The madness of Dolby Atmos for music

  • “When your world is full of strange arrangements
    And gravity won’t pull you through
    You know you’re missing out on something
    Well that something depends on you”

    So runs the opening verse of ABC’s “The Look Of Love”, the third hit single from the band’s 1983 debut album The Lexicon of Love, which is about to get its 40th-anniversary treatment in the form of a half-speed vinyl remaster and a Blu-ray disc (but no CD). The Blu-ray contains stereo, instrumental, DTS-HD and Dolby Atmos remixes, all created by Steven Wilson.

    From Wikipedia: “Dolby Atmos is a surround sound technology developed by Dolby Laboratories. It expands on existing surround sound systems by adding height channels, allowing sounds to be interpreted as three-dimensional objects with neither horizontal nor vertical limitation.”

    If we want to tap into Wilson’s Dolby Atmos mix at home, we’ll need to wire up seven ear-level loudspeakers – two fronts, two rears, two sides and one centre channel – plus one subwoofer and two loudspeakers in the ceiling. Yes, the ceiling — for Atmos’ object-based height component. This setup is called 7.1.2. An Atmos mix will play on an existing 5.1 surround system but without the all-important height component.

    Of course, we can skip the ceiling speakers in favour of upward-firing speaker modules that sit atop our existing fronts and/or rears. These exploit ceiling bounce to cover off Atmos’s height component. But there is no universal ceiling height. The higher the ceiling, the greater the audio signal’s time delay. The greater the time delay, the later sound arrives at the ear. And then we have to ask: just how close are these phantom speakers to those of a proper Atmos system? If the result is supposedly indistinguishable from a 7.1.2 system, why bother with a real Atmos system?

    But wait, we also need a Blu-ray player, a Dolby Atmos-certified decoder and an amplifier setup with enough connectivity to send audio to each of our ten loudspeakers. And perhaps the biggest challenge of all lies in routing the speaker cable so that it remains out of sight. This is where audio enthusiasm crosses over into home renovation.

    Now for our first question (which isn’t for movie buffs): would you wire a 7.1.2 audio system (or 5.1.4 or other combination) into your lounge room just to hear The Lexicon Of Love remixed as a Dolby Atmos experience? It’s a definite no from me. Wilson could transform ABC’s debut album into a come-to-Jesus moment and that ‘no’ would hold fast.

    Supplemental question: would you be swayed by the argument that you’ve not heard what ABC and/or producer Trevor Horn intended (with this now 40-year-old record!) until you’ve heard it in Dolby Atmos? For me, once again, it’s a hard nope. And I love this album in its stereo incarnation. The menacing intro to “4 Ever 2 Gether” still ranks as one of the strangest to grace a pop song and that slap bass is strong enough to make Seinfeld fans sit up and take notice.

    As an aside, the original CD master of The Lexicon Of Love scores DR14 on the dynamic range database but its 2004 remaster dials that back to DR10. The higher the DR score, the greater the difference in perceived volume between the quiet and the loud sounds. (In 2023, we don’t yet know what Steven Wilson will do to this album’s dynamic range).

    No matter how good Wilson’s Atmos remix – and I’m sure it’s fantastic – having to wire in an additional eight loudspeakers (seven if I’m already running a subwoofer) just to enjoy one album in an alternative version is – I’m sure you would agree – madness.

    If we buy the newly-announced ABC Blu-ray as a standalone disc from Super Deluxe Edition – instead of the one that ships with the 4LP box set – we lose the promo videos but pick up the original album mix in hi-res stereo. This is the latest in a series of Blu-ray discs from SDE (the label) that, among other things, offers a Dolby Atmos remix of a new or classic album. Other titles include Orbital’s Optical Delusion, Brian Eno’s Foreverandevernomore ‎and Tears For Fears’ The Hurting.

    But even with all twelve of SDE’s Blu-rays sitting on the shelf, only the most committed of listeners would rewire their lounge room in order to access those discs’ Atmos mixes and to sit at the extreme end of hardware-first audiophilia. Their newly installed Dolby Atmos system would only be good for a dozen albums. Would you buy a new pair of loudspeakers if you only had twelve albums in stereo? I wouldn’t. This isn’t to pour cold water on Steven Wilson’s or SDE editor Paul Sinclair’s efforts but to lend them broader context. The more we spend on playback hardware to hear a dozen or so albums in a new format, the more the tail wags the dog.

    If we hunt and peck for Atmos-loaded Blu-ray discs out on the Internet – beyond the scope of the SDE store – we might see our collection grow to fifty. In doing so, we would say hello – once again – to The Beatles’ Abbey Road and INXS’s Kick. And yet the stiffest challenge in sticking to Blu-ray-hosted Atmos mixes is that we might not reach a hundred discs before our demand outstrips supply.

    Are one hundred discs enough to justify a Dolby Atmos system overhaul? Set against the backdrop of almost 80,000,000 songs available to stream for US$10/month – songs that are already fully compatible with an existing two-channel rig – I say no. One hundred albums as Blu-ray discs are woefully insufficient for me to justify adding seven more loudspeakers to my listening space.

    Some of you be asking right now, why bother with Blu-ray discs at all when Tidal and Apple Music both stream immersive audio content? As Paul Sinclair points out, the discs are the only way to access lossless versions of the Atmos mixes contained therein. Any Spatial Audio equivalent offered by Apple Music, or the 360 Reality Audio served up by Tidal, will be heavily compressed with a lossy codec.

    From Digital Trends, “First, a quick 101 on how Dolby Atmos (for both music and movies) works. Dolby supports two flavors of Dolby Atmos. Dolby Atmos via Dolby Digital Plus is the lossy flavor. It’s designed to provide the Atmos experience, but at a lower bandwidth, so that streaming video and music services can stream Atmos without incurring huge data fees. If you like to listen on your phone, it also keeps your mobile data costs from going through the roof. If you’ve watched a movie in Dolby Atmos from Netflix, Disney+, or Apple TV+, you were listening to Dolby Digital Plus.

    According to Dolby Labs, Dolby Atmos audio in Dolby Digital Plus is usually encoded at bit rates between 384 and 768 kilobits per second (kbps) [my emphasis]. To put that in perspective, lossless, two-channel CD-quality stereo in FLAC format uses 1,411 kbps — twice as much data as lossy, multi-channel Dolby Atmos via Dolby Digital Plus.

    The second flavor of Dolby Atmos is via Dolby TrueHD, a lossless, hi-res-capable audio format that is used on physical media like Blu-ray discs and digital downloads of Dolby Atmos Music from hi-res music sites, where its higher data requirements are less of a concern.”

    Bit rates for Dolby TrueHD fluctuate with the audio being encoded. Dolby Atmos averages around 6,000 kbps when a 48kHz sampling rate is used. But Atmos can be encoded losslessly at up to 24-bit/192kHz, which results in bit rates that can soar as high as 18,000 kbps. We’ll do the math: that’s between 780% and 2,300% more data than Atmos via Dolby Digital Plus.” 

    From a bitrate perspective, Apple Music’s Spatial Audio content is to Blu-ray-hosted Dolby Atmos what Spotify is to hi-res stereo streaming. That makes intuitive sense: Spatial Audio streams must be compressed enough to traverse the wireless gap that straddles smartphones and headphones where Bluetooth transmission caps digital audio streams at around 1000kbps.

    Now we must ask: how close does a headphone’s binaural take on Dolby Atmos get to the same album played back via a properly configured 7.1.2 speaker system in a room? And therefore: is it really Atmos? Flipping that question on its head, if Apple Music’s Spatial Audio is just as good as in-room Atmos, why bother with speakers?

    Atmos mixes are made in studios with ten (or more) loudspeaker channels. That means the quality of the Atmos listening experience further rests on the technical/artistic know-how of the studio bod charged with creating the remix. Do they take the time to hear if and how their loudspeaker-derived mix translates to headphones? In an ironic twist, any headphone-based binaural conversion is, by definition, not as the artist (or remixer) intended.

    Click to animate!

    Headphones aren’t Atmos’s only physical challenge. Soundbar manufacturers want us to believe that a tube containing a multitude of drivers, a sub and a pair of wireless rear channels can approximate 7.1.2; that the soundbars’ side- and upward-firing drivers can successfully exploit wall and ceiling bounce to deliver the illusion of sound height that is fundamental to the Atmos concept. If faking ceiling and wall speakers with reflected sound works as effectively as many manufacturers claim, why bother with real ceiling and wall speakers?

    My own experience with the €900 Sonos ARC was a major disappointment. Listening from my couch, I was here and the sound was over there. Worse: the ARC’s clipped the beginning of each song as I skipped through an Apple Music Spatial Audio playlist, presumably because its decoder needs half a second to wake up. It couldn’t even do gapless playback with Apple Music Spatial content. YouTube commenters responding to my frustrations pointed out that my listening room’s acoustic treatment could be hindering the ARC’s reflective surface dependencies. The upshot is that a reverberant room remains a prerequisite for a soundbar’s phantom speakers to appear and yet room reverberation in the midrange and treble is fundamentally detrimental to the sound quality of any loudspeaker system.

    Let’s pause to take in someone else’s opinion. On the hardware side, if we want the full-fat Dolby Atmos experience at home, we need to install a 7.1.2 system: ten loudspeakers, ten amplifier channels and an Atmos-capable processor.

    Soundbars and their associated surround speakers give us an approximation. Ditto upward-firing add-on modules. Headphones? Nope. Just ask electronic musician and YouTuber Benn Jordan whose video on this subject is a must-watch:

    We could argue backward and forwards about the talents of the studio engineers creating Atmos mixes or the efficacy of soundbars + surrounds (or headphones) in relaying them (“as the artist intended”) to the listener but the bigger issues that follow are undeniable.

    Per previous attempts at elevating format quality, Dolby Atmos is, once again, asking us to re-buy our favourite albums dressed up once again as The Next Best Thing™. We’ve been here before, many times over. The Next Best Thing™ of yesteryear – SACD, DVD-A, DSD and MQA – all demanded that we buy our albums again and new hardware to play them. Where are those formats now?

    Perhaps the closest relative to 2023’s Blu-ray Dolby Atmos disc is the ‘High Fidelity Pure Audio’ Blu-ray audio disc, which contained hi-res PCM and 5.1 DTS HD Master Audio and Dolby TrueHD content. These discs were launched to great fanfare in 2013 and then quietly discontinued in 2016. Not even the audiophile market could sustain them. Another Next Best Thing™ format gone bye-bye.

    I’ve witnessed three successful digital audio revolutions in my lifetime: the CD (that wiped away vinyl’s surface noise and a tape’s hiss), the MP3 (that put a thousand songs in our pockets) and lossless streaming (that brought the CD store home). Each of those formats had one thing in common: they added convenience or, at the very least, took none away. We now live in a streaming world where Dolby Atmos’ lossless demands on bandwidth, data usage are simply too great for most end users and streaming services to bear.

    Back to the Digital Trends primer: “Bit rates for Dolby TrueHD fluctuate with the audio being encoded. Dolby Atmos averages around 6,000 kbps when a 48kHz sampling rate is used. But Atmos can be encoded losslessly at up to 24-bit/192kHz, which results in bit rates that can soar as high as 18,000 kbps. We’ll do the math: that’s between 780% and 2,300% more data than Atmos via Dolby Digital Plus.”

    In 2023, we have to make peace with immersive audio streaming being lossy. And I have to wonder how many bleeding-edge audiophiles already titillated by Atmos will be down with that, especially those who railed so hard against MQA’s lossy behaviour. As of right now, lossless Atmos content can only be delivered by discs and downloads, of which there are vanishingly few. Not even a thousand lossless Atmos releases could wipe away the stains left by its inconvenience and expense. And they say vinyl people are crazy!

    Convenience is the calling card of mainstream uptake. Dolby Atmos playback at home is the epitome of inconvenience: it forces us into a multi-channel array of loudspeakers or to maintain a reverberant room for a soundbar’s facsimile. Headphone listening squeezes the immersion down to two drivers but leaves many asking questions about how close it is to ‘real’ Atmos and if it will work with their smartphone, streaming service or headphones. Audio folk who insist on the highest sound quality and who are repelled by ‘Spotify’ and Bluetooth will find little to satisfy their lossless Atmos demands over at Apple Music or Tidal.

    This brings us to the biggest inconvenience of ’em all: Dolby Atmos-loaded Blu-ray discs and downloads, as good as they may sound, are so uncommon that for this listener, the juice just isn’t worth the squeeze. It might be obvious to some but I’ll underscore it for clarity: headphones and soundbars aside, my criticisms of Dolby Atmos have nothing to do with its sound quality and everything to do with its setup complexity, the heavy data compression used by streaming services and, once we move away from Apple Music, the paucity of lossless content.

    I now find myself surveying a ‘new format’ landscape that echoes the advent of DSD where a handful of early adopters are making a lot of noise online about not very much in the way of music and the thousands of titles from major labels needed for broad/er format adoption just aren’t there.

    Given the studio time needed to create an Atmos mix, is it realistic to think that Sony, Universal and Warner will commission Atmos mixes of more than a few hundred legacy titles per year? And even if new release titles landing as Spatial Audio on Apple Music continue apace, it will be years until their number grows to represent more than, say, 10% of all that’s available in stereo on the platform. But Apple Music streaming brings us back to the compromises of heavy lossy compression with the addition of binaural conversion for headphone listeners.

    I have no doubt that a good Dolby Atmos mix heard through a properly set up ten (or more) channel loudspeaker system does sound incredible — but I’m not into audio to improve the sound of a hundred or so albums. I’m interested in audio tech that will improve the sound of – or access to – an entire music collection. The CD did that. The MP3 did that. CD-quality streaming did that. Dolby Atmos? Gravity won’t pull it through.


    • Installing a 7.1.2 (or better) Dolby Atmos loudspeaker array at home is a major undertaking
    • The Soundbars and upward-firing speaker modules that exploit wall and ceiling bounce to approximate Atmos’s height component rely on the presence of room reverberation, which in turn opens the door to bad sound
    • Headphones dodge room reverb but with Atmos they boil the immersive content down to a binaural facsimile of 7.1.2 in-room playback
    • Apple’s Spatial Audio and Tidal’s 360 Reality Audio immersive audio streams are heavily compressed with lossy codecs
    • The library of Blu-ray discs and downloads containing lossless Atmos content numbers hundreds, not millions

    Written by John

    John currently lives in Berlin where he creates videos and podcasts for Darko.Audio. He has previously contributed to 6moons, TONEAudio, AudioStream and Stereophile.

    Darko.Audio is a member of EISA.

    Follow John on YouTube or Instagram

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