In a conversation with Ian a little while back I found out that the M3 in-ceiling speakers were not totally transparent. To create a speaker flush with the ceiling required the speaker to be recessed behind the flange, and apparently, this gives enough clues for us to know where the sound is coming from. (note this is probably true for all in-ceiling speakers)

My first reaction was dismay … But thinking about it more I decided that in most cases you really should not care.

First let’s look at why anyone would care. If you are in the sweet spot of a decent stereo setup ... instruments and vocals should be coming from where the recording engineer placed them and not the obvious source (the speaker). Now with a conventional set of speakers you’d sit between them and typically somewhere around the same distance from the speakers as they are from each other to get this sound stage. Get too far left, right, close, or far and the stage will get muddied or collapse.

Now let us think for a minute about ceiling speakers. First off they are already compromised as they are … wait for it… on the ceiling. I’m really not that concerned with the sound stage coming from above as I am about not being in the same plane as the speakers are firing. Very rarely are you standing right below them. So right off the bat the speakers are not firing at you as they would if a pair was sitting on the floor. Next if one thinks about how far from the speakers our ears are … we are much closer to the ceiling than we would typically be from a stereo setup on the floor. For example if the ceiling speakers were 10’ apart and our ears were at 5’ the we’d need a 14+’ ceiling while standing directly below them to be in the middle of the sweet spot. If your ceiling is 8’ high you might be hard pressed to find a sweet spot if you were standing. So even if a ceiling speaker could image well in most cases you might not be able to take advantage of it …

Now, “does it matter?”

For background music, in your dinning room, hallway, or anywhere else your not going to be sitting consciously listening for the stage it’s not going to matter.

As a 5.1 or 7.1 surround speakers they are a poor substitute for any of the QS speakers (which give a field of sound you can not localize) but if aesthetics are an overriding factor it will probably do an ok job at giving you the surround effects. One might note that even if you could localize where it came from, while the movie is playing your concentration is elsewhere.

In an ATMOS system you’d like your speakers to image smoothly as objects fly around you but you are also limited by your ceiling height. So if you have high ceiling you might consider using the M3 in-wall or on-wall versions (which can be transparent). But for most of us with ceilings 9’ and under the in-ceilings would probably not be any worse.

The only other case I can think of is that these are your main speakers … in that case you ether don’t care about imaging or you made a very poor choice.

Bottom line ... if your creating a ATMOS theater and have 11' ceiling you might steer away from the in-ceilings. In all other cases they are probably be just fine.
Thoughts?

I have had an Atmos (7.1.4 with dual subs) setup for 3.5 years now. I have a ceiling that is below the desired Dolby spec at just under 8 feet tall. My only real option for good sound dispersion and coverage were to ceiling mount "on-wall" M3s using Axiom FMBs so that I could get the correct angle forward and back and be able to point the speakers towards the listening area. Works amazingly well and I've be in a good number of Atmos demo rooms at CEDIA since 2014 when Atmos was announced for home use.

Now, in-ceiling M3s have an aimable tweeter that helps to get better overhead imaging, but for really low ceilings, you still need the sound to be able to hit all of the seats, so to speak.

So in actuality, the further away the speaker, the more dispersion that it creates by the time it hits the listening area. The closer, then the less dispersion.

If in-ceiling speakers have a lower dispersion than regular or "surface mounted" like my on-walls, then you would actually want to only use them in high ceiling applications (ok, higher than my 7ft 10in ceiling, lol) as they would have enough sound dispersion at a lower ceiling distance.

Keep in mind that Atmos speakers are often referred to as "overhead speakers" when they should never truly be "overhead." They should be 35 - 50 degrees in front or behind the main listening area. That is why you wouldn't want something that is a tad more "laser focused" at those angles on a lower ceiling.


With all of that said, I have no idea as to the sound dispersion capabilities of Axiom in-ceiling speakers. If they are wide enough, the math may work out in one "lower ceiling" room vs another. For me, I had 2 reasons for going on-wall but mounted to my ceiling... 1) I have a lot of soundproofing technology in my room construction (and acoustical treatments, but those are movable). I would never be able to find locations for in-ceiling speakers that wouldn't hit a ceiling joist or hat channel or both that would fall within Dolby spec, even if I did, retro-fitting in-ceiling speakers would massively compromise my soundproofing. Additionally, I wanted the best Atmos sound I could get with Axiom speakers, so I needed a no-compromise approach with the speaker type and installation, that meant on-walls angled towards the MLP.

So that is what I did and it is outstanding.

Here is some additional information from an actual professional about angling speakers for lower ceilings due to Atmos dispersion requirements...
DOLBY ATMOS: DISPERSION REQUIREMENTS FOR CEILING SPEAKERS

An in-ceiling M3, installed 52" above the plane of the ears, projects a pristine disc of sound from its tweeter, onto that plane, that is 5 feet in diameter. So if you're sitting right under it, the area 2.5 feet all around you is getting illuminated with linear highs.

The sound actually projects much wider than that but it becomes less linear as you move further out.

The mids and lows project even more than the highs.

The diameter of the disc grows in direct proportion to the height of the M3. With 11 foot ceilings, the diameter is 10 feet.

Nick has an interesting point. Being able to aim your speaker when you have a low ceiling. I'm using a mix of height and top surround speakers in my setup*. The heights are M3 bookshelfs and the tops are M3 on-walls. I passed on the M3 ceiling speakers for a few reasons:

1) Wanted to be move them if needed. This included an option of being able to setup my screen on the long or short walls.
2) Didn't want to put a hole in my ceiling (like Nick ... there is a lot of expense which went into soundproofing).
3) Ability to aim the speakers (heights on a FMCB and I was not quite sure how I was mounting the tops but if Nick vouches for the FMB for the on-walls that may be the way to go).
4)Transparency was the only other reason but as my post states (I'm not sure it matters)



*The mix of heights and tops were carefully picked to work with ATMOS, DTS-X, and Auro-3D.

On-walls, I assume use the wall to reinforce the base frequencies. So, The FMB mounting of on-walls leads to some questions ...

1) is that assumption correct
2) how far from the wall can one get before you hear a difference
3) Is the distance of an FMB ok?
4) Does tilting it in various directions change the sound ...

You also need to be concerned with driver center line to side wall distance, driver center to floor distance, cabinet baffle width and the dimensions of your room. Just sayin' that the response of speaker boundary interference is more complex than just the distance of the FMB.

Then you also have floor and ceiling bounce. LOL!

And multiple drivers to contend with in all these speakers. Time to give up and just listen.

mojo you are confusing the issue. I’m asking at a simple question on mounting a on wall speaker. Your multiple posts are the equivalent of spam and are not helpful.

It's not a simple question as I've pointed out.

Should I be concerned (what are the acoustic issues related to) with mounting M3 on-walls with Full metal brackets?

You should not be concerned. I expect them to sound much better than regular M3s that are mounted on FMBs placed close to a wall surface. The wall-mounts are bottom-ported and moving them slightly off the wall or ceiling won't make an appreciable difference in what you will hear.

Thanks Mojo. That is the answer I’m hoping for.

Just thought some feedback and opinions might be worth while.before I went though the expense and trouble to try it.

The FMB have been designed very well with the distance they place the speakers off wall. The port reflections are actually quite minimal. The ability to aim at you will also greatly improve immersion. Especially if perfect placement isn't ideal or possible.

The on wall will not have as much low end due to cabinet. To which most people that have heard ATMOS with larger drivers highly recommend something with low end if possible.

Hopefully helps a little

Yeah. I agree with Brendo. Put an M100 on your ceiling, Rich.

Mojo, if anyone blazes the ceiling mounted M100 trail it's going to be you. Please send pictures.

Ahahaha. I'll bet it's been done. The M100 comes in an on-wall version likely with slotted ports all around its perimeter to mimic the glorious full-size sphincters of the floor-standing version.

Actually, I’d believe it if someone did an on-wall M5.

Would you believe this?

https://drive.google.com/file/d/1-TizQ4ypPwvuIayKptweFyzU8tSdhSBn/view?usp=drivesdk

Here's a better shot.

https://drive.google.com/file/d/1-_pG_Rzpd1uKUPh04Ky8bcP05oX43Kqn/view?usp=drivesdk

These stacked configurations are soooooo good. Unfortunately the ADA-1000 can't adequately power this M50/M5 monster on some peaks. The 1000 is great with M50, M3, M100 and very likely M60 and M80. The M5s are very power hungry.

Even though the 1000 is crapping out, it's still managing to hit a clean 106dBC nine feet away.

I’m sure a little photoshop would be easier and more convincing.
P.S. love the analog meter

I used that meter to buy dress shoes once. I told the sales lady I was testing for genuine leather. She looked at me like her brain stopped working.

I precariously stacked the M3 on top of that mess. It didn't sound good. I'm back to the M50 by candle light and sarsaparilla. I could listen to The Notting Hillbillies on the M50 all night!

So, I’m concluding that the M3 ceilings best fit where aesthetics are of overriding importance (no surprise there).

Best used for background music in rooms like your dinning room where you don’t want a sound stage (wonder if QSx’s would work better sound wise, as a background speaker, with a more even fill in some rooms)

Or as an effect speaker where the aesthetics of QSx, M3, or M3 on-walls don’t work (all the talk about dispersion, directivity, transparency and fixed placement make the latter better options)

The QS10s are excellent for background music. I have tried them in multi-channel stereo with all other channels off and was surprised to discover how well they sounded.

This brings up an interesting point. I have the M50s in my living room for casual listening. What I mean by that is I am listening while reading or writing or thinking or looking out the window making fun of the people outside. I find however that I am constantly drawn into the performance so casual listening becomes serious listening. And that's not good.

So yeah...I continue to be quite upset with Axiom for making speakers that are so involving. Last night for example, after howling at the full moon by the fire, I came in to do some reading with background music on and quickly found myself listening to the M50s. I don't have that problem with any other speakers.

So I'm thinking maybe I should ditch the involving performance the M50s create in my living room in favour of an Air N3 or maybe QS10s.

hmmm .... wonder what the people outside are thinking ...

I live here so that I may be entertained by the humanoids outside my house. As for thinking, I'm not sure they've learned how to do that yet.

I'm going to apologize beforehand for saying this but I can’t help myself ... That’s exactly what that monkey said at the zoo the other day ...

That was me!

It is interesting how the family-of-curves works. We hear the total radiated sound power no matter our position in the relation to the speaker. This means even if you are directly on axis to a speaker that is inset behind the wall (or ceiling) plane you will still hear the problems this creates. In a double-blind listen test the results are not subtle, it is a resounding win for the speaker that is proud of this plane. So it really comes down to what the aesthetics are worth to you in any given room. Any of our in-walls mounted in the ceiling will outperform our in-ceiling but the grille will stick out a bit more.

Ian, how much can I pay you to build me some M3 in-ceilings that ARE proud-of-plane? Would be amazing if I could swap those in for my current M3 in-ceilings. Sadly, my wife would never tolerate square boxes on the ceiling.

BMan, I went thought the same line of reasoning ...

in the end I'm not sure that you'd gain that much if the in-ceiling were more transparent

I think you'd gain a lot more if you were able to aim the whole speaker ... Although a bit more of a high tech theater look ... I actually think Nick Buol's M3 on-walls are a pretty good look considering how low his ceilings are.

The M3 In-Wall may make sense ... I held this up to my ceiling and they do not look too bad (I'm thinking of doing that in our kitchen). Also, I believe Axiom is looking at ways of extending the grill to cover it's surrounding frame ... no guarantees though.

You may be right. As it is, overhead usage seems to be on the conservative side in most movies (atmosphere, rather than discrete sounds).

I have the newer in-ceiling M3 grilles that cover the full speaker, and quite like them.

https://photos.app.goo.gl/ARdv2Fd7Vet2FYRFA

FYI that in my room I got the paintable on-wall M3s and painted them the same darker color of my ceiling so that they don't visually stand out too much. Helps a lot to make them not distracting.

It's been a long time but I think you are the proprietor of Starlight theatre, correct? I seem to recall it is pretty cool.

Correct.

I had a lengthy build thread here with lots of pictures and videos, but my web hosting site gave me large amounts of grief earlier this year about having a large amount of pictures stored there that weren't directly linked to my web page. I was using the "site" as a storage spot for my theater build, other hobbies' photos, and a LOT of movie poster image storage as I do graphics/image work for DIY acoustical panels with custom printed fabric. Anyway, there was just way too much to recover and too many links to update when I told them "good bye." The video links in the thread here should still be good, but I don't think that anything has been updated with the latest tweaks for some time.

I need some more panels. Wish Serenity was still around to trade wine for panels.