels are better because of whether they can "critically listen". Do some prefer mono because that's even easier to critically listen for details? One criticism I've heard is that some complain about certain objective testing techniques for speaker quality (eg. Toole) only listening to 1 speaker. Isn't this then about the same if we only listen to 2 because that's "easier"?

      I quite enjoy listening critically to multichannel and evaluating the "Realism" of what I'm hearing or evaluating "Immersion" - whether some of the instrument placements and dynamic panning of sounds appear precise when I listen in multichannel. This extra dimension of critical listening (depending on the music) might be a new challenge and skill that audiophiles may get more comfortable at. A challenge for those audiophiles willing to step forward and try something new. And topics which I hope magazines can get interested in and talk about rather than just negativity as if there's nothing else worthwhile but 2 channels! IMO, that's very narrow, limited thinking.

      Delete
  4. Thanks Arch for that very knowledgeable answer to that Stereophile article that also bothered me. I stream Atmos (from Amazon) and I never had any impression of lossyness. On the contrary, when Amazon only offers an Ultra HD (24/96 or 24/192) or HD (16/44.1) version of a recording, I immediately hear a reduction in quality. Volume is lower due to only 2 channels being used, a lower dynamic range and the image is much thinner.

    I listen mostly to classical, and indeed records from 2L and trptk natively captured in multichannel are of the highest realism, even when streamed…I recently listened to this recording ( https://trptk.com/shop/downloads/abel-pieces-for-viola-da-gamba/ ) and, as an example of what a simple Sonos system can do (Beam soundbar, Sub mini, and passive surround speakers driven by a Sonos Amp), if I stand up in the sound bubble created, I can distinctly see the player further away and OVER the soundbar that is then at the level of my knees, below the tv screen…

    That article seems to equate only the bitrate with high quality, I say that psychoacoustic realism is much more due to a real-life 3D soundscape that stereo can’t produce, especially without crosstalk compensation.

    ReplyDelete
    Replies
    1. Absolutely Gilles,
      As usual, thanks for the music recommendations! I'll have to go track down that Pieces for Viola da Gamba album now :-).

      I truly hope Lindberg did not intend that his comment about bitrate values dropping be used in an article like this especially as the title the way it was presented! Surely he must recognize that with psychoacoustic encoding, the system is smart enough to compress the sound to maintain quality in a nonlinear fashion. That's simply basic understanding for anyone who spends a few moments understanding this over the last number of decades since the advent of MP3. I remember being astounded by the file size-to-quality ratio back in the early 1990's when I first downloaded an MP3 demo of some track by Madonna in university! Claims of this nature I would have expected to come from tech-know-nothing Neil Young a decade ago, not Lindberg.

      Whatever Lindberg intended with his comments, shame on Jim Austin for even writing and publishing this article, highlighting his lack of understanding. Maybe the Editor might want to double check his ideas in the future.

      Cheers and keep enjoying your system and exploring the potential of the Sonos!

      Delete
    2. Thanks Arch. Here are two more for your realistic 3D enjoyment: I suppose Apple streams them in Atmos like Amazon does:

      https://music.apple.com/it/album/alessandro-quarta-plays-astor-piazzolla/1650954728

      https://music.apple.com/us/album/certainty-of-tides/1706570712


      Delete
  5. Hi Gilles. Really enjoyed your recommendations. Especially " Certainty of tides" Orchestral jazz with a wonderful expansive sound. Cheers!

    ReplyDelete
  6. Dangit Archimago, you've got me thinking long and hard about this Dolby Atmos/Spatial Audio thing. I responded to a previous post of yours that due to money constraints and room size (10' x 12') that i probably would not be considering any sort of system beyond stereo. But now you got me thinking, what if I rethought my future 2 channels plans. I have a WiiM Pro feeding my, bought new by me, 1987 Yamaha Receiver and a pair of Ascend Acoustics Sierra-1s. I have been considering replacing the receiver with a miniDSP Flex and one of the available inexpensive class D amplifiers. This would give me a nice system to do some in-room measurements and PEQ to play with. And if I ever get into a bigger room, adding a subwoofer or 2 would be easy. Now I'm thinking, what if i buy an AVR instead (7.2) and just begin with the Dolby Atmos Height Virtualization with the possibility of adding speakers at a later date if a larger room becomes available. So, the question I have is have you listened to anything using Dolby Atmos Height Virtualization with a 2-speaker system, and what did you think? I really like the idea of the miniDSP flex but if I can do something similar (measurements and EQ with bass management) with an AVR, then maybe I could be convinced to go that route.

    ReplyDelete
    Replies
    1. Hi Joe,
      I was considering getting the MiniDSP Flex HT to replace my Outlaw AVP until I read the specs more carefully.
      Performance looks to be outstanding at any price, but the HDMI limitations are a killer for me. You can only connect HDMI to your ARC/eARC in/out on your TV. No problem, but the TV and any upstream sources need to be able to convert audio to uncompressed MCH. So it would work for Apple TV, which will perform that conversion, but wouldn't be able to handle any DTS, Dolby EAC, or Atmos inputs directly. Not good for my Sony TV.
      However, if computer is your main source (and you can output uncompressed MCH), the USB input would do you very nicely.
      I'd like to know what you decide.

      Delete
    2. Ha, if you're waiting for me to make a decision you'd better get comfortable. I've changed my mind dozens of times before I though I was all set with a miniDSP Flex and a small, Class D amp. No it'll take me months to determine if I want to go this other route. I don't currently have a TV in my office/listening room and my system will be primarily for listening to music with a WiiM Pro as my source.

      Delete
    3. Hey there Joe,
      Good to be thinking about the various options out there!

      I guess it depends on the device and speakers you're using Height Virtualization with if the results are to your liking. There's a "Virtual Height Filter" that can be applied to signals to create the psychoacoustic impression of sound floating above the head. You can see that in "Figure 9" and as applied to the ELAC Debut 2.0 A4.2 speakers I measured a few years back:
      https://archimago.blogspot.com/2021/01/measurements-elac-debut-20-a42-atmos.html

      Honestly, with 2 speakers there's probably not much you'll gain other than the higher dynamic range fold down I suppose of the multichannel mixes. However, good AV receivers IMO sound great and pricewise can really provide excellent "bang per buck" and yes, you will have the ability to upgrade your system when you move to a bigger room! :-)

      Delete
  7. Just to explain my experience of what happens after knowing Atmos: I'v got a decent stereo system, hard earned after all my life listening to the radio, tapes in mono, cheap all-in-one stereo decks... Now in my fifties I can, at last, listen to a nice setting and also have good headphones & earphones... I collect different versions of my favorite records masters... I listen to BIG stereo in my room.
    I bought a MacBook Pro, well capable of reproducing Atmos "effects" with its magically located speakers, spite the small construction of the device.
    I listen to music for fun... and, wow!, this Atmos thing is quite big fun and a pleasure!
    Since knowing, I've tried with a JBL sound bar to feel again the "atmos feeling"; it's no easy task: my MacBook does it much, much better!
    I'm poisoned; I can still enjoy stereo (and even some mono recordings are nicer than stereo mixes IMO)... BUT I think these Atmos mixes are wonderful, a joy for a music lover. I'll have to get a capable amp and speakers set. Again.
    I believe there's big confusion about Atmos because proper physical realization is not well standardized. Apple has put great care implementing the feature, which is really astounding when it's well presented. But I've tried different devices, and Atmos is not really working with them even pretending they are! It's tricky sometimes just with stereo, even with good equipment, because of positioning, room and other details. With Atmos, things are even more complicated. Nowadays, the only way to go is to spend a lot for a well made system. I miss affordable and decent Atmos implementations, and I would advice not to believe the compatibility tag that a lot of devices show, giving a very poor spatial effect.

    ReplyDelete