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The Dolby Atmos Home Theater Paradox

by February 25, 2014
Emmett Brown Paradox Dolby Atmos

Emmett Brown Paradox Dolby Atmos

It's Coming to Home Theater Near You.  Are you Ready?

We’ve heard chatter in the industry that the new surround format Dolby Atmos, originally designed for Cineplexes, may be working its way into new AV receivers as soon as this fall.  For those of you unfamiliar with Atmos, here are some bullet points from their website for a quick overview:

Dolby Atmos:

  • Creates clearer, more accurately positioned cinema sound; uses object-oriented mixing to layer independent sound elements over channel-based audio content
  • Captures all the director’s intent as descriptive metadata to provide customized playback for each theatre
  • Automatically generates optimum soundtracks for theatres with 5.1- and 7.1-channel setups
  •  Delivers a rich, realistic sound experience through support for up to 128 simultaneous and lossless audio elements in a mix
  • Scales easily to any size theatre, with up to 64 independent speaker outputs

Essentially, Dolby Atmos provides more discrete channels, not just for the surrounds, but now for height channels as well, to create a more precise and immersive theatrical experience.  We’ve already heard and written about a few demos of Atmos in action for movies like The Hobbit and Gravity at a local Cineplex.  Our initial impressions were positive, though I felt the height channels were overdone similar to how the surround channels used to be goosed up during the early days of Dolby Digital and DTS.

Dolby Atmos Diagram

Speaker Layout Diagram for Dolby Atmos Theater

We have quite a few questions about how Dolby plans to pull this off. How do they plan on scaling a 64 speaker technology into a 9 or 11 speaker format in a home theater environment?  Are consumers willing to add more speakers, amplifier channels, and cabling to their existing home theaters?  Will consumers have to reposition or replace back channels in favor of height channels? Below we bring even more questions and offer up some answers in hopes of starting a conversation about this to see what people think.

Who Will Adopt this new format?
Discrete 5.1 audio via Dolby Digital and DTS was a big sonic leap forward in producing a realistic surround sound experience in the home when it was introduced back in the 1990’s.  This represented a legitimate reason for people to upgrade their AV receiver.  Until that point we only had two-channel audio matrixed into a simulated 5.1 surround experience via Dolby Prologic Processing.  When lossless discrete 5.1/7.1 surround sound processing was recently introduced to the home market via Dolby TrueHD and DTS HD, it was a huge sonic leap forward for audiophiles that wanted higher fidelity surround sound for music and movies. However the audience that appreciated this higher sound quality was and still is a small minority of the very most passionate audio enthusiasts willing to upgrade their already good sounding Dolby Digital/DTS AV receivers.  The rest of us simply got the upgrade when the technology trickled down to affordable price points they were willing to spend to get the basic switching and processing features of an AV receiver necessary to build a basic home theater system.

Our brains are hardwired to perceive sound in a horizontal plane.  We evolved to evade tigers not pigeons.

What incentive is there for a customer to add more speakers to an already crammed and  budgeted home theater by purchasing a new Dolby Atmos enabled AV receiver?

According to the vast majority of installers and AV manufacturers over 90% of home theaters today are only set up for 5.1.  Why only 5.1?  Limited placement options followed by budgetary concerns are often the two primary reasons.  Not only that, but the market is gravitating more towards soundbars rather than adding more discrete channels.  With people content with MP3 quality audio, one has to wonder just how many enthusiasts will be clamoring for 11 discrete channels of surround  sound.  We are looking at a new format that demands more speakers in a market driven by using less and often smaller speakers.

see:  Dumbing Down of Audio Trading Quality for Convenience

7.1 Speaker Layout

Dolby Recommended 7.1 Home Theater Speaker Layout

Only a small minority of home theater enthusiasts and Audioholics run a full 7.1 system, even fewer currently run height channels for post processing like Dolby Prologic IIz.  This begs the question: Is adding more than seven speakers to a home theater environment more of a novelty than a necessity?  Also, what will the source technology be for transmitting discrete 9.1 or higher audio formats when Blu-ray only supports up to 8 channels?  Are we looking at a new Blu-ray standard to adopt more audio channels or will this be a matrixed solution like most 7.1 Blu-ray recordings are these days anyway?

A New Dolby Atmos Friendly Speaker?

An undisclosed industry source tells us Dolby is asking manufacturers to consider producing a speaker that can sit on top of your main left and right front speakers that will fire up at the ceiling to create the height effect. 

This sounds a bit ridiculous to us for several reasons:

  • Placing a speaker on top of another speaker will compromise the fidelity of both speakers due to acoustical interference.
  • The listener will hear mostly reflected instead of direct sound that will also be very dispersed and not very cohesive.
  • Not everyone has main front left/channels that have flat surfaces large enough to accommodate speaker stacking.
  • And…not a minor consideration….it would look ridiculous.

Our brains are hardwired to perceive sound in a horizontal plane.  We evolved to evade tigers not pigeons. So, adding direct-firing front height and back channels as opposed to coaxial in-ceiling speakers seems to be a more logical choice.  However, how many consumers have high enough ceilings to accommodate additional speakers without having them be too closely placed to the listeners head or near existing speakers for that matter? To that end, how many people have rooms large enough to populate up to 11 speakers without the speakers being right on top of each other causing unwanted interferences?  How much will the height channels need to be turned down to not be more of a distraction than a benefit (i.e. 6dB, 12dB?)

What incentive is there for a customer to add more speakers to an already crammed and  budgeted home theater?

The more practical alternative would be to use in-ceiling speakers as height channels.  But there are issues associated with in-ceiling speakers as well.  Achieving good dispersion from a ceiling-mounted speaker is a problem for anyone but the listener sitting directly under the speaker. Sitting directly under an in-ceiling speaker can be distracting.  Sitting too far off axis can result in poor fidelity and poor timbre matching to the rest of the horizontally firing speakers in your system.  Not to mention, how many people are going to be able to run additional speaker cable through their ceilings to install more speakers?

More is Better?  Maybe NOT!
So now we’ve added 2 or 4 “potentially” poor sounding, poorly positioned speakers to an existing 5 or 7.1 speaker system.  Given the small size of most coaxial in-ceiling speakers, they can also be at a disadvantage dynamically to the rest of the speakers in the system.  Listening to a highly dynamic soundtrack from a movie may reveal great dynamics of a gunshot if fired directly in front, but if a large dynamic peak from a plane flying overhead or an explosion is thrown at the height channels, how realistic will it sound when the speakers are distorting or compressing the effects? To be fair, this is a common problem with the tiny surround speakers used nowadays as well.  

Wall of Speakers

Will the future of surround formats just bring us a wall of speakers?

Most consumer budgets don’t allow for even two high quality speakers in a stereo configuration.  Just how good will their speakers be spreading a two channel budget into 9 or 11 speakers?

Currently there is no physical or streaming format to support more than 8 discrete channels.

The majority of consumers and even installers struggle to properly set up a high performance 5.1 or 7.1 speaker system in a home theater environment that will meet aesthetic appeal.  Can we really expect them to do any better by adding up to 4 more speakers?  What kind of confusion will this cause to a populous that believes audio nirvana is achieved from an iPod dock connected to a cube speaker system or so called “surround soundbar?”

How does this impact the hardware?
About 20 years ago AV receiver manufacturers starting implementing Dolby Digital into receivers.  In order to hit the price points of previous generation receivers they often sacrificed amplifier power supply or other features.  As the trend continued, more features were added as well as more channels.  The roughly same sized power supply of last generation’s 5 channel receiver was now being used to serve 7 channels, followed by 9 channels in more recent Pro Logic IIz receivers.  Basically, manufacturers will now need to adopt a barely adequate power supply designed for 5 channels in their new 9 or 11 channel Atmos receivers.

See: Trading Amplifier Quality for Features in AV Receivers for more information on this topic.

What about a source device?  As previously mentioned, Blu-ray supports up to 8 channels of audio.  Currently there is no physical or streaming format to support more discrete channels.   Does this sound like a familiar story?  Think about 4K or Ultra HD.  We’ve had the higher resolution HDTV technology shoved down our throats, renamed for more appeal and incidentally more confusion, but still have few sources and little content that delivers the “better” promised resolution.

Early Atmos Adopter? Dolby Wants You!

Uncle SamWe are hearing that Dolby Atmos will start working its way into AV receivers starting at around $1k this fall.  Are you ready to jump on the 9.1 or 11.1 surround bandwagon? Or, do you think this will be another forced technology push like 3D and UltraHD have been, from an industry desperate to promote a shiny new product or feature rather than educating the consumers on how to better set up existing technologies to maximize their home theater experience?  It will be interesting to see if consumers will identify a need and benefit for adding more speakers in their existing home theaters and if they will be willing to allocate both budget and space to accommodate. 

While contemplating Dolby Atmos, let’s also not forget that DTS is working on their own competing Multi-Dimensional Audio (MDA) format. 

Are we looking at another format war? Are we being too pessimistic and should support this movement simply in the name of innovation? Share your thoughts in our forum.

Confused about what AV Gear to buy or how to set it up? Join our Exclusive Audioholics E-Book Membership Program!

 

About the author:

Gene manages this organization, establishes relations with manufacturers and keeps Audioholics a well oiled machine. His goal is to educate about home theater and develop more standards in the industry to eliminate consumer confusion clouded by industry snake oil.

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Recent Forum Posts:

RTG posts on October 27, 2019 19:32
Modules really can’t get the job done. I’ve been using them upfiring for a few years. September I decided to mount them on my ceiling in a top middle configuration. It’s night and day. I’ll be adding another pair this Christmas for the top rear for a full 7.2.4 setup.
https://images3.static-bluray.com/htgallery/176922_full.jpg
https://images4.static-bluray.com/htgallery/176923_full.jpg
ellisr63 posts on October 26, 2019 19:38
VonMagnum, post: 1346890, member: 86028
I wasn't aware you had to choose (and I'm not sure what the .3 is on the end; Auro-3D wants front and rear heights or front heights and surround height, although I suppose you could do probably do front heights and top surround, technically speaking).

My home theater supports Auro-3D, Atmos and X (and anything below it) and even 6-speaker matrix stereo for that matter. I use front/rear heights plus I have “top middles” in the Auro-3D “surround height” location (above side surround). I can extract a top middle channel for Auro-3D from between front/rear heights or I can press a speaker select button and move rear height to the surround height location. This also lets me change to 5.1.4 Atmos (tell it I have 5.1 + front/rear height in the assignment menu and rear heights move back to the side surround location with the switch). I can also COPY rear height instead to surround height (like Auro-3D cinemas copy surround height all the way back to rear as well for 11.1 setups). All three formats sound great here, IMO.
The .3 is for 3 subs (it should have been 7.3.6). I do not like Atmos, and want to go to Auro3d…hence 6 overhead channels (3 front heights, 2 surrounds, and the VOG). Base level will be 7 channels.
VonMagnum posts on October 26, 2019 16:56
ellisr63, post: 1346883, member: 17628
I am going to 7.6.3… Atmos sucks, Auro3d is the way I am going to go.

Sent from my SM-T550 using Tapatalk

I wasn't aware you had to choose (and I'm not sure what the .3 is on the end; Auro-3D wants front and rear heights or front heights and surround height, although I suppose you could do probably do front heights and top surround, technically speaking).

My home theater supports Auro-3D, Atmos and X (and anything below it) and even 6-speaker matrix stereo for that matter. I use front/rear heights plus I have “top middles” in the Auro-3D “surround height” location (above side surround). I can extract a top middle channel for Auro-3D from between front/rear heights or I can press a speaker select button and move rear height to the surround height location. This also lets me change to 5.1.4 Atmos (tell it I have 5.1 + front/rear height in the assignment menu and rear heights move back to the side surround location with the switch). I can also COPY rear height instead to surround height (like Auro-3D cinemas copy surround height all the way back to rear as well for 11.1 setups). All three formats sound great here, IMO.
ellisr63 posts on October 26, 2019 16:35
I am going to 7.6.3… Atmos sucks, Auro3d is the way I am going to go.

Sent from my SM-T550 using Tapatalk
VonMagnum posts on October 26, 2019 14:44
Hey, this poll is no good. It only goes to 11.1 speakers. I'm running 17.1 (11.1.6)
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