or Connect
AVS › AVS Forum › Display Devices › Ultra Hi-End HT Gear ($20,000+) › D-cinema Equipment and Theaters › Dolby Atmos Theatre System
New Posts  All Forums:Forum Nav:

Dolby Atmos Theatre System - Page 24

post #691 of 918
Quote:
Originally Posted by thebland View Post

Curious... do these theaters use full range surrounds or cross over to higher frequencies?
I think Atmos marks the first time bass management has been used in commercial cinema. I've been to 5 of the 8 Atmos cinemas around the Los Angeles area, and they ALL have subs mounted high up at the back of the auditorium.

From the Dolby Atmos Specifications paper:

"If bass management is used, the surround loudspeakers frequency response (±3 dB) must extend to 90 Hz or lower. The crossover frequency should be set based on the capabilities of the surround loudspeakers, but must not be higher than 100 Hz."
Quote:
Originally Posted by thebland View Post

I had a conversation with an expert recently and he seemed to prefer a surround that could play to lower frequencies but I didn't get the 'why'...
Because crossovers aren't brick walls, so if you cross over at 80Hz, then it is helpful to have your speakers go one octave lower (40Hz).
post #692 of 918
Quote:
Originally Posted by mtbdudex View Post

Film mixer, do the specs for Atmos specify mixing discrete down to how low?
40hz, 60hz, or there is no spec and left up to each production?


Via my 64GB iPhone 5s using Tapatalk

They don't specify what is in the content, only what they need the playback systems to spec out at.

As sanjay pointed out, most theaters are using subs for the auditorium speakers bass management.

The stage I am currently mixing on recently added Atmos into the room... they added two dual x 18 surrounds in the ceiling (one over the console, one further back over the client area.)
post #693 of 918
Filmmixer,

What are the theoretical advantages of full range surrounds vs those crossed at 80-100 Hz? (If any)

Thanks!smile.gif
post #694 of 918
Quote:
Originally Posted by thebland View Post

Filmmixer,

What are the theoretical advantages of full range surrounds vs those crossed at 80-100 Hz? (If any)

Thanks!smile.gif

There's nothing theoretical about it. .

They sound better.

In practice sound travels off the screen seamlessly into the auditorium, as was witnessed in Gravity.

With ATMOS you have the option of treating the surrounds as arrays as in a traditional 7.1 setup or as point sources.

It is one of the reasons I prefer this approach over what Barco has offered. They only employ stereo surrounds, with no back wall option, although now with an added height array (and the overhead is still only mono using an array of speakers.).

This might change with Auro + MDA.
post #695 of 918
Quote:
Originally Posted by FilmMixer View Post

There's nothing theoretical about it. .

They sound better.

In practice sound travels off the screen seamlessly into the auditorium, as was witnessed in Gravity.

With ATMOS you have the option of treating the surrounds as arrays as in a traditional 7.1 setup or as point sources.

It is one of the reasons I prefer this approach over what Barco has offered. They only employ stereo surrounds, with no back wall option, although now with an added height array (and the overhead is still only mono using an array of speakers.).

This might change with Auro + MDA.

Thanks!

When will we see soundtracks with 9, 11 or more channels on Blu ray?


Also any experience or thoughts on Trinnov processing?

Thanks!
Edited by thebland - 11/17/13 at 4:11pm
post #696 of 918
Quote:
Originally Posted by FilmMixer View Post

Because there might be information in the audio you don't want, can't hear, etc.

The discussion keeps coming up using descriptors like "neuter" and "compromise."

There is no grand conspiracy to change the artistic intent that the director and sound crew worked for months to create.

There are no theaters that can reproduce <18Hz content with any consistency.

We have a spec, and an industry accepted tuning.

If a mixer feels that they will gain headroom in the LFE channel for audible material, they may choose to introduce a slight roll off to the content being fed to that channel.

Again, we don't have these "neutering" brick wall filters on our consoles.

And again, the use of the word "filtered" is incorrect in 99% of the discussions the LFE discussions.

In most ceases, the material wasn't there from the start... a number of sound designers I've talked to confirm this.

These are my opinions, and obviously there are others in the business that spend the effort and time creating ULF content, either by design or by accident.... I can tell you, however, I've never been in a sound designers room, or a mixing stage, where someone is constantly analyzing the frequency content of what is being sent to the LFE channel.

I personally am not overly concerned with creating material under 20Hz, because very few can reproduce it accurately.

I also don't want to discount the desire of those seeking to do so., and I personally don't HPF my LFE (but I do LPF it at 80Hz.)

Preference, choice and taste... those are three "why's" to your question.

(as a side note, Marti might chime in on how his mix for Oz translated from a larger servo driven sub system in a big dub stage to his very powerful multi sub Meyer system (which is designed not only for even response over a large portion of his room, but also copious extension, output and head room.)
Thanks for your insight into this, much appreciated!
post #697 of 918
I agree with filmixer but the Dolby Atmos system can be considerably enhanced by better sound reproduction chain and additional dsp to the behind the screen channels to remove the annoying micro perf bug.

I am writing about that on a DCI forum elsewhere .

Something amazing has just happened. Due to Dolby Atmos I am completely refocusing my mission in life and thus I will continue my exploits in a DCI oriented venue.

I invite my friends to read more about the quested final calibration and how we licked the screen bug and other crazy **** at HERE
post #698 of 918
Thread Starter 
Quote:
Originally Posted by CINERAMAX View Post

I invite my friends to read more about the quested final calibration and how we licked the screen bug and other crazy **** at HERE
I read the post, but saw nothing about calibration or fixing the screen bug. Are there more than 6 paragraphs? Maybe I have to become a member to see the whole post?
post #699 of 918

Edited by CINERAMAX - 11/17/13 at 7:27pm
post #700 of 918
Quote:
Originally Posted by FilmMixer View Post

I don't think the term "upmix" is correct when talking about object based solutions...

...Depending on what platform you are using (i.e. Neve Console vs. Pro Tools "in the box" for example) there may be benefits to starting in 7.1 and completing the Atmos and/or Auro mixes after the fact.

I guess I'm still not getting some basic concepts.

I thought if something was 7.1, then it's channel-based, not object-based, so how could you get height channels where before there were none, w/o upmixing?
Quote:
Originally Posted by thebland View Post

I am wondering what the benefit is to surrounds that can play down to 40-50 Hz versus those that can only play down to 80-100 Hz as I am looking at new surrounds myself and am debating the advantage of one that plays lower.

A disadvantage of surrounds playing lower is decreasing determinacy of bass response smoothness because different bass sources at different times will change how they sum.
Quote:
Originally Posted by sdurani View Post

I think Atmos marks the first time bass management has been used in commercial cinema.

Really? They're run full range?
post #701 of 918
Quote:
Originally Posted by noah katz View Post

I thought if something was 7.1, then it's channel-based, not object-based, so how could you get height channels where before there were none, w/o upmixing?
Because all the individual pieces of sound are not married together yet. During the mixing phase, those individual pieces of sound just behave like a 7.1 mix (they're tagged with info on channel, level, equalization, etc). Which is what allows for changes in the mix. During this phase, the mixer can grab individual pieces of sound (objects) and place them on the Atmos bus to be moved around in a way that can't be done with channel-based mixing.
Quote:
Originally Posted by noah katz View Post

Really? They're run full range?
Yup, closest they got is the option to copy the bass from the L/C/R channels to the subs, but couldn't high-pass those channels for the speakers (which typically rolled off at 40-50 Hz). Atmos does bass management for the surrounds, which is why the local Atmos theatres I've been to have added new subwoofers at the back of the room.

http://www.hometheaterhifi.com/volume_7_2/feature-article-misunderstood-lfe-channel-april-2000.html
post #702 of 918

when do you think we will see ATMOS in receivers?

post #703 of 918
Quote:
Originally Posted by wse View Post

when do you think we will see ATMOS in receivers?


Interesting, I've gone 11.3, have NeoX in my Denon 4520CI...so I'm curious thinking here also.

I guess at most there will be say 11 channel via AVR, then some digital buss to outboard processor for the additional ceiling/other speakers, and from that amp for those also.
That would put the added cost burden to outboard components, yet via digital buss the AVR would be master and control slave outboard units.

Each HT could then manage their added discrete units as their room size and layout allowed.


Via my iPhone 5s using Tapatalk
post #704 of 918
Quote:
Originally Posted by sdurani View Post

Because all the individual pieces of sound are not married together yet. During the mixing phase, those individual pieces of sound just behave like a 7.1 mix (they're tagged with info on channel, level, equalization, etc). Which is what allows for changes in the mix. During this phase, the mixer can grab individual pieces of sound (objects) and place them on the Atmos bus to be moved around in a way that can't be done with channel-based mixing.l

So it's like they're imprinted with 7.1 genes that haven't been expressed yet, and they can be taken back.

Still don't get running theater surrounds full range; it just make senses to HP any speaker or driver above freq where it cannot produce meaningful output.

Thanks
post #705 of 918
Quote:
Originally Posted by noah katz View Post

So it's like they're imprinted with 7.1 genes that haven't been expressed yet, and they can be taken back.

Still don't get running theater surrounds full range; it just make senses to HP any speaker or driver above freq where it cannot produce meaningful output.

Thanks

Noah. Sorry it's taken time to reply.

Regarding full range surrounds. They can be full range to spec or bass managed.

I have yet to see an ATMOS install without bass management, even in stages with the new JBL surrounds that use 12" LF drivers.

You first question a couple of posts back needs some clarification.

My original conversation and comments were in regards to how the different types of work flow ( ie mixing in 7.1 first or ATMOS ) isn't a meaningful barometer of how effective the ATMOS mix will be.

For clarification let me explain a bit about how ATMOS works.

It is actually a channel and object based system.

You now have a 9.1 channel based bed. In addition to the standard 7.1 you add two arrays of overhead speakers. In addition they have added back two additional behind the screen channels left and right extra... They are not implemented into the bed.

For clarity the bed 9.1 utilizes arrays for the surround zones and overheads, just like a traditional theatrical 7.1 setup.

In addition to the bed, you have an additional 118 discrete objects. The objects can be the size of one speaker or spread out (what is referred to object size.).

When playing back the mix, the rendering unit pans the objects in real time using as many speakers as present in the playback system.

In this way the systems are scalable to the room size and equipment present.
Edited by FilmMixer - 11/20/13 at 9:55am
post #706 of 918
Quote:
Originally Posted by noah katz View Post

So it's like they're imprinted with 7.1 genes that haven't been expressed yet, and they can be taken back.
Yup, as Dr. Evil would say, "I shall call this imprinted information metadata".
post #707 of 918
any news on dolby atmos' expansion into more theaters? I've checked showtimes for upcoming movies at my local theater, no atmos mentioned.
post #708 of 918

Really 11 speakers is the max unless one uses in wall, or Orb audio spheres :)

post #709 of 918
I just watched the new Hunger Games movie in atmos. Really wasn't impressed. There is one scene with loads of birds, really expected atmos to shine there. Unfortunately it never did. Having watched Iron Man 3 and now Hunger Games I just don't think it's really worth watching a movie in atmos. The most exciting part is the demo before the movie starts.
post #710 of 918
Quote:
Originally Posted by Roger Dressler View Post


While I have stated in the past that IMM is object based, I have recently learned that the rendering is Ambisonics based (not sure if it high order or not). In one sense that is the beauty of object-based content delivery: it can be rendered with conventional panning (the 3D version being called VBAP, or vector base amplitude panning), or WFS as in IOSONO, or Ambisonics (or HOA), all from a single soundtrack.

 

Hi, just to clarify for those interested, Dolby Atmos is not based on Ambisonics per se.

 

Ambisonics actually defines a way to encode an omni-spherical acoustic sound field and typically requires the use of a sound field microphone array ( all least 5 calibrated mics) to properly capture and encode the omni-spherical sound pressure (W), and the three components of the pressure gradient (XY, and Z) into 4 discrete audio tracks. The encoding theory for Ambisonics was invented well over 30 year by Michael Gerzon of the Mathematical Institute, Oxford, who with Professor Peter Fellgett of the University of Reading, David Brown, John Wright and John Hayes of the now defunct IMF Electronics, and building on the work of other researchers, developed the theoretical and practical aspects of the system in the early 1970s. 

 

But while Ambisonic-encoded sound tracks can be used to reproduce the original sound field for rendering and playback over any surround sound format independent of speaker placement, in contrast the Dolby Atmos system is a sound-object-based decoding and playback rendering system, where the discrete sounds contained in a film sound track are actually encoded as discrete sound objects that precisely define when, where and how in the surround sound field each discrete sound is to be played back in real-time. Since each sound object contains all information necessary to direct and playback the desired sound in the desired sound field, the Dolby Atmos System takes this sound placement information, and in combination with its knowledge of the discrete physical placement of all the speakers in the room, renders this information so that the encoded sound object is decoded for appropriate real-time playback over the desired speakers to faithfully recreate the film's intended surround sound field. While the technical process to do this is extremely compute intensive, thanks to the power of today's digital signal processors (DSPs), this is now beautifully achievable.

 

For more information on how sound objects work, and for an example of some of the tools that are used in today's post production to create such sound object-encoded sound tracks, check out http://www.auro-technologies.com 

 

It's pretty cool stuff.

 

Hope the above was helpful!

 

FOHMixMeister

post #711 of 918
Quote:
Originally Posted by FOHMixMeister View Post

in contrast the Dolby Atmos system is a sound-object-based decoding and playback rendering system...

Dolby Atmos is both a channel and object based system.

The first 10 tracks of the Atmos recording form the 9.1 channel bed, the other 118 tracks are available for objects.
post #712 of 918
Quote:
Originally Posted by amairphoto View Post

I just watched the new Hunger Games movie in atmos. Really wasn't impressed. There is one scene with loads of birds, really expected atmos to shine there. Unfortunately it never did. Having watched Iron Man 3 and now Hunger Games I just don't think it's really worth watching a movie in atmos. The most exciting part is the demo before the movie starts.

It's still new! Give the mixers time to get used to it (like 7.1 when it started!) I actually found the Iron Man 3 and Thor 2 mix to be underwhelming
post #713 of 918
Quote:
Originally Posted by FOHMixMeister View Post

Ambisonics actually defines a way to encode an omni-spherical acoustic sound field and typically requires the use of a sound field microphone array ( all least 5 calibrated mics) to properly capture and encode the omni-spherical sound pressure (W), and the three components of the pressure gradient (XY, and Z) into 4 discrete audio tracks.

Interesting, I thought Trinnov was the first to use a mic array to capture 3D info.

...in combination with its knowledge of the discrete physical placement of all the speakers in the room...[/quote]

Do you know if the speaker placement knowledge is entered manually or calculated by the s/w?

Thanks for your post.
post #714 of 918
Thread Starter 
Quote:
Originally Posted by noah katz View Post

Interesting, I thought Trinnov was the first to use a mic array to capture 3D info.
Trinnov only captures sound, as you well stated, to gain >>knowledge of the discrete physical placement of all the speakers in the room.<< It is not a sound format like Atmos, Ambisonics, etc. FOHMM is referring to the mics used to record sound in Ambisonics format.
Quote:
Do you know if the speaker placement knowledge is entered manually or calculated by the s/w?
For cinemas, thus far all the formats use manual entry. That could change. It's a secondary function of the sound system -- calibration.
post #715 of 918
Quote:
Originally Posted by FilmMixer View Post

Dolby Atmos is both a channel and object based system.

The first 10 tracks of the Atmos recording form the 9.1 channel bed, the other 118 tracks are available for objects.

Marc,

How do you guys handle reverberation for objects?
post #716 of 918
Quote:
Originally Posted by FilmMixer View Post

Dolby Atmos is both a channel and object based system.

The first 10 tracks of the Atmos recording form the 9.1 channel bed, the other 118 tracks are available for objects.
So, if 9.1 is in the channel bed it should be easy for 9.1 to be put on blue ray discs or am I reading this wrong.
post #717 of 918
Thread Starter 
Quote:
Originally Posted by 99rook99 View Post

So, if 9.1 is in the channel bed it should be easy for 9.1 to be put on blue ray discs or am I reading this wrong.
I don't see the relevance of 9.1, but technically, the current HD codecs used in BD can carry channels/objects of various configurations, should that be necessary.
post #718 of 918
Quote:
Originally Posted by FilmMixer View Post

Dolby Atmos is both a channel and object based system.

The first 10 tracks of the Atmos recording form the 9.1 channel bed, the other 118 tracks are available for objects.

And you can hear that in Gravity. You have a solid 3d soundfield as a base layer and then you have these panning, orbiting folleys.

In the trinnov system in Moscow once the overhead speakers were placed, listening to the destruction scene of the Ironman 's pad it is a completely holosonic 3d sound field much like that atmos base.

What was missing where the cool sounding pans, orbits(the houston houston) and punch troughs (a series of sounds that sweep from front to back at low altitude that appear to punch through you-ie space debris hitting space station on ).

But absent that, the "Atmos base" can be recreated very well with the ada trinnov.


Edited by CINERAMAX - 11/29/13 at 7:05am
post #719 of 918
Quote:
Originally Posted by Roger Dressler View Post

I don't see the relevance of 9.1, but technically, the current HD codecs used in BD can carry channels/objects of various configurations, should that be necessary.

Except that the bed will be missing all of the object audio, so it's not a usable track for authoring to answer the OP question.
post #720 of 918
Quote:
Originally Posted by markus767 View Post

Marc,

How do you guys handle reverberation for objects?

It depends on what the object would be doing.

There is no one answer I can give because every piece of audio might be treated differently.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: D-cinema Equipment and Theaters
AVS › AVS Forum › Display Devices › Ultra Hi-End HT Gear ($20,000+) › D-cinema Equipment and Theaters › Dolby Atmos Theatre System