Why can't bookshelf type speakers be used for atmos?

[Danzilla31]

Hey guys I was discussing with a friend on here Using some speakers for heights for atmos a bookshelf type either ported or sealed

I feel although they need to be necessary for some rooms due to constraints that in walls and in ceiling speakers are still a compromise

When discussing this with a friend on here whose knowledge I value he told me that in ceiling or in walls are better to be installed for heights on the ceiling

Something about regular speakers aren't built to handle the diffraction the ceiling causes

But what if a speaker was mounted like this?

These are 4 inches out but can be moved out further and angled to listeners position anyway I want

Wouldn't a setup like this be superior to in ceiling wouldn't the ceiling be just like a wall they would be in front of anyway?

I'm not disputing my friends advice I posted this thread to learn more about the science and reasons behind why bookshelves couldn't be used like this for atmos

I'm hoping to start a fun thread where this can be discussed because I've never seen an exact thread on this subject. And I'm curious if floorstanders are superior then an in wall design why not put some good bookshelves up top for atmos if you can?

Thanks guys looking forward to your feedback

 

[William Lemmerhirt]

Hey dan! I agree with you. Bookshelf speakers can, and do make excellent atmos speakers. The problem is practicality. To many people, four of those would look stupid hanging off the ceiling(seen some setups like that. Kinda liked it!), and they can be harder to install. As far as diffraction and bsc and stuff, your right. It’s the exact same as a wall. Except above your head. Ifaik IW/IC speakers are designed to use the wall as a baffle so they have different baffle step compensation built in to the XO network. If you did want to mount some BS speakers on the ceiling, you could use a sound cloud, or some kind of absorption panels. IMO though, the content that’s used overhead, is designed to be used WITH the bed layer and the on screen action so I don’t know how much trouble it’s worth addressing the acoustic ceiling mounted BS speakers.

Sidenote, BS speakers can’t be used as atmos modules since they use a notch in the FR that’s engineered to help avoid localization.

Sidenote 2. The speakers in your pics have activated my AudiOCD. They’re too low.....must.......be...centered...on........the..screen.....
“Twitching”.......

 

[Danzilla31]

Hey dan! I agree with you. Bookshelf speakers can, and do make excellent atmos speakers. The problem is practicality. To many people, four of those would look stupid hanging off the ceiling(seen some setups like that. Kinda liked it!), and they can be harder to install. As far as diffraction and bsc and stuff, your right. It’s the exact same as a wall. Except above your head. Ifaik IW/IC speakers are designed to use the wall as a baffle so they have different baffle step compensation built in to the XO network. If you did want to mount some BS speakers on the ceiling, you could use a sound cloud, or some kind of absorption panels. IMO though, the content that’s used overhead, is designed to be used WITH the bed layer and the on screen action so I don’t know how much trouble it’s worth addressing the acoustic ceiling mounted BS speakers.

Sidenote, BS speakers can’t be used as atmos modules since they use a notch in the FR that’s engineered to help avoid localization.

Sidenote 2. The speakers in your pics have activated my AudiOCD. They’re too low.....must.......be...centered...on........the..screen.....
“Twitching”.......

Hah hah thanks for the info my friend! I'm moving to the new house in about 2 weeks so I just put them up there like that for now

I also put them a little lower then the TV because my listening position is the bed and when laying there that is perfectly ear level I can't lower the TV tho to match them not enough space

 

[ryanosaur]

And with a rear port and you're Proper Fukkd. That's what I'm going to be doing is mounting Standmounts as my Atmos. You know as well as anybody that we all have to work with what we got. sometimes you can hollow out your ceiling. Sometimes not. Sometimes, you have to put a speaker in a nook... sometimes you have to laugh and realize that maybe you are just meant to listen to 2.2 audio!
But along the lines of what William was saying... if you have the opportunity to do the Infinite Baffle approach, that is probably best, otherwise you have to pick your poison. I would love to have front ports on my speakers that I plan on Atmosing (that's a word, ya? ), but have rears. Sealed may be better, but then again.... Likewise, probably a horn loaded speaker is better than a wide dispersion. I'm actually considering future DIY Atmos speakers that will use a coaxial driver. We'll see, but in theory the quasi-horn loaded approach seems reasonable. Time will tell!

 

[Danzilla31]

And with a rear port and you're Proper Fukkd. That's what I'm going to be doing is mounting Standmounts as my Atmos. You know as well as anybody that we all have to work with what we got. sometimes you can hollow out your ceiling. Sometimes not. Sometimes, you have to put a speaker in a nook... sometimes you have to laugh and realize that maybe you are just meant to listen to 2.2 audio!
But along the lines of what William was saying... if you have the opportunity to do the Infinite Baffle approach, that is probably best, otherwise you have to pick your poison. I would love to have front ports on my speakers that I plan on Atmosing (that's a word, ya? ), but have rears. Sealed may be better, but then again.... Likewise, probably a horn loaded speaker is better than a wide dispersion. I'm actually considering future DIY Atmos speakers that will use a coaxial driver. We'll see, but in theory the quasi-horn loaded approach seems reasonable. Time will tell!

Those speakers are sealed I love those things I can put them in so many places thanks to that sealed design and they are good to go.

 

[Danzilla31]

And with a rear port and you're Proper Fukkd. That's what I'm going to be doing is mounting Standmounts as my Atmos. You know as well as anybody that we all have to work with what we got. sometimes you can hollow out your ceiling. Sometimes not. Sometimes, you have to put a speaker in a nook... sometimes you have to laugh and realize that maybe you are just meant to listen to 2.2 audio!
But along the lines of what William was saying... if you have the opportunity to do the Infinite Baffle approach, that is probably best, otherwise you have to pick your poison. I would love to have front ports on my speakers that I plan on Atmosing (that's a word, ya? ), but have rears. Sealed may be better, but then again.... Likewise, probably a horn loaded speaker is better than a wide dispersion. I'm actually considering future DIY Atmos speakers that will use a coaxial driver. We'll see, but in theory the quasi-horn loaded approach seems reasonable. Time will tell!

I totally feel ya on the working with what we have

 

[shadyJ]

To be sure, you can use regular bookshelf speakers as ceiling mounted atmos speakers, but it is a very flawed approach for a few reasons. One is, as you know, that speaker is closer to a surface that is intended. That will increase diffraction and also boundary gain. If you tried to task a room correction EQ program like Audyssey to fix that, it will make a terrible mess. Ideally, the speakers you should use for that application should be engineered for that application.

Something else to consider is the difference between the horizontal and vertical dispersion patterns. Most bookshelf speakers were made to be listened to in a very narrow vertical angle, we are talking like +/- 15 degrees. outside of that, you get significant cancellation nulls as the difference in listening distance between the tweeter and woofer increases. Take a look at any of my bookshelf speaker reviews and compare the horizontal dispersion with the vertical dispersion. The exception to this is coaxial speakers. Also, bookshelf speakers where the tweeter is mounted very close to the woofer and has a high-order crossover can also do well here. But outside of speakers like that, you will be getting a sound with some big gulfs in the response unless you are sitting in a really tight angle of bookshelf speaker mounted on the ceiling.

If you want ceiling mounted speakers but not in-ceiling speakers, my advice is to use the JBL SCS-8. If you have a high ceiling, you could also get away with using some JBL Pro 9300 mounted on the wall, if they are high enough. If you don't need that kind of dynamic range, and want to save a few dollars, the SVS elevation speakers could also do well there.

 

[Danzilla31]

To be sure, you can use regular bookshelf speakers as ceiling mounted atmos speakers, but it is a very flawed approach for a few reasons. One is, as you know, that speaker is closer to a surface that is intended. That will increase diffraction and also boundary gain. If you tried to task a room correction EQ program like Audyssey to fix that, it will make a terrible mess. Ideally, the speakers you should use for that application should be engineered for that application.

Something else to consider is the difference between the horizontal and vertical dispersion patterns. Most bookshelf speakers were made to be listened to in a very narrow vertical angle, we are talking like +/- 15 degrees. outside of that, you get significant cancellation nulls as the difference in listening distance between the tweeter and woofer increases. Take a look at any of my bookshelf speaker reviews and compare the horizontal dispersion with the vertical dispersion. The exception to this is coaxial speakers. Also, bookshelf speakers where the tweeter is mounted very close to the woofer and has a high-order crossover can also do well here. But outside of speakers like that, you will be getting a sound with some big gulfs in the response unless you are sitting in a really tight angle of bookshelf speaker mounted on the ceiling.

If you want ceiling mounted speakers but not in-ceiling speakers, my advice is to use the JBL SCS-8. If you have a high ceiling, you could also get away with using some JBL Pro 9300 mounted on the wall, if they are high enough. If you don't need that kind of dynamic range, and want to save a few dollars, the SVS elevation speakers could also do well there.

Hmmmmmm okay now as I said I posted this thread to learn I can understand from your info why bookshelf speakers could present problems. Could you maybe help me to understand why the JBL SCS-8 would work so well? What design features do they have that keeps these issues from happening?
Is it the 120 x 120 dispersion. The wave guided horn there control of directivity?
Just wanting to learn
Also one last question
How do ceiling speakers overcome the dispersion issues? I understand from Williams posts the are designed to use the ceiling as a baffle. How do they overcome the dispersion issues you spoke about both vertical and horizontal?
Seems that there fixed placement and inability to direct them perfectly at the listener would create some issues

 

[Danzilla31]

Duh sorry Shady there a coaxial design overlooked that part in the specs but that makes me want to learn why are coaxial so effective as atmos on the ceiling?

Is it the fact that there is no distance between the woofer and tweeter?

 

[ryanosaur]

Duh sorry Shady there a coaxial design overlooked that part in the specs but that makes me want to learn why are coaxial so effective as atmos on the ceiling?

Is it the fact that there is no distance between the woofer and tweeter?

That’s my best guess, about coaxials: single point, woofer acts as horn/waveguide for tweeter. In my mind, cabinet size has a piece in it too, the coaxial may allow for that.
I’m only speculating here; hoping to learn more. But seems to make sense.

 

[shadyJ]

Duh sorry Shady there a coaxial design overlooked that part in the specs but that makes me want to learn why are coaxial so effective as atmos on the ceiling?

Is it the fact that there is no distance between the woofer and tweeter?

Since there is no distance from the tweeter to the acoustic center of the woofer, there is no way they can cancel each other out off axis. When drivers are separated by a distance, that creates a cancellation null at positions where the drivers are not the same distance from the listener. This is why there are all kinds of nulls that form on an off-axis response on a vertical plane of a typical speaker but the horizontal plane can often be very solid with no nulls. Note that an exception to that is horizontal MTM center speakers where woofers do see a distance difference as you move off horizontal axis, and so nulls form.

As for dispersion, there are a few different ways that is dealt with. Note that most ceiling speakers are coaxial, so they won't have off-axis cancellation. There are some ceiling speakers that are not coaxial designs, but they mostly have their own way of placing the tweeter as the true acoustic center of that speaker.

 

[kini]

Hmmmmmm okay now as I said I posted this thread to learn I can understand from your info why bookshelf speakers could present problems. Could you maybe help me to understand why the JBL SCS-8 would work so well? What design features do they have that keeps these issues from happening?
Is it the 120 x 120 dispersion. The wave guided horn there control of directivity?
Just wanting to learn
Also one last question
How do ceiling speakers overcome the dispersion issues? I understand from Williams posts the are designed to use the ceiling as a baffle. How do they overcome the dispersion issues you spoke about both vertical and horizontal?
Seems that there fixed placement and inability to direct them perfectly at the listener would create some issues

IMO you're over thinking it. For the most part Atmos effects are just that, effect sounds, occasional "voice of god". Pretty much any speaker will work. You can set the crossover to 120 or 150hz or higher if using "regular" speakers.

There are some Youtube videos comparing up firing, wall mounted at the ceiling and in ceiling. The wall mounted up at the intersection of the ceiling were nearly as effective as in ceiling.

 

[AcuDefTechGuy]

IMO you're over thinking it. For the most part Atmos effects are just that, effect sounds, occasional "voice of god". Pretty much any speaker will work. You can set the crossover to 120 or 150hz or higher if using "regular" speakers.

There are some Youtube videos comparing up firing, wall mounted at the ceiling and in ceiling. The wall mounted up at the intersection of the ceiling were nearly as effective as in ceiling.

I agree 100%.

I’ve been watching a lot Dolby Atmos and DTSX movies lately. I even started a thread on it.

It seems like 99% of the time it’s rain, thunder, aircrafts, fireworks, birds, voices, background music, etc.

It sounds very cool to me. I love it. But they are just overhead sound effects speakers, not like the main front 3 speakers.

 

[baronvonellis]

I'd like to use a Tang Band 4" speaker that's only $55. It's flat from 100-10khz with a bump at 15khz that would probably help with effects and "air" anyway. It naturally rolls off at 100hz or just cross it over there or at 80hz. Just need a cheap way to attach it to the corner of my ceilings.

 

[VonMagnum]

I use PSB CS500 speakers on the ceiling in the back. The can angle quite nicely. A guy I know that has a Trinnov uses the CS1000 for all six of his ceiling speakers so they can't be too bad. I use the PSB B15 in the front height on an actual bookshelf angled down with studio foam inserts. I also changed the tweeters to ones with very good off-axis response. Audyssey had no issues with correction.

 

[skybertie]

I was thinking along the lines of the OP... and can see the merits of the responses that point out dispersion and the need for concentric drivers... and using the ceiling as an infinite baffle...
But the other good point made here is they are "effects speakers" ... so I'm thinking... why not use car audio speakers... some very good co-axial designs... designed to work in a door (vs ceiling void) ... the power handling looks plenty for effects... And MUCH cheaper than anything with an "ATMOS" tag.
I'm even thinking of a trialing a couple of automotive pod speakers. They would only need a couple of screw holes in my ceiling while I experiment. I'm loath to cut 6inch holes in my ceiling until I understand the benefit. Once you have cut four holes that size you are kinda stuck with saying how great they are to folks that visit!

 

[William Lemmerhirt]

I was thinking along the lines of the OP... and can see the merits of the responses that point out dispersion and the need for concentric drivers... and using the ceiling as an infinite baffle...
But the other good point made here is they are "effects speakers" ... so I'm thinking... why not use car audio speakers... some very good co-axial designs... designed to work in a door (vs ceiling void) ... the power handling looks plenty for effects... And MUCH cheaper than anything with an "ATMOS" tag.
I'm even thinking of a trialing a couple of automotive pod speakers. They would only need a couple of screw holes in my ceiling while I experiment. I'm loath to cut 6inch holes in my ceiling until I understand the benefit. Once you have cut four holes that size you are kinda stuck with saying how great they are to folks that visit!

Well, a couple things in my mind quickly. They are “effects” speakers but not only do they provide overhead sounds, they also phantom image with the bed layer. So you really don’t want to use just anything. You don’t have to spend tons, but good speakers are still good speakers.
The other thing, is if you’re trying component speakers. They’re made for very close proximity listening and I think would not last long.

 

[afterlife2]

So what did you end up doing? I see this thread is a year old. This was my 2014 setup with dipole heights and they did a great job on rain, helicopters and planes. I enjoyed it throughly and budget wise too.

 

[Pogre]

Dan... are you handling your gloss black speakers without gloves?! That one is all fingerprinted!

Am I the only one uses automotive grade clear coat safe polish and doesn't handle his gloss speakers without white cotton gloves on..?

 

[skybertie]

Well, a couple things in my mind quickly. They are “effects” speakers but not only do they provide overhead sounds, they also phantom image with the bed layer. So you really don’t want to use just anything. You don’t have to spend tons, but good speakers are still good speakers.
The other thing, is if you’re trying component speakers. They’re made for very close proximity listening and I think would not last long.

I agree that you want good speakers for Front and centre... but have you had a look inside effect speakers at the typical driver used.. even ones sold by good companies? And have you turned off the front and centre channels and listened to the sounds that come from effects speakers during a typical film? I have an AV processor and separate amps so its easy for me to do this. "phantom image with the bed layer"... you mean have a depth of soundstage to make a sound come from further away than the speaker itself? Is your car sound system not capable of that? I guess I'm not seeing anything special in the specs quoted for an Atmos speaker and the text often seems to highlight the quality of the grille and its ability to blend in and hide the speaker! I'm more than happy to buy KEF reference speakers or better when appropriate....at the same time I begrudge being sold snake oil. My first degree is in Physics so I guess I tend to just cross out all the mumbo jumbo and look for the facts as I read adverts and articles. And when I see something being sold for £200 that looks like and specs like a £40 auto audio speaker I just pause....Like tyres you can't easily evaluate them until they are bought and fitted and by then its too late.