Now that we are getting more Atmos music releases, I’m interested in how this works with headphones. Having a well set up stereo system, I’m not interested in going with a full speaker set up.
Currently I can listen to 4K movies with Atmos enabled and can get a holistic immersive sound through my Sennheiser HD800’s headphones via ND555/552 to a Heed Canalot headphone amp (with Obselik PS). This is pretty darn good.
My interest now, is trying this with a blurray Atmos music recording, such as Steven Wilsons new The Harmony Codex - which is a specific Atmos recording. So, I’ll buy this and give it a go. Last night I listened to Roger Waters Us and Them in Atmos on the headphones, and that was very good - that probably answers my own question. The HD800’s do have a holistic soundstage, so I’ve a benefit there.
I was reading some threads on the Steven Wilson fan FB group, but responses there were along the lines of using Apple Music and Air Pods as an audiophile system…
Anyway, I thought I raise a topic to share thoughts and experiences on Atmos, particularly in relation to music.
It really comes down to a combination of intent and capability.
ATMOS, like all surround, aims to put you where the action is. Conversely, stereo aims to put the action where you are. So from an intent perspective, stereo seems more suited to music.
Capability is the next issue. Unpacking the ATMOS data, steering it over 2 channels and encoding some phase effects to approximate the effects of ATMOS requires an AV processor. Otherwise it’s just stereo. Getting an ATMOS processor anywhere as good as your stereo preamp is going to be nigh on impossible.
About 25 years ago, Sennheiser had a dedicated headphone amp for Dolby Digital nd DTS called their Teltonic Processor. I can’t rememver what I did with mine. But to work, you had to go through a calibration procedure to adjust for each person’s ear shape and hearing differences. Then it could actually downmix 5.1 surround into stereo with the right phase effects so that you still heard it as surround. I’ve not seen any hifi surround options for headphones since then. Mostly it is one size fits all phase effects built into the headphone output stage of ATMOS enabled AV amps.
Tidal offer 360 Reality Audio and ATMOS streams and Ive never tried them but assumed the only way to hear it is streaming it via my AV Amp to get the surround sound benefit.
All my other devices for streaming Tidal are stereo only so could not see any benefit of trying to play ATMOS or 360 Reality Audio via them unless Im missing something of course?
How does the Uncompressed 2.0 LPCM Stereo audio track sound to the Dolby Atmos audio track through your headphones when listening to Us and Them?
Which one sounds best?
I have many bluray and pure audio bluray music discs with Hi-Res 5.1 and Stereo audio tracks and much prefer the Hi-Res stereo to 5.1 for music.
Well, it’s interesting, as they have different gains. So going from Atmos to LPCM is instantly louder, which is always a bit misleading. I thought the LPCM was more musical, rather than immersive - sort of what @feeling_zen was saying.
That matches my experience too, so for audio discs I always select the hi-res stereo option. I need to do a bit more experimenting with movie soundtracks - from memory most of these only have 5.1 or Atmos etc rather than 2.0 LPCM?
Yes, I should have explained better, for music discs, being audio only, or music concert and video discs, stereo I much prefer to 5.1, I dont like all the concert venue ambient noise coming out of the rear speakers, although some studio albums in 5.1 actually have music out of the rears which is better e.g. Pink Floyd Animals 2018 Remix in 5.1.
However, for movies 5.1 (as thats the maximum my wife allows in the home main lounge - no ATMOS for me) is so much better than stereo as much more immersive and thus it makes you feel you are in the middle of all thats going on on the screen, sort of draws you into the middle of the action so much more than stereo.
Yes, dont normally get stereo tracks on movie discs, but can down mix from 5.1, 7.1 and ATMOS if you only have a stereo speaker set up.
That’s not strictly true. ATMOS isn’t recorded in terms of amplification channels like stereo or even Dolby Digital or DTS. It’s object orientated with each object having a logical channel (64 channels being common in cinemas with 128 catching on). The ATMOS engine then steers the objects according to the 4 dimensional bubble coordinates in the metadata and what is available in your setup. So if you have 5.1 it will steer within that. If you have 9.1.6, it will steer within that. And if you have 2 channel stereo, it will steer within that.
An ATMOS recording then, could encompass just separate logical channels for a guitar, percussion, piano and vocals and then it would use your equipment to steer that amongst amplification channels available even if only two - though you still need a processor. It’s a bit like having the mixing desk work done at your end dynamically. So if your processor supports ATMOS, you can definitely do it with 5.1 speakers. Music ATMOS could in fact still be stereo (it’s basically impossible to determine though without the metadata).
The main difference between domestic and commercial ATMOS is the number of logical channels. Generally Blu-Ray etc, will use 7.1 channels instead of 64 and compromise by the studio having pre-grouped similar object groups as opposed to many discrete objects.
Again, for me, and I say this as someone with a full blown ATMOS setup, the processor and associated DAC and preamp that has is never going to approach what I can afford to do for stereo. My Denon AVR processor is great. But I shudder to think what it would cost to get one up to the same quality as my NDX/282/250. I guess it depends on whether you take the view of Dolby labs or not: they claim their research showed that increased physical and logical channels is far more important to overall fidelity than maxing out the definition of a small number of speakers and amps.
Thanks for the advice on how ATMOS works, Ive always assumed you need the full ATMOS speaker set up to get the benefit of ATMOS.
Its good to know that even on my 5.1 system Im getting some ATMOS benefit, I must say playing ATMOS movie soundtracks does sound pretty good on my system via my Denon AV Amp.
I will now have to try the Them and Us concert in ATMOS to hear how that sounds, never bothered before because I dont have the full ATMOS speaker set up.
Every day is a learning day
I’m still intrigued as to how things work with stereo headphones. Certainly 5.1 or Atmos movies sound great on the HD800 - very immersive, but maybe that’s the just due to the spacial design of the HD800 as I’m running the signal through a stereo system.
Now, another thought - streaming a movie with Atmos through an Apple TV, as that has the spatial audio thing as an affect that would come through on stereo?
Just a stereo setup. So a Cambridge Audio CX UHD 4K player, source either a direct disk, or an HDMI input from a 4K Apple TV. Audio output is coaxial output from the CX UHD direct to the ND555 then 552 to headphone amp. I also have the CX UHD connected to the TV via HDMI (video and audio) and have an optical output from the TV to ND555 - though use the direct coaxial input usually.
Not knowing the Cambridge’s abilities I can’t really know for sure but to the ND555 it will be LPCM over SPDIF. So the question is, is the UHD processing and downmixing ATMOS for you or is it falling back to the non ATMOS stereo LPCM track on the disc?
Yes, I don’t really know. On the screen it says it’s 7.1 Atmos, but that might be the audio signal to the TV via HDMI. What then happens if I use the optical audio out from the TV rather than the coaxial from the UHD. I suppose I should compare them……
I have a Cambridge Audio Azur 752BD Bluray Player ( now in my second system as I upgraded to a Panasonic 4K Player in my main system) and from memory Im pretty sure that for music discs with multiple audio tracks (2.0 or 5.1) you have to manually select which track to play and that is then output from the player either analogue or digital.
However, when playing movies, its normally 5.1 or more and you automatically get 5.1 Dolby Digital out of the digital outputs or you can manually select down mix to stereo, I dont think it automatically switches outputs based on what device the player is connected to, you have to manually choose the output.
So maybe your UHD works the same way as you cant get more than 5.1 DD down the digital coaxial and optical outputs due to bandwidth limitations.
I dont have an Apple TV I have a Samsung but you have to manually set up the optical digital output either Dolby Digital or Stereo PCM.
I just remembered that when I got my Lumin streamer I could see the quality of the digital input signals and for the Panasonic 4K UB-DP9000 Bluray Player output when playing a bluray disc at 24/96 or 24/192 the streamer was only receiving 16/48 from either the coaxial or optical inputs, however the HDMI would give the full 24/96 or 24/192 into either the streamer or my Denon AV Amp.
I queried this with Panasonic Australia who sent it to Panasonic Japan, the reply was that to comply with the content licensing rules for DVD and Bluray the player has to down mix the Hi-Res signal on the discs and has to limit the digital optical and coaxial outputs to 16/48.
Seems like the old rules need to be updated because they can send full Hi-Res over HDMI which seems crazy to me, but thats the rules as they stand at the moment according to Panasonic.
You should check what input signal your ND555 is getting from the UHD coaxial output and also the optical output from the TV as this may also be limited.
I listened to the Dolby Atmos audio track on my 5.1 system tonight and it was very impressive.
The audio track has been mixed for the songs to come mainly through the Front L & R and Centre Channel with not too much out of the Rears and Subwoofer until you get the most impressive animation’s on the screen behind the band and in the centre of the venue at which point the Rears and Subwoofer also really kick in and you get this immersive and impactful sound experience which really enhance the experience of the video imagery.
The concert is fantastic, I had forgotten just how good it is.
50th Anniversary of DSOTM now released on BluRay with Dolby Atmos, Hi-Res 5.1 and Hi-Res Stereo.
Picking my pre-order up on Monday, would be worth a listen.
The Hi-Res Stereo 24/192 has been available on Tidal for sometime in MQA and now Hi-Res FLAC.