Ask the Editors: Are Dolby Atmos-Enabled Speakers Special? - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 42 Old 09-29-2015, 04:07 PM - Thread Starter
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Ask the Editors: Are Dolby Atmos-Enabled Speakers Special?

Q: Are Dolby Atmos Enabled speakers special? I have KEF Q900 tower speakers and want to use a pair of KEF Q15s as Atmos speakers on top of the towers. What angle should they be aimed at the ceiling?

- AlanAbby

A: I'm glad you asked about implementations of Dolby Atmos that do not conform to the company's guidelines. I've spent the better part of the past year toying with various Atmos configurations in my studio, as well as attending many demos, and in the process, I've tried various approaches similar to what you are asking about.

But before I get to that, let's review what Atmos-enabled speakers are. Dolby Atmos is an audio format that adds overhead speakers to a standard surround array. You can mount speakers directly on or in the ceiling, or you can use "Atmos-enabled" speakers that point up at the ceiling, which reflects their sound back down to the listeners, creating the effect of sound coming from overhead. Atmos-enabled speakers integrate upfiring speakers on top of conventional front-firing speakers, while Atmos "modules" are separate speakers normally placed on or near the front LR and/or surround LR speakers.


Atmos-enabled speakers bounce sound off the ceiling to create height channels.

The answer to your first question—are Atmos-enabled speakers special?—is yes. The angle at which Atmos modules fire sound at the ceiling is just one factor in a proper Atmos-enabled speaker design. Other crucial considerations include dispersion characteristics and maintaining proper phase in 2-way designs.

Some Atmos-enabled speakers and modules use concentric drivers, while others employ one or more full-range drivers. Furthermore, good Atmos-oriented reflected-sound speaker designs use absorptive materials around the driver(s) to limit sound leaks to the sides.

Controlled dispersion is key to achieving the illusion that audio is coming from above. You only want to hear the reflected sound that bounces off the ceiling, not sound directly from the upfiring speaker itself. In order to achieve the best height effects, you want the beams of sound to be behave like spotlights, not floodlights.

One key differentiating factor between a standard bookshelf-style speaker and an Atmos module is the inclusion of a hardware circuit built into each module or speaker. Dolby says the processing it performs enhances the sense of sound coming from overhead. Manufacturers have to pay Dolby a licensing fee to include this technology in a design, and without it, a speaker does not qualify as Atmos-enabled.

When I first started experimenting with Atmos, using compact 2-way bookshelf speakers in a reflected-sound configuration produced good results. As I experimented, I discussed the use of satellite and bookshelf-style speakers for the reflected-sound channels with Dolby engineers as well as several speaker designers. While they did not explicitly endorse this sort of experimentation, I gleaned that it was OK to experiment as long as you understand the challenges you face.

Fortunately, Atmos for the home is robust and adaptable. If you keep a few key concepts in mind while experimenting with reflected-sound speaker arrangements, you should succeed in achieving 3D audio immersion without necessarily following Dolby's guidelines to the letter.

Let's discuss what you can do to implement Atmos using reflected sound and your KEF Q15s. It's 100% possible to get a good result—I know because I've done it using a number of different compact bookshelf speakers. The key to success is understanding how to coax the speakers you use into behaving more like well-designed Atmos modules than wide-dispersion bookshelf or satellite speakers.

During my experimentation, I found it was better to tell the system I was using standard in-ceiling speakers for height channels, rather than Atmos-enabled speakers. This let me choose the crossover point rather than using the predefined crossover prescribed by Dolby.

I determined that a 120 Hz crossover worked well for my reflective-sound system. The danger in using a lower crossover is that the low frequencies are omnidirectional, and they arrive at your ears directly from the speaker a lot earlier than the midrange and treble, which must travel up to the ceiling and back.

The KEF Q15 is an interesting choice for this application because it features a concentric 2-way driver, which turns out to be an optimum design for reflected-sound Atmos applications. KEF and Pioneer Elite both use concentric drivers in their Atmos-enabled products. However, it is quite possible that the dispersion of the Q15s is too wide to be optimal. There are two ways to solve this problem: add some padding/absorptive material around the driver to control sound leakage—an approach used in many official Atmos-enabled speakers—or elevate the speakers.

According to Dolby, the reflected-sound modules do not need to be directly above the speaker channel they pair with—there's about three feet of leeway for positioning. The best use of that leeway is to elevate the modules (or the speakers you are trying to use as modules) several feet above the tops of the corresponding ear-level speakers in the system. One option is to use short speaker stands on top of the main speakers. This simple act will ensure that you hear more reflected sound and less leakage.

If you can add acoustically absorptive padding around the driver and raise the whole contraption a foot or two, that is sure to produce the best result.

When it comes to the question of what is the optimal angle for the reflected-sound speakers, I recommend that you experiment to see what creates the best effect. The ideal angle will vary a bit depending on room size and seating position, but the goal is to make the reflected sound appear to come from the same spots you'd place ceiling-mounted speakers in an optimal configuration—that is, slightly in front of and (if you're using more than two upfiring speakers) behind the listening position.

One of the best ways to know if an improvised Atmos reflected-sound system is working properly is to run the automatic speaker configuration utility on the AVR or pre/pro. The system should report distances for the height channels that are consistent with the total distance from the speaker to the ceiling and then to the listening position.

If the automatic measurements don't include the extra distance required for the reflection, that's a sure sign it's not going to work because it means sound emanating directly from the speaker is louder than the reflected sound. For a proper Atmos effect, the reflected sound has to be louder than the direct sound.

If you take care to properly deal with the dispersion of your reflected-sound speakers, you'll likely achieve a good result. On the other hand, if you simply place bookshelf or satellite speakers (like the KEF Q15s) directly on top of existing tower speakers and wedge something underneath it, chances are the result will not sound very good. It's certainly worth experimenting if you already have the KEF Q15s on hand; you could well like what you hear.

If you've got an AV question, please send it to Scott Wilkinson (scott@avsforum.com) or Mark Henninger (imagic, mark@avsforum.com) via PM or email.
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post #2 of 42 Old 09-29-2015, 07:03 PM
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Don't forget the EQ Dolby applies. Markus posted miniDSP biquads in one of the Atmos threads.

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post #3 of 42 Old 10-01-2015, 06:27 AM - Thread Starter
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Originally Posted by DS-21 View Post
Don't forget the EQ Dolby applies. Markus posted miniDSP biquads in one of the Atmos threads.
Do you mean the circuit/filter in the licensed Atmos-enabled speakers that incorporate a HRTF (head-realted transfer function)? It may help if there is excess leaked sound, but the sound that's coming from above creates the real HRTF when it bounces off your shoulders. So, if you manage to get most of the sound to reflect off the ceiling by raising the height speakers and using sound absorbing material (to limit dispersion) then the "natural" HRTF will do its thing.

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The HRTF processing ('height filter') is described in Dolby's patents, e.g. WO2014107714A1. They obviously think that adding two HRTFs (one in the speaker response and one created by your own head and torso) is better than one.

My question would be, did you really perceive the sound as distinctively coming from the ceiling? Or was it more like a very spacious version of a sound coming from where the speaker is located?

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post #5 of 42 Old 10-01-2015, 07:22 AM
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Quote:
Originally Posted by imagic View Post
Do you mean the circuit/filter in the licensed Atmos-enabled speakers that incorporate a HRTF (head-realted transfer function)?
Yes, that's "EQ" in too many words

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Originally Posted by imagic View Post
It may help if there is excess leaked sound, but the sound that's coming from above creates the real HRTF when it bounces off your shoulders.
Be that as it may, the Atmos reflecting speaker configuration is indisputably designed with that EQ curve in place. IMO to get the result intended one should apply that EQ curve. Fortunately, there are instructions in the big Atmos thread somewhere how to do so with miniDSP and with Yamaha AVRs. I know Markus wrote the biquads for the miniDSP units. I don’t remember off hand who posted the programming for Yamaha AVRs.

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So, if you manage to get most of the sound to reflect off the ceiling by raising the height speakers and using sound absorbing material (to limit dispersion) then the "natural" HRTF will do its thing.
Perhaps. but at the same time it’s worth noting that the commercial Atmos modules from better designers (e.g. Elac, Debut KEF, Pioneer) don’t have any sound absorbing material on the baffle to limit dispersion, though. A speaker like the questioner's KEF Q15 (polar map available at gedlee.com, and incidentally an Andrew Jones design IIRC, just like the Pioneer and Elac Debut Atmos modules) would likely be very good in this role.

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post #6 of 42 Old 10-01-2015, 07:50 AM - Thread Starter
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Quote:
Originally Posted by DS-21 View Post
Yes, that's "EQ" in too many words



Be that as it may, the Atmos reflecting speaker configuration is indisputably designed with that EQ curve in place. IMO to get the result intended one should apply that EQ curve. Fortunately, there are instructions in the big Atmos thread somewhere how to do so with miniDSP and with Yamaha AVRs. I know Markus wrote the biquads for the miniDSP units. I don’t remember off hand who posted the programming for Yamaha AVRs.



Perhaps. but at the same time it’s worth noting that the commercial Atmos modules from better designers (e.g. Elac, Debut KEF, Pioneer) don’t have any sound absorbing material on the baffle to limit dispersion, though. A speaker like the questioner's KEF Q15 (polar map available at gedlee.com, and incidentally an Andrew Jones design IIRC, just like the Pioneer and Elac Debut Atmos modules) would likely be very good in this role.
Sure, no reason you can't replicate/clone the measured EQ curve and apply something similar if you have parametric EQ available. And on the flip-side, Klipsch says its Atmos-enabled modules can also be wall-mounted and used as standard surrounds... weird, huh?

The lack of sound absorbing material on the modules might have to do with pragmatic/aesthetic limitations.

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Originally Posted by markus767 View Post
The HRTF processing ('height filter') is described in Dolby's patents, e.g. WO2014107714A1. They obviously think that adding two HRTFs (one in the speaker response and one created by your own head and torso) is better than one.

My question would be, did you really perceive the sound as distinctively coming from the ceiling? Or was it more like a very spacious version of a sound coming from where the speaker is located?
Yup. Now, well-designed and properly placed in-ceiling speakers are better (IMO) but in my experiments, I achieved reflected-sound results with hacked Atmos that (again IMO) beat what I have achieved so far with official licensed modules in terms of creating actual objects in a 3D soundfield, and not just overhead ambience. Nothing improves the sound of a reflected Atmos system as much as raising the height speakers a foot or two above the ear-level speakers they are paired with.

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Originally Posted by imagic View Post
Yup. Now, well-designed and properly placed in-ceiling speakers are better (IMO) but in my experiments, I achieved reflected-sound results with hacked Atmos that (again IMO) beat what I have achieved so far with official licensed modules in terms of creating actual objects in a 3D soundfield, and not just overhead ambience. Nothing improves the sound of a reflected Atmos system as much as raising the height speakers a foot or two above the ear-level speakers they are paired with.
Just to make sure we're not talking at cross-purposes. Did you play sound through a single reflected sound speaker and perceive the sound coming distinctively from the ceiling?

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post #9 of 42 Old 10-01-2015, 08:19 AM - Thread Starter
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Just to make sure we're not talking at cross-purposes. Did you play sound through a single reflected sound speaker and perceive the sound coming distinctively from the ceiling?
Yes, that's pretty much the first thing I did. If something does not meet that threshold I'm not going to listen to it. I definitely do listen to "height only" as well as run the Atmos demo loops, which have very obvious, discrete height effects in them. I've heard far too many Atmos demos, and set up too many systems in my studio, to settle for some smeary ambient mess. My standard for a good Atmos experience is that it offer the ability to track individual sound objects in 3D space.

Oh, and I've certainly heard some dismal Atmos demos, too. And my own experiments did not work right away, hence the tweaks I prescribed. However, I did not attempt to replicate the HRTF "bump and notch"
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I still think that if you love movies and multichannel, you will definitely love atmos and should consider "doing it right" with actual real channels in as many standard speaker locations as possible.

I suppose the technical dilemma of wiring and placing new speakers will ultimately make "atmos speakers" the only way to get any real adoption numbers...

Most people would be laughing if one suggested listening to stereo off of a phantom image from reflections off the ceiling.

It also seems like dolby is going to continue their 7.4.1 standard arrangement ... sigh... I guess you have to start somewhere.

2 channel: you are old school
3 channel: you are hard of hearing and need that center channel
5.1: you are "normal" and have little black cubes everywhere
7.1: you are obsessing just a little bit
11.1 matrixed: you are likely just a little bit delusional but boy don't those wides sound cool?
15+ channels: you are clearly insane.
7.4 with atmos upfiring speakers: you are insane, delusional, and perhaps straight up lazy...
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I still think that if you love movies and multichannel, you will definitely love atmos and should consider "doing it right" with actual real channels in as many standard speaker locations as possible.

I suppose the technical dilemma of wiring and placing new speakers will ultimately make "atmos speakers" the only way to get any real adoption numbers...

Most people would be laughing if one suggested listening to stereo off of a phantom image from reflections off the ceiling.

It also seems like dolby is going to continue their 7.4.1 standard arrangement ... sigh... I guess you have to start somewhere.

2 channel: you are old school
3 channel: you are hard of hearing and need that center channel
5.1: you are "normal" and have little black cubes everywhere
7.1: you are obsessing just a little bit
11.1 matrixed: you are likely just a little bit delusional but boy don't those wides sound cool?
15+ channels: you are clearly insane.
7.4 with atmos upfiring speakers: you are insane, delusional, and perhaps straight up lazy...
My Erskine theater has upfiring speakers. I'm not sure laziness has anything to do with it. Sometimes they might be the best option.
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post #12 of 42 Old 10-01-2015, 09:19 PM
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Most people would be laughing if one suggested listening to stereo off of a phantom image from reflections off the ceiling.
Ahem...

http://www.audiokinesis.com/dream-maker-lcs.html

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post #13 of 42 Old 10-01-2015, 11:38 PM
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Yes, the idea isn't exactly new:
http://www.carlssonplanet.com/history.php

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post #14 of 42 Old 10-02-2015, 04:34 AM - Thread Starter
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Yes, the idea isn't exactly new:
http://www.carlssonplanet.com/history.php
And then there's this: http://uk.yamaha.com/en/products/aud..._g/?mode=model

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Yep, Yamaha bought the IP from http://www.cambridgemechatronics.com
https://web.archive.org/web/20120111...logy/audio_DSP

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I should rephrase... most audio dorks like us that hang around these forums... would be laughing...

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I should rephrase... most audio dorks like us that hang around these forums... would be laughing...
I wouldn't.

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I wouldn't.
So am I to assume that you think that reflections are going to be a standard way of transmitting audio? Or perhaps will sound as accurate as direct radiating sound? What is the take home message here?

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Is everyone talking about those up firing spks that go on top of your mains,if so why couldn't you buy a bookshelf spk, and angle it up,wouldn't that be cheaper?
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So am I to assume that you think that reflections are going to be a standard way of transmitting audio? Or perhaps will sound as accurate as direct radiating sound? What is the take home message here?
I know this question wasn't directed at me, but the extra dispersion created by upfiring speakers was needed because of my low ceilings. With really high ceilings I'd rather use direct radiating.
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Uhhhh,

The Auro3D system makes the most sense to me as far as typical living rooms and not dedicated theater rooms.

Found a review on the Auro 3D system VS Atmos and they preferred the Auro 3D.

http://rslspeakers.com/dolby-atmos-vs-auro-3d/

If you had to have the "voice of God" center mounted ceiling speaker--just make it look like a light or something. It is only one so modify the ceiling fan by placing the speaker in the center and the lights around the sides. Since the surround speakers (and speakers in general) have their space, not hard to place another speaker above it at the ceiling/wall junction.

For now, I'll just ignore Atmos and pay attention to Auro3D to figure out how well it works in AVRs. Since 3D video seems to be dead, sometimes it is a good idea to sit back and see if the tech moves. My wife don't want holes in the ceiling with grills and I don't want sound bouncing speakers knowing they are a simulation so not worth the effort.

Maybe the best format win and I hope they both don't die like 3D televisions before they get the tech correct.
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So am I to assume that you think that reflections are going to be a standard way of transmitting audio? Or perhaps will sound as accurate as direct radiating sound? What is the take home message here?
Without reflections there's no spaciousness, no apparent source width, no envelopment, no believeable auditory scene. Some recording techniques and speaker configurations aren't capable of delivering said reflections hence speakers utilizing the room as a 'mechanical effects processor' is nothing I would laugh at.

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Q: Are Dolby Atmos Enabled speakers special? I have KEF Q900 tower speakers and want to use a pair of KEF Q15s as Atmos speakers on top of the towers. What angle should they be aimed at the ceiling?

- AlanAbby

A: I'm glad you asked about implementations of Dolby Atmos that do not conform to the company's guidelines. I've spent the better part of the past year toying with various Atmos configurations in my studio, as well as attending many demos, and in the process, I've tried various approaches similar to what you are asking about.

But before I get to that, let's review what Atmos-enabled speakers are. Dolby Atmos is an audio format that adds overhead speakers to a standard surround array. You can mount speakers directly on or in the ceiling, or you can use "Atmos-enabled" speakers that point up at the ceiling, which reflects their sound back down to the listeners, creating the effect of sound coming from overhead. Atmos-enabled speakers integrate upfiring speakers on top of conventional front-firing speakers, while Atmos "modules" are separate speakers normally placed on or near the front LR and/or surround LR speakers.


Atmos-enabled speakers bounce sound off the ceiling to create height channels.

The answer to your first question—are Atmos-enabled speakers special?—is yes. The angle at which Atmos modules fire sound at the ceiling is just one factor in a proper Atmos-enabled speaker design. Other crucial considerations include dispersion characteristics and maintaining proper phase in 2-way designs.

Some Atmos-enabled speakers and modules use concentric drivers, while others employ one or more full-range drivers. Furthermore, good Atmos-oriented reflected-sound speaker designs use absorptive materials around the driver(s) to limit sound leaks to the sides.

Controlled dispersion is key to achieving the illusion that audio is coming from above. You only want to hear the reflected sound that bounces off the ceiling, not sound directly from the upfiring speaker itself. In order to achieve the best height effects, you want the beams of sound to be behave like spotlights, not floodlights.

One key differentiating factor between a standard bookshelf-style speaker and an Atmos module is the inclusion of a hardware circuit built into each module or speaker. Dolby says the processing it performs enhances the sense of sound coming from overhead. Manufacturers have to pay Dolby a licensing fee to include this technology in a design, and without it, a speaker does not qualify as Atmos-enabled.

When I first started experimenting with Atmos, using compact 2-way bookshelf speakers in a reflected-sound configuration produced good results. As I experimented, I discussed the use of satellite and bookshelf-style speakers for the reflected-sound channels with Dolby engineers as well as several speaker designers. While they did not explicitly endorse this sort of experimentation, I gleaned that it was OK to experiment as long as you understand the challenges you face.

Fortunately, Atmos for the home is robust and adaptable. If you keep a few key concepts in mind while experimenting with reflected-sound speaker arrangements, you should succeed in achieving 3D audio immersion without necessarily following Dolby's guidelines to the letter.

Let's discuss what you can do to implement Atmos using reflected sound and your KEF Q15s. It's 100% possible to get a good result—I know because I've done it using a number of different compact bookshelf speakers. The key to success is understanding how to coax the speakers you use into behaving more like well-designed Atmos modules than wide-dispersion bookshelf or satellite speakers.

During my experimentation, I found it was better to tell the system I was using standard in-ceiling speakers for height channels, rather than Atmos-enabled speakers. This let me choose the crossover point rather than using the predefined crossover prescribed by Dolby.

I determined that a 120 Hz crossover worked well for my reflective-sound system. The danger in using a lower crossover is that the low frequencies are omnidirectional, and they arrive at your ears directly from the speaker a lot earlier than the midrange and treble, which must travel up to the ceiling and back.

The KEF Q15 is an interesting choice for this application because it features a concentric 2-way driver, which turns out to be an optimum design for reflected-sound Atmos applications. KEF and Pioneer Elite both use concentric drivers in their Atmos-enabled products. However, it is quite possible that the dispersion of the Q15s is too wide to be optimal. There are two ways to solve this problem: add some padding/absorptive material around the driver to control sound leakage—an approach used in many official Atmos-enabled speakers—or elevate the speakers.

According to Dolby, the reflected-sound modules do not need to be directly above the speaker channel they pair with—there's about three feet of leeway for positioning. The best use of that leeway is to elevate the modules (or the speakers you are trying to use as modules) several feet above the tops of the corresponding ear-level speakers in the system. One option is to use short speaker stands on top of the main speakers. This simple act will ensure that you hear more reflected sound and less leakage.

If you can add acoustically absorptive padding around the driver and raise the whole contraption a foot or two, that is sure to produce the best result.

When it comes to the question of what is the optimal angle for the reflected-sound speakers, I recommend that you experiment to see what creates the best effect. The ideal angle will vary a bit depending on room size and seating position, but the goal is to make the reflected sound appear to come from the same spots you'd place ceiling-mounted speakers in an optimal configuration—that is, slightly in front of and (if you're using more than two upfiring speakers) behind the listening position.

One of the best ways to know if an improvised Atmos reflected-sound system is working properly is to run the automatic speaker configuration utility on the AVR or pre/pro. The system should report distances for the height channels that are consistent with the total distance from the speaker to the ceiling and then to the listening position.

If the automatic measurements don't include the extra distance required for the reflection, that's a sure sign it's not going to work because it means sound emanating directly from the speaker is louder than the reflected sound. For a proper Atmos effect, the reflected sound has to be louder than the direct sound.

If you take care to properly deal with the dispersion of your reflected-sound speakers, you'll likely achieve a good result. On the other hand, if you simply place bookshelf or satellite speakers (like the KEF Q15s) directly on top of existing tower speakers and wedge something underneath it, chances are the result will not sound very good. It's certainly worth experimenting if you already have the KEF Q15s on hand; you could well like what you hear.

If you've got an AV question, please send it to Scott Wilkinson (scott@avsforum.com) or Mark Henninger (imagic, mark@avsforum.com) via PM or email.
Hi Mark, can I check what kind of "absorptive material" would you recommend in your experience?
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post #24 of 42 Old 10-03-2015, 09:34 PM
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Another question from me...

As I'm using a Dolby certified KEF R50 Atmos enabled speakers at this moment...does it make a difference if I choose pre-calibration setup for my speaker layout as "Height speakers" over "Dolby Atmos enabled speakers"...I presumed the latter should be the "correct" thing to do...but sometimes doing it "differently" may yield some surprisingly good results like what you did for your pseudo-Atmos enabled speaker setup when you decide to choose "height speakers" over Atmos enabled speakers.

Your thoughts?
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post #25 of 42 Old 10-04-2015, 01:24 PM
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I'd like to see a similar Q&A discussion thread specific to in/on ceiling Atmos speakers. I haven't seen a lot that are 'Atmos-certified' other than the recent Golden Ear review .. and I noticed that those have a uncommon angled design that provides some aiming as opposed to just down-firing. How important is it to have an 'Atmos certified' speaker as opposed to a good quality 'standard' ceiling speaker? What speaker qualities (concentric; wide dispersion; etc) are highly desired for the heights? Maybe these should be more like 'floods' than 'spots' .. to use your earlier analogy .. and maybe that recommendation depends on ceiling height (or not).

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post #26 of 42 Old 10-04-2015, 01:37 PM - Thread Starter
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Originally Posted by IanR View Post
I'd like to see a similar Q&A discussion thread specific to in/on ceiling Atmos speakers. I haven't seen a lot that are 'Atmos-certified' other than the recent Golden Ear review .. and I noticed that those have a uncommon angled design that provides some aiming as opposed to just down-firing. How important is it to have an 'Atmos certified' speaker as opposed to a good quality 'standard' ceiling speaker? What speaker qualities (concentric; wide dispersion; etc) are highly desired for the heights? Maybe these should be more like 'floods' than 'spots' .. to use your earlier analogy .. and maybe that recommendation depends on ceiling height (or not).
That is a good follow-up question and a discussion worth having.

Mark Henninger, Senior Editor at AVS Forum
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post #27 of 42 Old 12-30-2015, 06:43 PM
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That is a good follow-up question and a discussion worth having.
Mark .. this thread is now months old and I haven't really seen any other conversation around Atmos speakers considerations.. other than the long Atmos for the home one. However, I have seen the odd thread (including this one ) where people are still trying to at least understand the basic decision process even without getting into the technical details of speaker technology. I took a shot late in that thread of trying to create a sort of decision tree to attack some of the basic, speaker-independent stuff as follows:

Is your ceiling flat with no significant irregularities or sound treatments and at least 7.5 feet high?
No: Do you rent or own?
Rent: Are you interested/capable/able to mount speakers on the ceiling .. and, if appropriate, does it meet WAF/SO approval?
No: You're screwed .. Atmos isn't for you unless someone builds an Atmos sound bar
Yes: Buy/build concentric driver speakers and mount them to the ceiling angled toward the main listening position
Own: Buy/build concentric driver speakers and mount them to the ceiling angled toward the main listening position
Yes: Are you interested/capable/able to mount speakers on the ceiling .. and, if appropriate, does it meet WAF/SO approval?
No: Buy/build Atmos enabled speakers/modules
Yes: You have a choice to Buy/build Atmos enabled speakers/modules or to buy/build concentric driver speakers and mount them to the ceiling angled toward the main listening position but the general and growing trend is that ceiling mounted is preferred over upfiring all other things being equal especially in home theaters where the owner is in control of most of the decisions.
Once you get through those basic questions, there are still some technical ones that I've been thinking about. For example, how strong a recommendation is it to have concentric drivers? There seems to be a growing thought that you need them but it would be nice to see it confirmed. And can I use Atmos-enabled standalone modules and ceiling mount them? Pioneer has some in their Andrew Jones line and they'd probably be a nice timbre match for my fronts but I think either type (integrated or modules) of up-firing has been designed/altered to reduce the dispersion while ceiling mounted Atmos speakers are supposed to have a wide dispersion to reduce localization. But maybe the resulting ceiling reflections from an up-firing Atmos speaker are essentially 'widely dispersed' anyway after travelling twice the distance of ceiling mounts.

Sorry for the 20 questions .. Happy New Year in advance.

Ian

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post #28 of 42 Old 12-30-2015, 11:56 PM
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Once you get through those basic questions, there are still some technical ones that I've been thinking about. For example, how strong a recommendation is it to have concentric drivers? There seems to be a growing thought that you need them but it would be nice to see it confirmed. And can I use Atmos-enabled standalone modules and ceiling mount them? Pioneer has some in their Andrew Jones line and they'd probably be a nice timbre match for my fronts but I think either type (integrated or modules) of up-firing has been designed/altered to reduce the dispersion while ceiling mounted Atmos speakers are supposed to have a wide dispersion to reduce localization. But maybe the resulting ceiling reflections from an up-firing Atmos speaker are essentially 'widely dispersed' anyway after travelling twice the distance of ceiling mounts.
Strong recommendation of using coax drivers for upfiring modules as they don't show the pronounced lobing of multi-way speakers. The dispersion pattern should be rather narrow though. I'm using fullrange drivers with good results.

Atmos-enabled speakers have a non-flat on-axis response so they should not be used as direct firing speakers, e.g. mounted on the ceiling.

Wide dispersion is necessary for delivering similar direct sound to multiple seats. As a by-product the room gets "illuminated" more than it should which creates louder reflections which can blur sound localization. This isn't a desirable effect. Single speakers should be localizable as much as possible. In a multichannel system the recording should deliver the necessary reflections that will make sounds more or less blurry/spacious.

Markus

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Last edited by markus767; 01-01-2016 at 04:20 AM.
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Reminds me of HD 'enabled' antennas.
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Atmos-enabled speakers have a non-flat on-axis response so they should not be used as direct firing speakers, e.g. mounted on the ceiling.
Tks

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