• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

An audio engineer explains why Dolby Atmos Music is “definitely going to supersede stereo”

chelgrian

Senior Member
Joined
Jul 27, 2020
Messages
333
Likes
363
A grand piano is no exactly point source. How does Atmos handle that? Can an instrument consist of multiple points? Like putting 3 mics around and into the piano and then call this three close point sources? Same for the drums: one point source for each single percussion instrument?

The simple answer is it doesn't.

You have two options the first is to record with a microphone array which matches the specifications for the location of the bed channels, generally 5.1.4 or 7.1.2 for atmos, and ship a bed only mix. This type of recording is welded to the Atmos speaker layout. For a description of someone doing this see:

https://www.resolutionmag.com/wp-co...n-Lindberg-Resolution-V19.6-Winter-2020-1.pdf

The second is to use an 2nd order ambisonic mic or mic array for example

https://www.core-sound.com/products/octomic

and render from that to the atmos bed channels. The advantage being you can render the original recording to any other layout you wish to in the future.

For studio produced atmos music you might use objects for capturing a performance in a space it would be bed only.
 

Helicopter

Major Contributor
Forum Donor
Joined
Aug 13, 2020
Messages
2,693
Likes
3,944
Location
Michigan
I don't like the idea of Atmos. I'd rather just install speakers in the ceiling if I want sound to come from the ceiling... then you're not depending on such complex geometry and reflection.
 

MakeMineVinyl

Major Contributor
Joined
Jun 5, 2020
Messages
3,558
Likes
5,871
Location
Santa Fe, NM
I can understand the appeal of surround formats for music, but I can't see any benefit for movies as long as they're on a single screen in front. I find the disconnect between the visual and the audio disturbing. If screens wrapped all around, including height, then fine, the sound field and visual field would match, but with current technology of a small screen and wide surround sound doesn't work for me.

So, I don't get what Atmos is trying to do unless they do the same for pictures as for sound.

S
Long before Atmos came out, I wrote a white paper which I distributed to my contacts in film sound about an object oriented sound system idea I had which ended up being very similar to what was to become Atmos - this was around 2000 or so. It had the same object oriented approach which adapted to the particular cinema/home environment, but instead of overhead speakers, it used speakers under the seats in the auditorium which were distributed every 10 feet or so in order that the location of each speaker couldn't be identified as a point source. This in theory brought the sound more 'into the audience', while in conjunction with the normal surrounds, allowed vertical panning of sound effects - think a helicopter landing and taking off in the middle of the auditorium. Or a car which careens off the screen and tumbles around the auditorium.

Obviously Dolby was researching the same thing at the time, unknown to me, but I think what I came up with still had merit.
 
Last edited:

Bear123

Addicted to Fun and Learning
Joined
Nov 27, 2019
Messages
796
Likes
1,370
I don't like the idea of Atmos. I'd rather just install speakers in the ceiling if I want sound to come from the ceiling... then you're not depending on such complex geometry and reflection.
Umm, unless I'm completely missing sarcasm, isn't the whole idea of Atmos to exactly install speakers in the ceiling? Except for the laughable attempts at soundbar Atmos or upfiring atmos speakers, which don't really work very well.
 

Helicopter

Major Contributor
Forum Donor
Joined
Aug 13, 2020
Messages
2,693
Likes
3,944
Location
Michigan
Umm, unless I'm completely missing sarcasm, isn't the whole idea of Atmos to exactly install speakers in the ceiling? Except for the laughable attempts at soundbar Atmos or upfiring atmos speakers, which don't really work very well.
No sarcasm. Many Atmos speakers have Atmos modules with their own channel and input that sit atop floorstanders or bookshelves and fire sound up so that it can bounce off the ceiling and be reflected toward the listener from above. Take a look at Atmos speakers from Focal, Klipsch, Polk, and many others.
 

JoachimStrobel

Addicted to Fun and Learning
Forum Donor
Joined
Jul 27, 2019
Messages
518
Likes
303
Location
Germany
The simple answer is it doesn't.

You have two options the first is to record with a microphone array which matches the specifications for the location of the bed channels, generally 5.1.4 or 7.1.2 for atmos, and ship a bed only mix. This type of recording is welded to the Atmos speaker layout. For a description of someone doing this see:

https://www.resolutionmag.com/wp-co...n-Lindberg-Resolution-V19.6-Winter-2020-1.pdf

The second is to use an 2nd order ambisonic mic or mic array for example

https://www.core-sound.com/products/octomic

and render from that to the atmos bed channels. The advantage being you can render the original recording to any other layout you wish to in the future.

For studio produced atmos music you might use objects for capturing a performance in a space it would be bed only.
So, instruments are no objects but mixed to the bed only, the bed being the Mch layout 5-7.1.2-4? And if I had a 5.1.2 system at home, is there then a translation from 7.1.4 happening? And if I only had a 5.1 system? Or did I misunderstand that?
 

chelgrian

Senior Member
Joined
Jul 27, 2020
Messages
333
Likes
363
So, instruments are no objects but mixed to the bed only, the bed being the Mch layout 5-7.1.2-4? And if I had a 5.1.2 system at home, is there then a translation from 7.1.4 happening? And if I only had a 5.1 system? Or did I misunderstand that?

The normal Dolby downmix rules would come in to play see

https://professionalsupport.dolby.c...d-Stereo-downmix-settings-work?language=en_US

It doesn't mention the height channels I suspect it just ignores them.

From what I can find Dolby seem to recommend delivering beds in 5.1.4 rather that 7.1.2. That means it never needs to do problematic mixing of the rear channels which can result in comb filtering.

In reality most film is delivered with a separate stereo and atmos track as the atmos down mixing doesn't work well enough.

Yet another reason ambisonics is better there is no down mix you just render the sound field to the two stereo speakers and it just works.
 

Frank Dernie

Master Contributor
Forum Donor
Joined
Mar 24, 2016
Messages
6,445
Likes
15,780
Location
Oxfordshire
Most of the people I know consider the cost and mess associated with more than 2 speakers to be an unacceptable sacrifice to make for a not-big-enough improvement, So despite its evident benefits multi channel will remain a minority interest for music IMO, and a small minority at that.
 

bluefuzz

Major Contributor
Joined
Jan 17, 2020
Messages
1,043
Likes
1,772
I can understand the appeal of surround formats for music, but I can't see any benefit for movies as long as they're on a single screen in front. I find the disconnect between the visual and the audio disturbing.
This! I too find 3D movie effects simply annoying and distracting. The action is on a screen in front of me, so why should the sounds come from behind or above me? Its just effects for the sake of effects.

There is an artistic argument for music with greater spatial effects than simple stereo but the chances of it catching on with the general public are minimal to say the least. Stereo has been the norm for ~70 years and the vast majority of people still can't be bothered to set their speakers (if they have them) up to get the best stereo image. Speakers are most often just jammed into the nearest available shelf or more likely sit on the floor where convenient. The number of times I've seen two stereo bookshelf speakers on top of each other in a corner is telling. People simply don't have the space or the inclination, let alone the budget, for multiple speakers in their living space.
 

Bear123

Addicted to Fun and Learning
Joined
Nov 27, 2019
Messages
796
Likes
1,370
This! I too find 3D movie effects simply annoying and distracting. The action is on a screen in front of me, so why should the sounds come from behind or above me? Its just effects for the sake of effects.

I'm not sure this makes sense. Just like in real life, we can hear things we aren't looking at. We can hear behind us and beside us even if not looking in that direction. A good sound track adds a lot of immersion with surround.....when something happens off to the side or behind, surround places the sound there, which creates a more realistic and immersive effect. I would argue just the opposite......if a sound is supposed to come from the side or rear but instead only has 2 channels directly in front of you to play through, its as antiquated as watching a movie on a black and white TV. Not to mention if you don't sit directly in the center. Even so, I wouldn't downgrade by eliminating my center channel.

If I had a music only system, I would probably stick to 2.2. But since I have a combined system for both tv/movies and music, its really easy and doesn't cost any extra in terms of equipment/speakers etc. If I was music only, not sure I'd be willing to add 3/5/7 more speakers.

I can see both sides. I do think there are a lot of people that use their system for both purposes.

I actually do switch back and forth from 2 channel(2.2) to 5.2, and more often than not, I find 5.2 better, even for music.
 
Last edited:

maverickronin

Major Contributor
Forum Donor
Joined
Jul 19, 2018
Messages
2,527
Likes
3,308
Location
Midwest, USA
I definitely understand the appeal of surround formats, but atmos isn't going to make any headway outside of Hollywood. A expensive, closed format like that is not is not going to get any traction.

5.1 and 7.1 are open, highly supported formats and outside of classical there is essentially zero straight musical content in those formats. How is atoms going to do any better?

Surround formats are certainly better than stereo, but the main issue is inertia. We're coming up on 100 years of content recorded in stereo. 99+% of new music continues to be mixed in stereo. Very few people are going to go to the expense of a music-quality 5/7.1 surround system, much less atmos, for the trickle of new releases in those formats.

If any of these formats want to take off, what they actually need is a good upmixer. Producers will actually have a customer base to sell new content to because consumers can more easily be sold on an expensive system if it isn't devoid of benefit for 99% of existing content.

Perhaps ironically for Dolby, word on the street is that Auro actually has the best upmixer.

I don't actually know for myself though, since those kind of things only exist in AVRs and pre-pros, and as far as I can every last one of them is a dumpster fire full of burning black boxes.
 

Bear123

Addicted to Fun and Learning
Joined
Nov 27, 2019
Messages
796
Likes
1,370
No sarcasm. Many Atmos speakers have Atmos modules with their own channel and input that sit atop floorstanders or bookshelves and fire sound up so that it can bounce off the ceiling and be reflected toward the listener from above. Take a look at Atmos speakers from Focal, Klipsch, Polk, and many others.
I guess I didn't make it clear enough that your statement didn't make sense to me. You said: "I don't like the idea of Atmos. I'd rather just install speakers in the ceiling if I want sound to come from the ceiling.." Well, that IS the idea of Atmos. Poor implementation with upfiring modules is what doesn't make sense to you. And I agree with you, not from personal experience, but from what I've heard from everyone who has actually tried real Atmos(ceiling speakers) vs upfiring. It's kind of like surround sound with a sound bar. Its not the surround sound thats bad, but the implementation that just doesn't actually work very well, if at all.
 

sergeauckland

Major Contributor
Forum Donor
Joined
Mar 16, 2016
Messages
3,440
Likes
9,100
Location
Suffolk UK
I definitely understand the appeal of surround formats, but atmos isn't going to make any headway outside of Hollywood. A expensive, closed format like that is not is not going to get any traction.

5.1 and 7.1 are open, highly supported formats and outside of classical there is essentially zero straight musical content in those formats. How is atoms going to do any better?

Surround formats are certainly better than stereo, but the main issue is inertia. We're coming up on 100 years of content recorded in stereo. 99+% of new music continues to be mixed in stereo. Very few people are going to go to the expense of a music-quality 5/7.1 surround system, much less atmos, for the trickle of new releases in those formats.

If any of these formats want to take off, what they actually need is a good upmixer. Producers will actually have a customer base to sell new content to because consumers can more easily be sold on an expensive system if it isn't devoid of benefit for 99% of existing content.

Perhaps ironically for Dolby, word on the street is that Auro actually has the best upmixer.

I don't actually know for myself though, since those kind of things only exist in AVRs and pre-pros, and as far as I can every last one of them is a dumpster fire full of burning black boxes.

What gets me is the dichotomy between someone who claims that Atmos, with 7+ loudspeakers (or not!) is the next best thing when most people I know listen on Amazon Echoes or Bluetooth 'singing bricks' in mono. The number of 'proper' stereos seen in peoples' homes these days are vanishingly small, and of those, how many actually have the loudspeakers properly sited? What proportion of the General Public have a proper Home-Cinema system as opposed to a sound-bar?

Quadraphonics failed in the 1970s, mostly because of the three competing and incompatible systems, but in large part because it was hard enough to position stereo 'speakers correctly, let alone four. With homes becoming smaller, (certainly this side of the Atlantic), except possibly for sound-bars, any form of surround sound will not become mass-market. In any case, listening to music as a dedicated activity as opposed to having it on in background, has ceased to be a mainstream activity, even computer games gets more time devoted than music listening.

S.
 

sal

Active Member
Forum Donor
Joined
Mar 23, 2021
Messages
126
Likes
169
The question I have is: how much does the music need to be compressed to transmit all these channels? Even over HDMI, there's likely to be some compression, and how many hifi systems have HDMI these days. IMO, that is one of the big downfall of the n.1 systems. I don't want to invest in a home theatre system to listen to compressed music.
 

MakeMineVinyl

Major Contributor
Joined
Jun 5, 2020
Messages
3,558
Likes
5,871
Location
Santa Fe, NM
What gets me is the dichotomy between someone who claims that Atmos, with 7+ loudspeakers (or not!) is the next best thing when most people I know listen on Amazon Echoes or Bluetooth 'singing bricks' in mono. The number of 'proper' stereos seen in peoples' homes these days are vanishingly small, and of those, how many actually have the loudspeakers properly sited? What proportion of the General Public have a proper Home-Cinema system as opposed to a sound-bar?

Quadraphonics failed in the 1970s, mostly because of the three competing and incompatible systems, but in large part because it was hard enough to position stereo 'speakers correctly, let alone four. With homes becoming smaller, (certainly this side of the Atlantic), except possibly for sound-bars, any form of surround sound will not become mass-market. In any case, listening to music as a dedicated activity as opposed to having it on in background, has ceased to be a mainstream activity, even computer games gets more time devoted than music listening.

S.
If Atmos as a music format makes any headway, it will be in homes which already have a home theater; everything to listen is already in place although the many systems which consist of only a sound bar will not get a lot of the benefit. However, there are plenty of people who are installing home theater systems which use either a good AVR or home theater preamp with multi-channel power amplifier (if all the pre/pros and multi-channel power amps I see flying off our assembly lines are any indication).

What does not compute is the fantasy that regular home stereo listeners are going to radically change their listening environments and gear just to listen to what limited selection of Atmos music selections there are. If they are changing to a complete home theater system in order to watch movies too, then great - that makes sense. But for music only listeners (the few that are serious listeners who don't have music only as a background), this problem has already been solved, and an enveloping sound stage is only as far away as proper placement of the speakers and a room which has been optimized acoustically. If neither of these things are accomplished, then throwing more technology such as Atmos, sure isn't going to help things.
 

tomelex

Addicted to Fun and Learning
Forum Donor
Joined
Feb 29, 2016
Messages
990
Likes
572
Location
So called Midwest, USA
Of course. But switching from stereo to mono produces another kind of weird effect. So which one is the right kind of experience?


Neither one is right for 21st century. We need something new. Or even to perfect something that pre-dated stereo, that's binaural, at least for headphone listening.
 

mhardy6647

Grand Contributor
Joined
Dec 12, 2019
Messages
11,216
Likes
24,177
Besides competing formats and marginal enhancement in 'bottom line' audio performance or quality, the failure of quad was abetted by the truly lousy economy (at least in the US) of the early/mid 1970s. I remember eating a lot of chicken and hot dogs in those days...

1616952087555.png


Then my slice of the boomer generation reached college age and we all went nutso buying (mostly Japanese) hifi, revitalizing the market for at least a few years.

and, of course, even the dark days of inflation and energy crises (i.e., the mid-late 1970s) had its visionaries...

 

andymok

Addicted to Fun and Learning
Joined
Sep 14, 2018
Messages
562
Likes
553
Location
Hong Kong
The whole point of the discussion here is, from artistic and economic pov, consumer gets to choose what they want, stereo, surround, ambisonics whatever; musicians and composers can write, create and reproduce whatever they want, like the off-stage brass choir in Berlioz's Requiem, our rendition of Eric Whitacre's work among audience, and engineers only need to capture, mix once and deliver to all, from earbuds, theatre to concerts and installations
 

chelgrian

Senior Member
Joined
Jul 27, 2020
Messages
333
Likes
363
The question I have is: how much does the music need to be compressed to transmit all these channels? Even over HDMI, there's likely to be some compression, and how many hifi systems have HDMI these days. IMO, that is one of the big downfall of the n.1 systems. I don't want to invest in a home theatre system to listen to compressed music.

The TrueHD version of Atmos is losslessly compressed. The problem is that it's only used for UHD Blu-ray. Bear in mind that you can get uncompressed 7.1 LPCM across HDMI so the 50% or so compression you can get out of a lossless algorithm is enough.

However the primary delivery mechanism for Atmos is Dolby Digital Plus this is what you'll get when streaming movies and what you'll get out of Tidal and Amazon. DD+ is a lossy perceptual codec with a data rate of 6144 kbit/s with joint encoding which takes advantage of some of the redundancy between the channels.

When you deliver Atmos music to the services it's delivered as a broadcast WAV file with all the original objects (if used) and metadata intact via a service like Avid Play. So they at least have the full quality available which could be delivered in a better distribution format in the future.
 

chelgrian

Senior Member
Joined
Jul 27, 2020
Messages
333
Likes
363
The whole point of the discussion here is, from artistic and economic pov, consumer gets to choose what they want, stereo, surround, ambisonics whatever; musicians and composers can write, create and reproduce whatever they want, like the off-stage brass choir in Berlioz's Requiem, our rendition of Eric Whitacre's work among audience, and engineers only need to capture, mix once and deliver to all, from earbuds, theatre to concerts and installations

Except the consumer doesn't get to choose because there is no useful way to distribute an ambisonic mix, no standard to get it across HDMI and there zero AVRs that can render it.

Dolby would do all they could to prevent such a thing happening as would entirely undermine their Atmos licensing revenue.
 
Top Bottom