Is Atmos for Audiophiles?

By: Andrew Quint

If you’ve spent much time visiting online audiophile sites lately, you could get the impression that immersive audio is the future of the hobby. Exactly what’s meant by “immersive audio” isn’t always clear. In 2018, the AES sponsored a textbook called Immersive Sound with expert-authored, math-heavy chapters on topics that included binaural audio, surround sound, wave-field synthesis, and object-based audio. It’s the last of these that, in enthusiast circles, has become synonymous with immersive audio and, although there are other formats that are object-based—Auro-3D, MPEG-H, DTS-X, Sony 360 Reality, and others—it’s Dolby Atmos that’s been dominant when it comes to yet another attempt to represent the spatial aspects of recorded sound.

“Yet another attempt?” Well, this is an area of audio engineering with a rich history and, strangely, a large part of Dolby Atmos’s small but ardent audiophile constituency doesn’t seem to have much experience with or even much interest in earlier approaches to spatial sound. Commercially, that history dates back more than half a century to Quadraphonic—four channels, in contrast to the two of stereo (a misrepresentation, as the term “stereo” was originally intended to refer to more than one.) Next, by way of technology originally developed for movie theaters, came “surround sound” that evolved into the physical media that many multichannel music aficionados view as the high-water mark for spatially ambitious music software—the short-lived DVD-Audio format, SACD, and music-only Blu-ray. I have thousands of these albums, on both disc and drive. Especially with classical music, the best can capture the experience of hearing a performance in a specific venue. With “synthetic” studio recordings of jazz, rock, and other popular genres, the results are mixed, but many are highly enjoyable, not just for their enveloping spaciousness but also for their capacity to clarify an artist’s musical intent.

Like stereo, traditional multichannel is loudspeaker based. A dimensional soundfield is created by craftily routing sounds to a specific channel in a 5.1 or 7.1 configuration. With object-based formats, some sounds, saved as mono files, are only distributed at the time of playback based on how a listener’s audio system is configured. There is also a standard multichannel “bed” that includes height channels, on which the objects, guided by their accompanying metadata, are superimposed. It’s obviously a wonderful tool for filmmakers and video game programmers when jets are flying overhead, bullets are whizzing past, or there’s some other “special effect” to portray sonically. Some recording engineers have leveraged the possibilities of Atmos (and other object-based formats) for musical content with excellent results, and some examples are noted below. Unfortunately, this isn’t what the typical Atmos-loving audiophile is listening to right now.

The Editor-in-Chief of this magazine has an audio aphorism I’ve heard him offer up more than once, applicable to new and/or controversial technologies that people want to weigh in on: “If you haven’t heard it, you don’t have an opinion.” In fact, too often, audiophiles are happy to take sides on matters of sound quality without the benefit of listening to the equipment or recording in question.

I wanted to be certain that my opinion of Atmos, whatever it was, wasn’t predetermined, based on brief auditions at an audio show or on a friend’s system or, worse, on word-of-mouth. I wanted it to be based on spending a meaningful amount of time with the technology in a familiar environment. This meant obtaining some new gear, but I wasn’t, of course, starting from scratch. I had a good 5.1 surround-sound system and a lot of positive experience with multichannel music. The loudspeaker array was all-Magico—M2s for the main fronts, an S3 Mk2 for the center channel, S1 Mk2s for the surrounds, and an S-Sub subwoofer. To add Dolby Atmos compatibility, I purchased the Magico A1s I’d just reviewed and made those my height speakers. They were mounted on the side walls, even with the main listening position, their bottom surface six feet above the floor. My AV receiver for multichannel listening had been an Anthem D2v, old enough that it lacked modern surround protocols like Atmos; I replaced it with an Anthem AVM70. For power amps, I was all set—Tidal Audio Ferios monoblocks for front right and left and Pass Labs for the rest: three XA60.8s for center and surrounds and an Aleph 0s for the height speakers.

Source material came to the system in three ways. Discs—CDs, SACDs, and Blu-rays—were played on a Sony X1100ES universal player connected with HDMI to the Anthem. Stereo Tidal files were run through a BACCH-SP adio with a proprietary crosstalk cancellation (XTC) filter that could be turned on and off, the digital output then sent on to the AVM70 though a coaxial cable. Finally, an Apple TV box brought in Atmos material that was sent directly to the Anthem via HDMI.

In reality, there’s very little music-only Dolby Atmos material available on silver disc or download. Most of what you can hear now—thousands of songs—is available from streaming services, including Tidal, Qobuz, Amazon Prime, and, especially, Apple TV+. The variety of music available is gradually increasing—nothing like the tens-of-millions of tracks available from the major streaming services, but increasing—and the price for a subscription is quite reasonable. However, there’s a substantial problem that’s not mentioned much by Atmos partisans. There are two varieties of Dolby Atmos, a lossless one called Dolby True HD which is what you can get on a disc or download, and a lossy one, Dolby Digital Plus that’s streamed for reasons of economy. And Dolby Digital Plus isn’t just a little lossy; it’s profoundly so—the data rate is roughly half that of a Red Book stereo CD.

How do those lossy files sound, apart from their surround aspects? When compared to the same material in stereo from Tidal or Qobuz, where what’s offered is at least CD-quality and often better, not great. I did many comparisons and, though at first a listener may be seduced by the spatiality of the Atmos material, when he or she concentrates on color, texture, detail, dynamic nuance, and other “reality triggers,” the Atmos version usually comes up short.

A few examples. On the Apple TV+ Atmos version of Sheryl Crow’s “Every Day Is a Winding Road,” the bass is a series of dull thuds as opposed to the file available from Tidal, where it’s full, rounded, and tuneful. It’s far easier with the higher-resolution stereo file to tell when Crow is double-tracked with herself. Tenor Daniel Behle has received accolades for his live portrayal of the title role in Wagner’s Lohengrin. When his performance (on the Prospero label) of the Act 3 showstopper “In fernem Land” is heard via Atmos streaming, the singer impresses, but compared to the same performance heard streamed from Tidal, his performance via Atmos feels restrained, with significantly less texture, dynamic shading, and “ring.” Nemanja Radulovic’s playing of the Beethoven violin concerto on a new Warner Classics release goes from pleasant with Apple TV+ Atmos to vital with Tidal. The powers that be at Apple Music have made it pretty clear that they have no interest in streaming higher-resolution content, maintaining, probably correctly, that the vast majority of their subscribers don’t care.

There’s a second issue for me, and it’s a big one. The quality of the spatiality provided by Atmos of the Dolby Digital Plus variety is often inferior to that with traditional 5.1 surround sound. Because the spatial treatment of pop, rock, jazz, and other non-classical genres is such a mixed bag, I developed this opinion mostly with classical. Atmos is “immersive,” all right, in the sense of filling the room, but there’s a generic quality to the spaciousness that becomes tiresome after a while. There’s little of the differentiation of recording spaces that good speaker-based multichannel can provide and less detailed information about the disposition of the musicians on an imagined stage before you. The kind of specific information about concert halls, performers, and recording techniques that I’m used to with traditional multichannel just isn’t forthcoming.

Dolby Atmos, the TrueHD variety, can succeed phenomenally. I have in my collection about three-dozen Blu-ray discs with Atmos production, most of which are from the Norwegian 2L label. Those releases hold both a high-resolution 5.1 PCM version of the program, and a True HD Atmos version. Two especially wonderful ones deserve mention. On Himmelborgen, Morten Lindberg has recorded a top Oslo choir with organ accompaniment in the church at which they’re based. The 5.1 24/192 DTS is very impressive, but the Atmos version is truly jaw-dropping with a wider and taller soundstage that gives the sturdy hymns an even greater majesty. As in life, one can identify individual voices within the much larger ensemble. On Ole Bull’s Largo posato e Rondò capriccioso (the opening selection on 2L’s Stages of Life), the solo violin has better focus and more specific localization. These—and other Lindberg recordings—are among the best spatial recordings in any form and demonstrate beyond any doubt that Dolby Atmos is capable of serving as a state-of-the-art encoding modality.

Besides the 2L releases, where the repertoire is far from mainstream and the spatial aesthetic is as immersive as it gets (session photos often show the musicians in a circular arrangement, surrounding the conductor and microphone array), chances to compare an Atmos Dolby Digital Plus version to a traditional multichannel mix are few and far between. But examples do exist, and the contrasts can be instructive. A number of Elton John’s best-known albums were reissued by Universal as SACDs with a multichannel option, including the 1972 classic, Honky Château. On the Atmos mix of “Rocket Man,” David Henschel’s majestically baroque synthesizer solo accompanying the second half of the second verse (“And all this science I don’t understand…”) is barely audible and Elton’s bounding piano part is indistinct. The “oohs” and “ohs” behind the listening position are more prominent and, arguably, taller with Atmos, but the soundfield is not as dramatically vast. The sense of a solitary man alone with his thoughts in the cold vacuum of outer space is lessened with the Atmos stream.

Another path to improved spatialization is to maximize the potential of two-channel stereo. The most fruitful approach has been crosstalk cancellation (XTC), and there are several products that can reduce acoustic crosstalk, including Theoretica Applied Physics’s BACCH-SP, which I’ve been using for well over a year now. On a new Deutsche Grammophon release of mandolin concertos performed by Avi Avital and Il Giardino Armonico, the hall ambiance on the Apple TV+ Dolby Atmos version sounds suspiciously cavernous for an ensemble of 20 players plus soloist. The intimate scale of the music-making was far better represented by a Tidal-sourced stereo file, especially with XTC engaged to reveal details regarding the location of the players relative to one another—an intimation that the musicians were interacting and not performing for a distant, unseen audience up in the cheap seats.

Why do I value the spatial aspects of canned music? One reason, I’ll admit, is a kind of nostalgia. Recordings with good imaging and soundstaging capabilities can take me back to a much earlier time in my musical life when I played trombone in orchestras and keyboards in a cover band. There they are, reanimated from the past: trumpets to my right, bassoons and clarinets in a row directly in front of me. Further in front, cellos are stage left and violins stage right—maybe a nine-foot concert grand between them for a concerto. Alternatively, I’m transported back to a sweaty basement with the drummer a few feet away, moving air with his kickdrum that the bass player and I, with left hand octaves on an electric piano, strive to support. An “immersive” presentation can certainly evoke the participatory sense of making music with others. More passively, it can also approximate the perspective of an audience member in a small club, a large concert hall, or an outdoor venue—the proverbial best seat in the house.

But I believe what we want to be immersed in isn’t a luxuriant wash of sound-for-sound’s-sake, but the musical meaning communicated by that sound. At least I hope we’re not simply looking for an intoxicating aural sensation that’s generalized from genre to genre, from artist to artist, and from venue to venue. That gets old very quickly.

With its capacity to dynamically locate specific images in a dimensional aural bed, Atmos can become awesome. But as currently experienced via the participating streaming services, it’s no better than episodically interesting, diverting…pleasant. If that’s what floats your boat as an audiophile, by all means spring for the necessary processor and extra speakers and prepare for a battle over aesthetic considerations in your listening space. For me, “pleasant” doesn’t cut it. In my personal quest to extract the spatial essence of musical sound, I’ll continue to pursue speaker-based multichannel as well as efforts to optimize playback of the millions of stereo recordings that are our collective inheritance. Dolby Atmos, as it’s mostly being offered now, is not a step forward for critical listeners looking for musical connection that rivals the real thing.