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The official Dolby Atmos thread (home theater version) – Check out post 1 first

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#1 · (Edited)
Last update: 02.04.2023



Official Dolby Atmos at home website

Dolby on Atmos for the home
Dolby Atmos Speaker Setup
Ceiling-firing speakers ("Atmos-enabled speakers")
http://www.dolby.com/us/en/technologies/dolby-atmos/dolby-atmos-enabled-speaker-technology.pdf
Speaker installation guidelines
http://www.dolby.com/us/en/technolo...tmos-home-theater-installation-guidelines.pdf
If you're more the visual type of guy here's a good video explaining the basics of placing your Atmos speakers:

Insights from a recording and mixing engineer


Technical specification for studios wishing to employ a 7.1.4 home entertainment Dolby Atmos monitoring setup
Dolby Atmos Home Entertainment Studio
Certification Guide


Blog posts
Dolby Atmos: Coming soon to a living room near you - Lab Notes
Dolby Atmos for home theaters: FAQ - Lab Notes


Dolby Patent Application
http://www.freepatentsonline.com/WO2014036085A1.html


Dolby on Atmos for movie theaters
Wayback Machine

Specifications for movie theaters
Wayback Machine


How Atmos content is created
Wayback Machine


How Atmos is encoded into TrueHD and Dolby Digital Plus
https://professional.dolby.com/site...on/dolby-atmos/dolby_atmos_renderer_guide.pdf


avsforum.com Members Atmos & Auro Configuration Spreadsheet (at Google Docs, maintained by user kokishin)


Atmos test tone downloads (E-AC-3 audio in .mp4 container)
https://www.dolby.com/us/en/guide/test-tones.html

Other Dolby trailer downloads
 
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#4,421 · (Edited)
The current question:


Is the Atmos speaker filtering built into the Atmos speaker or is the filtering part of the Atmos AVR's DSP?




Psychoacoustics and the development of Atmos speakers and modules.

Staying with speakers for a moment, JJ also gave us some insight into how Dolby had developed the concept of upwards firing speakers and a hint of the incredibly sophisticated technology which lies behind the way they work so well.

Dolby spent some considerable time (and no doubt money) researching the way our ear/brain combination works with regard to our perception of overhead sounds. Apparently, when we hear sounds from overhead, there is a natural 'notch filter' engaged by our brain and the physical disposition of our ears (and even our shoulders which reflect sound back up to our ears) and between them, these help us determine when sounds are emanating from overhead. To capitalise on this, Dolby's Atmos speakers and modules have a frequency response which is shaped by internal DSP in the AVR. This includes a recreation of that notch filter which is important in telling us that a sound is coming from above us. At this time, Dolby would not reveal at what frequency this notch filter operates other than that it is in the HF area. I speculated 7kHz and JJ said “no, it will be much higher than that”. No doubt someone with suitable measuring equipment and a white noise generator will be able to determine the precise frequency at which the filter operates, once Atmos units are available to buy.



and




This Atmos-enabled speaker (maker unknown) includes a small upfiring driver that sends the overhead signal to the ceiling, which reflects it down to the listeners. (Photo by Mark Henninger)

But there's more to it than simply adding some transducers to the top of a speaker—the system must replicate the effect of a human head as sounds from above, especially high frequencies, bend around it. This height-cue filtering is performed using standard analog components built into each Atmos-enabled speaker.



Source information below:


http://www.avsforum.com/forum/286-latest-industry-news/1646937-dolby-demos-atmos-cinema-home.html#post26623145




Some new information on the issue below here:




I was chatting with Brett before the demo began and got different information about the two items below: I was told it was done in the AV receiver, which is why you have to tell it whether you're using ceiling-mounted OR upward-firing speakers, so it knows whether to turn on Dolby Elevation processing. I was told that Dolby Surround upmixes all incoming sources to up to 24+10 speakers, including wides, and that it has a centre width adjustment (like PLII currently has for 2-channel sources).

Will have to get clarification on both points.



and response from Scott




Sanjay, these were both points that Dolby made during the fact check of the article. I had originally written that the height DSP was done in the AVR, which is what I understood from the discussion, but they "corrected" that to what ended up in the article. Also, I recall you saying in our after-event discussion that the wides were not used in an Atmos upmix, which Dolby confirmed in the fact check.



and




Bizarre that it is done in the analogue domain. First I've heard of it. I mentioned the lack of wides as an example of the gulf between capability vs implementation. Atmos is capable of rendering to actual speaker locations even though none of the manufacturers have implemented it that way. Dolby Surround is capable of upmixing to all 24 speakers on the floor, even though current implementation doesn't include wides.

Apparently that last part (not using wides) is how the upmixer is supposed to operate, not a limitation of current implementation. Like I said, it conflicts with what Brett told me. Then again, we were told DS had a music mode, only to get an e-mail later clarifying that there is no such thing.
 
#4,424 ·
Well I wish I knew about this I would have held off on the x4000 6 months ago and just waited for Atmos.

I have a pretty small room, but it's got a low ceiling and thick carpeting so it's pretty good for audio. I take it my options are. . Having 5.2 already.

-New receiver required
-addition of 4 small ceiling speakers to current set up
-replacement of Front LR and SL/SR to speakers that also fire upwards at an angle (IE: Atmos speakers)

Is this true?
 
#4,425 ·
Well I wish I knew about this I would have held off on the x4000 6 months ago and just waited for Atmos.

I have a pretty small room, but it's got a low ceiling and thick carpeting so it's pretty good for audio. I take it my options are. . Having 5.2 already.

-New receiver required
-addition of 4 small ceiling speakers to current set up
-replacement of Front LR and SL/SR to speakers that also fire upwards at an angle (IE: Atmos speakers)

Is this true?
No need for new LR and Surround speakers..

Just add the 4 ceiling speakers, or 4 stand alone upward firing modules... and the AVR.
 
#4,426 ·
It's 640 kilobits/sec on some streamed files... just not from Netflix, those are compressed further (and often sound lousy).
Yes Dan, DD+ is 640 kbps (Blu-rays), and it can be lower too like you just said (from streaming, Netflix, etc.).
...Markus seems to like it, and wikipedia has another technical way of saying it.

* If the first batch of Dolby Atmos AVRs & SSPs have a Dolby Surround "upmixer", I hope it works with Dolby TrueHD. I have a decent number of them Blu-rays with such encoding (10% of 4,000 is roughly 400).

And Netflix and downloading I never used of my entire life. ...Don't know how and not interested.
But bravo to all who do (voodoo). ;)
 
#4,428 · (Edited)
So no top rears?
The Denon's used with 2 pair of elevated speakers let you set six different combinations of Front Height / Top Front/Middle/Rear / Rear-Height, including the one I suggested. You just leave out the adjacent combinations.

It goes without saying that following Roger Dressler's suggestion and try to reposition the Surround Rear to ear level instead, would be better!

Have you considered to not use Back Surrounds, but use Wides instead? (Although that option is not 100% certain to be possible now even if the Denon 7200 has that output via pre-out)
 
#4,430 ·
But you don't have to use them. I'd say more than half the features on my Onkyo 5509 have never been used (by me).
Now that there is auite a good guideline to calculate positions of speakers in regards to the distance between front and back wall I was wondering what the best way is in regards to distances between the side walls.
My room is about 4.5m wide and my main speakers are located directly in the corner of the wall. .Following the guidance of the speaker manufacturer my back surrounds are a little bit more inward sp having about 1m distance to the right respective left wall. If I would install ceiling speakers in the same way leaving 1m to each side they have roughly 2m between each other. Would that make sense?
 
#4,431 ·
No need for new LR and Surround speakers..

Just add the 4 ceiling speakers, or 4 stand alone upward firing modules... and the AVR.
In a 13x11 viewing area. Would you still need 4 ceiling speakers? I only mentioned surrounds because in the pioneer picture that has become popular around here shows both the towers and bookshelves firing upward, in so giving you 4 ceiling "spots". If you put these modules on the sidewalls I really won't have room for them. So it's new speakers or ceiling speakers for me.
 
#4,432 ·
Oh but I did check your link Markus. Now, streaming DD+ you can get 6.144 Megabits per second?
Is that uncompressed high resolution multichannel audio? ...Kilobits?

When you download or stream a movie from Netflix, Vudu, etc. what is their highest res?
...Better than Blu-ray?
Yes, DD+ can do higher bitrates and it might even do more single objects than TrueHD. It is lossy but who cares if it's good enough.

It's 640 kilobits/sec on some streamed files... just not from Netflix, those are compressed further (and often sound lousy).
That's something we'll have to see when the first implementations arrive. Currently there is no Atmos streaming.
By the way, see Roger's previous post:

That is unlikely to happen with DD+ ATMOS. One cannot simply decode and re-encode as with 5.1 audio. The decoded audio is not in a form usable by the second encoder.
 
#4,433 · (Edited)
I have fed all Denon's suggested side-elevation angles to the cool German calculator, using my ceiling height of 260 cm minus the speaker size (the JBLpro SCS 8 coaxial is my current n°1). The center of the coaxial ceiling mounts will be at 240 cm [8'] minus 90 cm ear height [3'] = 150 cm [5']

http://www.arndt-bruenner.de/mathe/scripts/dreiecksberechnungrw.htm

Outcome is the distance ahead [↑] or behind [↓] MLP on the axis MLP - screen center.

FH: 30 to 45° ↑260 to ↑150 cm [↑8'8" to ↑5']
TF: 30 to 55° ↑260 to ↑105 cm [↑8'8" to ↑3'6"]
TM: 65 to 100° ↑70 to ↓25 cm [↑2'4" to ↓0'10"]
TR: 125 to 150° ↓105 to ↓260 cm [↓3'6" to ↓8'8"]
RH: 135 to 150° ↓150 to ↓260 cm [↓5' to ↓8'8"]

If anyone finds this helpful, I could do a few more between 7' and 10' ceiling heights.
 
#4,434 ·
Yes Dan, DD+ is 640 kbps (Blu-rays), and it can be lower too like you just said (from streaming, Netflix, etc.).
...Markus seems to like it, and wikipedia has another technical way of saying it.
Markus never said he likes it. Please stick to what I've said and don't make up things.
 
#4,435 ·
In a 13x11 viewing area. Would you still need 4 ceiling speakers?
The actual size of the space is not really relevant. Two ceiling speakers only form a one-dimentional line so they can only produce sound coming from the line between them. Four ceiling speakers form a two-dimentional plane, hence the sound they produce can come from anywhere on that plane. It will be far superior.

And ofcourse two speakers will not really give you the sense of total envelopment that four will do.
 
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#4,436 ·
The actual size of the space is not really relevant. Two ceiling speakers only form a one-dimentional line so they can only produce sound coming from the line between them. Four ceiling speakers form a two-dimentional plane, hence the sound they produce can come from anywhere on that plane. It will be far superior.

And ofcourse two speakers will not really give you the sense of total envelopment that four will do.
I see, makes sense. Would adding 4 ceiling speakers to 5.1 make it essentially 9.1? I'm not sure how the lingo works here since I've always had 5.1. I consider doing front wides in the front LR corner ceiling. Would that even be recommended with a 4 ceiling atmos set up? I'm just curious how 7.1 systems might change with atmos. IE: which speakers would be less useful? Sides, front heights, front wides, etc. .
 
#4,437 · (Edited)
I see, makes sense. Would adding 4 ceiling speakers to 5.1 make it essentially 9.1? I'm not sure how the lingo works here since I've always had 5.1. I consider doing front wides in the front LR corner ceiling. Would that even be recommended with a 4 ceiling atmos set up? I'm just curious how 7.1 systems might change with atmos. IE: which speakers would be less useful? Sides, front heights, front wides, etc. .
It would be called 5.1.4 in Dolby Atmos speak. Front Wides should be at the same height as the Side Surrounds. With Atmos, that height should ideally be ear height.

BTW, Rear Surrounds can also be on the side wall at about +/- 135° if that would suit your room. Then the Side Surrounds can be recommended even at +/- 75° which would put them somehow ahead of MLP. Together with 4 ceiling speakers, this would be a superb 7.1.4 layout, only possible to be improved upon marginally by 9.1.4. But at a much bigger cost, since the former can be done with, for example, a Marantz AV7702, while the latter would need to use a AV8802 (besides two more Surround speakers and amps ofcourse). And it's not even confirmed yet if the AV8802 will process 13 channels simultaneously.
 
#4,438 ·
I was referring exactly to DD+ - Highly compressed audio @ 640 kbps (MP3 type of resolution, @ the very best).

You're saying DD+ is like MP3? That's like saying HEVC is like MPEG1.

I've read your post totally correctly. ...DD+ (compressed audio @ 640 kbps),
and not DD (compressed audio @ 192 - 384/448 kbps).

DD runs from 32kbps to 640kbps. DD+ goes from 32kbps to 6144kbps but is designed for extremely low bitrate applications (i.e. streaming) and to overcome the 5.1 channel limitation of DD
 
#4,439 ·
It was discussed in this thread, this was the first I heard about its irrelevance.

This release of Atmos is all about ceiling channels.
Since theater speaker are already above, ceiling channels are more above.
Perhaps, that presents a larger opportunity in the home environment.


Earlier discussion of Atmos centered around the flexibility or object oriented sound that would have greater control of mapping sound onto the individual's speaker configuration and allow users to tune the sound to their preferences.

That is very intriguing and I look forward to that advancement (FilmMixer has alluded to more to come).
When I go to any theater Atmos or otherwise, the most striking aspect is the size of the center channel. Object oriented sound could be used to recreate this effect at home. Right-now, it is uncertain which vender will provide that advancement. Time will tell.

- Rich
Sorry, I have no idea what you are talking about. The discussion you joined in to was about the use of 3 or 5 speakers across the front. You replied with a comment about upfiring speakers, which was not relevant in any way to that discussion and have now wandered further away from it still.
 
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