In Ceiling Speakers for 400 sq. ft. home theater recommendations (size and dispersion) for Atmos

[FriedChicken]

Losing my mind here.

I have a 400 sq. foot home theater (23 ft x 17 ft x 8 ft ceilings).


I currently have a 7.2 setup with RTi10 front towers, RtiA3 surrounds and polk something else rear surrounds (CSi A6 center).

I'm going to have someone put blow-in insulation into the attic, before then I have to take care of *any and all* attic work, present and future.

I've gone deep, and am looking for recommendations in the $500 to $700 for in-ceiling speakers. My main concern has to do with the dispersion pattern, opening up the pandora's box of downfiring vs directional speakers.

Dolby has this to say:

Characteristics
Dolby Atmos audio is mixed using discrete, full-range audio objects that may move
around anywhere in three-dimensional space. With this in mind, overhead speakers
should complement the frequency response, output, and power-handling capabilities
of the listener-level speakers. Choose overhead speakers that are timbre matched as
closely as possible to the primary listener-level speakers. Overhead speakers with a
wide dispersion pattern are desirable for use in a Dolby Atmos system. This will
ensure the closest replication of the cinematic environment, where overhead
speakers are placed high above the listeners.

Mounting considerations
If the chosen overhead speakers have a wide dispersion pattern (approximately 45
degrees from the acoustical reference axis over the audio band from 100 Hz to 10
kHz or wider), then speakers may be mounted facing directly downward. For
speakers with narrower dispersion patterns, those with aimable or angled elements
should be angled toward the primary listening position.

source

45° dispersion seems relatively low, but published numbers are difficult to find.

Regarding Timbre Matching, I found these options:

1. Polk Audio RC80i
2. Polk Audio 90-RT
3. Polk Audio V Series V80

The RC80i used to be $150 for the pair but are now $250 for the pair (angry noises).
The 90-RT are $300 each
The v80 are also $300 each.

The Klipsch CDT-5800-C II were $400 each and are now $150 each. Go figure

Please help, I just closed about 30 browser windows of speakers. I will build a backbox for whatever speaker I decide to get.

 

[Triliza]

I don't have any recommendations for you, but I doubt timbre matching will be a real issue for a home theater's in-ceiling. In case you haven't seen it, there are some general info about the topic at Audioholic, although you seem to have done your research and are looking for speakers suggestions, Amir has reviewed a couple of them, have you seen them?

 

[FriedChicken]

I don't have any recommendations for you, but I doubt timbre matching will be a real issue for a home theater's in-ceiling. In case you haven't seen it, there are some general info about the topic at Audioholic, although you seem to have done your research and are looking for speakers suggestions, Amir has reviewed a couple of them, have you seen them?

I have, but they were out of my price range and he didn't like any of them.

The audioholics article you referenced doesn't speak about timbre matching. I imagine timbre matching can make quite a difference as audio "travels" from one speaker to the next.

 

[Triliza]

I have, but they were out of my price range and he didn't like any of them.

The audioholics article you referenced doesn't speak about timbre matching. I imagine timbre matching can make quite a difference as audio "travels" from one speaker to the next.

It doesn't hurt to have speakers from the same line, and all Polk speakers reviews I have seen so far have been quite good, so getting one of the models you mentioned may be your safest bet. I'm still not sure you'll be able to tell the difference about timbre if you use other speakers from other brands, how much and what kind of information is played by atmos speakers, but I may be mistaken, maybe someone else can enlighten us with their experience.

 

[Triliza]

It seems not many people have in-ceiling installed in their setup, and you seem to be in a hurry. I searched the forum (you may have done the same already) for Polk in-ceilings and came up with the one below, not really much, try to pm the people that have Polk in-ceiling for their impressions:

https://www.audiosciencereview.com/...-audio-rc80i-2-way-in-ceiling-speakers.30375/

https://www.audiosciencereview.com/forum/index.php?threads/in-ceiling-speakers.39703/

https://www.audiosciencereview.com/...ling-speaker-review.42029/page-3#post-1486613
(below this post Amir offered to split the cost with someone so he would test it, don't think anyone took the offer)

 

[FriedChicken]

Sonance publishes backbox diagrams:

Visual Performance Series Acoustic Enclosures

www.sonance.com

Medium = 6", Large = 8" for their in-ceiling speakers.

With the speakers being available at bestbuy for good prices. It's questionable how they sound though.

In-ceiling speakers *should* be infinite-baffle, but it's hard to find information on whether or not this is true.

 

[BJL]

I have, but they were out of my price range and he didn't like any of them.

The audioholics article you referenced doesn't speak about timbre matching. I imagine timbre matching can make quite a difference as audio "travels" from one speaker to the next.

I use one brand of speakers ear level, and another for height speakers (although they are not in ceiling). I have found that room correction/speaker eq does a fine job of getting timbre, level, and timing correction & matching, for all practical purposes. I use Dirac Live, but I presume the other major software systems will also work.

 

[FriedChicken]

I was dead set on the Polk Audio V60 or VT60, but then I looked here:

Dolby Atmos: Dispersion Requirements for Ceiling Speakers

In this blog article we look at the dispersion requirements for ceiling speakers in a Dolby Atmos system. We consider the example of a system with 4 ceiling speakers and two seating rows and show how dispersion requirements change for: Speakers firing straight down vs. angled at the listening...

acousticfrontiers.com

Given the low 8' ceiling, whatever speakers I end up getting will need angling capabilities or have a very wide dispersion pattern.

 

[Dal1as]

Do not use non angled down firing in ceiling speakers. Atmos is all about the angles and proper separation between speakers especially between the bed layer and top speakers.

I haven't seen this gone over much here. I won't link it as I am not sure if it is allowed but AVS forums has a thread with recommended angled in ceilings. There are also multiple threads about the angle aspect there.

Matching the speakers isn't really needed.

The RSL in ceiling speakers are highly regarded. If WAF isn't a factor angled on ceiling speakers like mounted bookshelves or outdoor speakers are generally better.

 

[FriedChicken]

Matching the speakers isn't really needed.

Qualify this statement. This contradicts common knowledge and what dolby explicitly states.

 

[Dal1as]

Qualify this statement. This contradicts common knowledge and what dolby explicitly states.

It was in reference to the speakers the op picked to timbre match not so much against the good practice of doing so. It was written hastily and too vague. My bad as I had planned on following up.

Firstly. Matching speakers is much more than matching just a brand. The only way to truly match tonality is to use the exact same monitor in every position and also eq each channel. Not to mention treatment to account for boundary affects. 90% of the people in this hobby are unable or unlikely to do this.

Even speakers within the same model range will sound different.

Same with location. A speaker near multiple boundaries will sound much different than the same speaker near the middle of a wall.

There is also the fact our ears and brain do not process sound well from behind or above.

Best practice is to use the same speaker in every position but how many people do that?

Timbre matching by brand especially becomes a crapshoot as all the speakers will sound different in the vocal range which is most noticable. Using speakers with the same tweeter helps but is not enough.

 

[Ellebob]

Working as a calibrator in this industry I can recommend a few things. While mismatching speakers won't sound bad it is never as seamless with panning between speakers as speakers that are more closely matched. If you ever get a chance to compare this you will hear the difference. Again, mismatched speakers will not be bad.

That being said in your situation I would mismatch you ceiling speakers. Dolby's home and pro recommendations differ and they don't practice what they preach in their home demo rooms as they angle their speakers. I would look for angled speakers that aim at your listening area. Their are many measurements to back this up on this site and others. Look at what speakers measure 45 degrees off axis.

A good off axis response is a speakers that from about 500-100hz and higher will start to have a downward slope and the mid and high frequencies will be decreased. But the overall response besides the downsloping will look similar to the on axis. A poor off axis will start to have some dips not seem in the on axis.

Often at 45 degrees the off axis can be down 10db or roughly half volume of the mids and highs. This is very noticeable, turn your current speakers 45 degrees away from you and you will hear the difference. The speakers when used in this manner will not be close to being matched in timbre. Acoustics 101 is speakers sound better when they aim at the listeners. I'm on my phone at the moment or I would post a picture of one of Dolby's demo rooms where they have bookshelf speakers mounted on the ceiling aimed towards the listeners, why didn't they just aim them straight down? Because they know it is better if aimed at the listeners and what they teach in their classes and pro documentation.

So onto recommendations. Look for speakers that angle at least 30 degrees and preferably 45 degrees especially if you have two rows. Getting good coverage for Atmos is difficult with 2 rows of seating in most homes with standard 8' ceilings is difficult. You will often have to place speakers at 30 degrees in front of you with speakers that angle 45 degrees that way both rows will still be in a decent cone of sound.

Avoid speakers that aim straight down, angle only 15 degrees and skip pivoting tweeters designs. There are many companies that make angled speakers but her are some. Paradigm, Triad, Elac, Monoprice, Golden Ear, Def Tech, JBL, Revel and many more.

 

[FriedChicken]

It looks like Polk Audio is then out. Their ceiling speakers don't angle much if at all. Klipsch has an offering (CDT-5650 and CDT-5800) where the woofer angles 15° and the tweeter more than that. It's better than nothing, but not the full 45° you're suggesting.

I don't like designs where the tweeter comes out of the middle of the woofer. I feel like valuable driver space is being taken up. What's your take on 8" vs 6.5"?

 

[FriedChicken]

It does look like the Polk AUdio 80F/X-RT might offer what I want. The angle isn't listed, and the tweeters look like they're at weird angles pointed away from the listener? What? Polk says they're not recommended for Atmos installation, but that they are matched to the RTI line.

https://i.postimg.cc/WTLCStNj/g10780-FXRT-o-right.jpg

 

[FriedChicken]

Also the Yamaha NS-IW280C

NS-IW280C - Specs - Yamaha - United States

Easy-to-install, versatile in-ceiling speaker system delivers high-quality natural sound. Tilted woofer design for optimal sound directing to listening position.

usa.yamaha.com

 

[FriedChicken]

I just ordered four Klipsch CDT-5650-C II from amazon "used like new".

Hoping for the best.

 

[Ellebob]

8in vs 6in typically comes down to bass extension, volume capability and distortion. The 8in is usually superior but when crossed over using a sub and not run full range the difference is not as much.

 

[FriedChicken]

8in vs 6in typically comes down to bass extension, volume capability and distortion. The 8in is usually superior but when crossed over using a sub and not run full range the difference is not as much.

I've heard differing opinions on this: that the 8" is unnecessary, will simply overdrive the receiver, and ultimately isn't recommended.
I could still return the ones I got... Would you go for an 8" instead of a 6.5"

 

[Ellebob]

Short answer...If you like to play loud then go with 8 inch.

8 inch isn't necessarily harder to power than 6 inch and can be easier. A lot of variables and specs don't tell the whole story but by spec the 8 inch plays 95db with 1 watt of power and the 6.5 inch plays 94db so the 8" can play louder with the same power meaning it is less strain on the amp.

In reality you would want to look at an impedance graph of both to see the differences on which would cause more strain on the amp. I imagine their negligible and most receivers will power either just fine.

When you look at a lot of graphs on this site and look at same series of speakers what you typically see is the 8 inch version of the speaker will have less distortion as you play louder. At moderate volumes they are probably similar. So, if you like loud this is the reason to 8 inch is to keep everything cleaner as you turn it up.

 

[FriedChicken]

I went with 6.5" after debating about it. I just got them installed (not wired). The significant motivators were 1. the low ceiling, 2. the size of the cutout.

I was going to build a backbox, but I'm glad I decided against it after seeing the work involved, and 2 the realization that the attic space above serves as an infinite baffle.