If you get the opportunity to test your assumptions, it’s always a good idea. Even when they are confirmed when tested, it’s still time well spent. Directly comparing consumer Atmos playback options against a Certified Dolby Atmos installation was one such opportunity for Julian. Find out what he heard and what if any surprises it held.

On a recent visit to Sensound, a Dolby certified Atmos studio in Worcestershire UK with Mike Exeter I had the opportunity to speak at length with owner/engineer Mark Gittins and to listen to some material in his excellent mix room. I’ve heard Atmos playback on good quality, properly set up monitoring systems many times before, though I don’t have an Atmos install at home. One of the really interesting things about this visit was the opportunity not only to listen to good mixes on a good system, but to compare formats. Mark’s studio is the only one I’ve experienced with so many delivery formats available for direct comparison. Running one of his mixes I was able to switch between stereo, 5.1, 7.1.4, 9.1.4 via his Neumann monitors, and stereo and binaural via headphones, and Apple Spatial via some AirPods Max. All by seamlessly switching between them on his DAD MOM. He could also play back Atmos material via a stunningly effective Sonos Era 300 Smart speaker.

Comparing Levels Of Immersion

Being able to compare the same material in the same environment across all these different formats was one of the most interesting listening tests I’ve done. Listening to a fairly static mix which didn’t use any objects which were being dynamically panned, the difference in immersion was what I was listening to and, unsurprisingly, the more speakers you run the more effective the immersion. However the real headlines for me were in the more domestic formats.

However good a certified Atmos install sounds, it’s unlikely that an Atmos mix will be heard over a similar system when it reaches the consumer, and to be relevant, Atmos has to be a transparent technology which doesn’t get in the way of the music. It’s not a trick for audiophiles to pore over, it’s a technology which, when used correctly, can make music sound better, and easier to listen to. For this reason the headphone mixes and the smart speaker were particularly informative, and something I’d not had the opportunity to directly compare before.

The mix sounded great on the monitors. The room is professionally designed, a floating room within a room with extensive, and very effective, bass trapping on the rear wall and minimal gear or clutter. A Mac Studio, A MTRX Studio, a pair of SSL UF8s and a UF1 and a single RND Portico Master Buss processor. Very pared down with the money spent where it matters, on the room. The KH310s are very familiar to me, they are the speakers I have at home and with these at L, C and R and the surrounds and heights all covered by the tiny but very capable DSP powered KH80 the mix sounded pin sharp in 9.1.4, with a noticeable loss of spatial fidelity dropping down to 7.1.4. The left wide and right wide speakers really do make a worthwhile contribution. It would have been interesting to compare 7.1.2 with 7.1.4 but to do this you would need to be in an install with 6 overhead channels.

Headphone Formats

Listening to the stereo downmix on Neumann NHD 30 headphones it sounded as expected - a good stereo mix. Switching to the binaural downmix I could use lots of subjective language to describe the difference but actually the important takeaway is that it sounded like the stereo mix but better and ‘easier’. Less crowded. It didn’t sound dramatically different and neither should it, it was after all the same piece of music.

Moving on to the Apple Spatial mix, the tonal difference between the open backed Neumann NHD 30s and the AirPods Max being used for the Spatial playback was fairly dramatic. The Apple headphones were bass-heavy and a little scooped. However the difference between an Apple Spatial mix and a Dolby Atmos binaural render is clear, with the a definite reverberant distance introduced to elements which were dry on the binaural render. For more on the reasons for this difference read our article Why Your Atmos Mix Will Sound Different On Apple Music.

Being able to compare Atmos binaural and Apple Spatial so conveniently was an excellent counter to the opinion that ‘Atmos sounds reverby’. It doesn’t but considering the confusion amongst consumers between Dolby Atmos and Apple Spatial Audio, it’s understandable how easy it is to reach that conclusion. Especially given the huge role Apple Music and Spatial Audio has played in bringing first hand experience of immersive audio to consumers.

Personal Head Related Transfer Functions

These listening tests were conducted without using a personalised HRTF. Having tried both the Dolby PHRTF and Genelec’s Aural ID I can confirm that in spite of being lucky enough to have an ear shape which works well with generic HRTFs, the additional acuity brought to binaural renders by using a personalised HRTF based on your specific physiology is very worthwhile. It would have been interesting to have heard the binaural renders using my PHRTF.

Atmos Via A Smart Speaker

As informative as the comparison of speaker formats and headphone versions was, perhaps the most interesting audition of the afternoon was hearing a Dolby Atmos certified monitor install using Neumann KH310s, KH80s and KH870 sub AB’d against a £450 Sonos ERA 300 Smart speaker. Mark had explained how he uses a combination of monitors, headphones and the smart speaker to check mixes and I’d been surprised that a smart speaker which relies on bouncing sound off the walls and ceiling worked at all in a studio space as dry and well treated as Sensound. The installed absorption, which does so much to improve the sound of the monitoring system, should reduce the effectiveness of a speaker like this. But the immersion it produced was really impressive. Nothing compared to the 9.1.4 monitoring but you’d hope not! Also on this particular mix, a straight ahead rock mix which didn’t contain huge amounts of bottom end, tonally the translation between the Neumanns and the Sonos was remarkable. It should be said this is a comment on how much like a professional monitor the Sonos sounds, not vice-versa!

For those of us who don’t have the unrestricted access having your own Atmos install brings, this experiment was a really useful orientation exercise for me, someone who has attended plenty of Atmos demonstrations but hasn’t perviously had such an opportunity to explore all the stages between familiar old stereo and the super-specified six figure 9.1.6 system you are being dazzled by at a demonstration session. Do Binaural renders sound good? - yes. Can you mix Atmos on headphones - no. Do the consumer options for Atmos playback systems do Atmos mixes justice compared to what the mixer hears? - Surprisingly I’d have to say yes. None of these answers aren’t things I didn’t already believe, but take nobody’s word for it. Now I definitely know.