A cloud is the single most important acoustic treatment. Change my mind.

[manisandher]

My clouds...

 

[popej]

From speaker's view a MTM like D'Apolito or narrow but hight (Mid/)Tweeter (ribbon, AMT ...) may give reduced reflections from ground and ceiling.

Unless you lay MTM horizontally, which as stupid as popular

 

[CapMan]

Here’s mine

 

[tmtomh]

My clouds...

View attachment 312676

Those are really nice, and a very nice randomized arrangement too!

 

[manisandher]

Those are really nice, and a very nice randomized arrangement too!

Thanks. I put them up with the help of Stefan from KJF Audio here in the UK. Excellent guy and excellent service.

 

[Salt]

Unless you lay MTM horizontally, which as stupid as popular

Nope, would do the opposite.
MTM means narrow vertical with normal horizontal.
Tilted 90 degrees it does the opposite.

 

[fpitas]

Nope, would do the opposite.
MTM means narrow vertical with normal horizontal.
Tilted 90 degrees it does the opposite.

A lot of goofy MTM center speakers lie horizontally. Yes, it's a bad idea.

 

[Salt]

A lot of goofy MTM center speakers lie horizontally. Yes, it's a bad idea.

It's not that bad if one wants the center to beam right to the listener with low interference with L/R, though ignoring the ground an ceiling reflections of mainstream constructions with round tweeters.
With an, by directivity, appropriate mid/tweeter between mid/woofer like O-I-O could ease some (but not all) issues.

 

[Somafunk]

Here’s mine, GIK 242 panels fitted with GIK cloud brackets

 

[Weeb Labs]

It's not that bad if one wants the center to beam right to the listener with low interference with L/R

The trouble is that it does not simply beam; it produces a wide but heavily mangled horizontal response.

 

[fpitas]

Sheesh, when I hung ceiling acoustic panels, I had no idea they were called Clouds. They seem...classier now.

 

[Curvature]

John Brandt would agree. His studio designs follow the nonenvironment approach.

I have seen one study which says a highly absorptive ceiling is unnatural, especually when it is low height as well, and another which says that ceiling reflection is an important in producing envelopment (if the sound, as I understand, is decorrelated, which will not generally be the case in small rooms).

I'd like to clarify why Amir recommends using floor or ceiling absorption. It is because the early reflections may have FR significantly different from direct sound, which will have some effect on timbre.

IMO a proper ceiling cloud will be LF absorption biased and have significant diffusion. I don't know what would be the optimal mix of those things, though, and what other considerations would be important.

 

[dfuller]

I'd like to clarify why Amir recommends using floor or ceiling absorption. It is because the early reflections may have FR significantly different from direct sound, which will have some effect on timbre.

Correct. Namely, they have severe phase cancellation induced dips right where our hearing is most sensitive around crossover points in the 1-4k region.

IMO a proper ceiling cloud will be LF absorption biased and have significant diffusion. I don't know what would be the optimal mix of those things, though, and what other considerations would be important.

My opinion is that diffusion is generally only useful to break up a slap in a larger room without reducing higher frequency reverb times too much (i.e., making the room "dead"). And I agree, ideally you'd want a good amount of LF absorption to treat the most difficult modal issues... unfortunately, that requires more complex (i.e., pressure trap) absorption, or a lot of low density velocity absorption.

 

[Curvature]

Namely, they have severe phase cancellation induced dips right where our hearing is most sensitive around crossover points in the 1-4k region.

AFAIK our hearing is less acute between 1-2.5kHz because there you have a transition from phase-sensitive to level-sensitive hearing mechanisms.

Vanderkooy studied spectral dips and noted the crossover induced dips can be as deep as -12dB and not be overtly objectionable. This study was done in the 80s though and I don't know of anything as specific to loudspeakers and more definitive since then. Toole's work and citations seem to suggest these problems aren't very audible, either.

I disagree about the use of diffusers being limited to controlling slap echo. A diffuser can be fuzzily thought of as ranging from a flat surface, just as a reflector, and can be as complicated as those fractal phase grates we're used to seeing. The complex clouds I've seen combine various diffusive features.

Here's a cloud (hard to find good pictures) at one of the Aix Recordings studio rooms. I don't know the details of the construction.

I think there is as much complication about assessing diffusion effects as there is about speaker directivity. For example, this very rare 3D plots below.

R&D Stories: Acoustic Diffusion Research

This article offers a valuable inside perspective about developing new diffuser solutions, and lessons learned while designing countless critical listening rooms around the world. A journey that lead to the creation of the PolyFlex diffuser, which will scatter either horizontally or vertically...

audioxpress.com

My posts aren't very helpful in providing advice, but that genuinely expresses how I feel and what I've read about room acoustics. The firm advice and opinions tends to avoid complications.

 

[Absolute]

Before 4 inches of insulation and ecophon focus ceiling treatment and after in the whole living room;

 

[ernestcarl]

IMO a proper ceiling cloud will be LF absorption biased and have significant diffusion. I don't know what would be the optimal mix of those things, though, and what other considerations would be important.

My room is already quite "dead" so how about wrapping the insulation inside a plastic bag?



Yeah, probably not a "proper" ceiling "cloud".

First time using a hole saw drill bit where I broke two of the bits. This was not a very clean job... and I think I almost broke my wrist!

It definitely did improve objective measurements and decay time in the spectrograms by a small amount. However, because my ceiling is low (~7ft), it made my desk's "standing mode" setting (an adjustable standing desk) more uncomfortable to use -- I can reach the cloud with my fingertips -- not surprisingly, measurements when in standing mode also are now slightly worse.

 

[Pareto Pragmatic]

Since the OP asked for their mind to be changed.... I will be oppositional. Is there any height to width ratio for a room where you would say the ceiling is not the most important surface to treat?

I could think of other exceptions, but while they might fit the letter of this thread, they certainly would not be in the spirit.

I have never thought about the relative effects of sidewall versus ceiling first reflections. Now I wish I had an empty room, so I could compare untreated to sidewall first reflection only to ceiling first reflection only.

 

[fpitas]

IMO a proper ceiling cloud will be LF absorption biased and have significant diffusion.

I think you're right. I hung a bunch of 4" thick broadband acoustic panels about 5" from the ceiling, then covered the rest in foam diffusers. It passed the, "Friend listened and liked the results" test with flying colors

 

[ozzy9832001]

Given that almost all non-coaxial speakers have pretty nasty cancellations around the crossover(s), it stands to reason that fairly heavy absorption hanging from the ceiling to heavily reduce the ceiling ER is much more important than any side wall or rear wall treatment, regardless of horizontal directivity behavior. Even with coaxial designs, I'd consider it quite important.

It is immediately audible hanging a cloud in a room that has a reflective ceiling - everything gets "tighter" and the soundstage becomes much clearer and less fuzzy.

I disagree, but with the caveat that it's effectiveness will greatly depend on the room, the speakers and your listening position. Like all treatment options, throwing them around willy nilly will generally lead to more problems than it solves.

In my particular room, ceiling panels helped to cull a peak at 140hz. Moving those same panels to the front wall, smoothed out the response from 150hz all the way up to about 400hz.

 

[JohnnyNG]

If installing absorption on the ceiling isn't feasible, how about something right on top of the speaker and overhanging it? I'm picturing a 2" thick panel as wide as the speaker and overhanging 8" or so. In terms of the ceiling area/subtended angle the drivers "see", this should cover as much as quite a big ceiling panel. Depending on the speaker/drivers, of course.

Would that work?