Does the first reflection point actually matter??


Hello my friends,

So please read the whole post before commenting. The question is nuanced.

First, as you probably know I’m a huge fan of the well treated room, and a fan boy of GIK acoustics as a result, so what I am _not_ arguing is against proper room treatment. I remember many years ago, perhaps in Audio magazine (dating myself?) the concept of treating the first reflection points came up, and it seems really logical, and quickly adopted. Mirrors, flashlights and lasers and paying the neighbor’s kid (because we don’t have real friends) to come and hold them while marking the wall became common.

However!! In my experience, I have not actually been able to tell the difference between panels on and off that first reflection point. Of course, I can hear the difference between panels and not, but after all these years, I want to ask if any of you personally know that the first reflection point really matters more than other similar locations. Were we scammed? By knowing I mean, did you experiment? Did you find it the night and day difference that was uttered, or was it a subtle thing, and if those panels were moved 6" off, would you hear it?


Best,


Erik
erik_squires
Yes Dennis Foley is someone that understands room acoustics and how to treat a room.

I never found treating first reflection points to make any difference. Then again with my box speakers I toed them in 45 degrees per the manufacturers recommendation. FWIW, in my experience treating the ceiling and upper room corners made the biggest difference.

With my Analysis Audio, Quad 57, and Acoustat Model 2s I made some very simple 24 x 48 panels with thin foam and placed them on the back wall. They don't need to absorb much, just upper frequencies and they do the job just fine.

@jrwaudio, if your couch is up against a wall have you tried an absorption panel on the wall behind the couch. I found it helpful when my couch had to be in the same position.
@tuberollin


You are clearly wrong .... :)  I'm joking, making fun of so many people here who can't see past their agenda.  Your experiment seems to be exactly the kind of thing I'm asking.

Seriously though, what speakers are you using?? and exactly how do you feel the difference is?? 
In my experiences the closer it is to the source and the more reflective it is, the more it matters. It adds a bit on non specificity or for lack of a better word phase blurr ( like an out of phase tweeter) 
The most important part is getting to critical mass in absorption, and adding diffusion in the right areas. The laser-line, first reflection points, in my mind, have never born fruit.
I think you are right...

A room is so complex acoustically that it takes our ears to make it beautifully musical not only equations...First point reflections and other measurements make sense in a completely acoustically dedicated engineered ideal room...In normal irregularly and non ideally shaped room with furniture and non dedicated walls, with varied content materials being books, cd or whatever, it takes more than passive materials treatment of first reflection point by the book... :)

A passive room treatment with some balance between absorption and diffusion will do but cannot resolve all the room/speakers topology/location and content problems without speaking about the specificity of each audio system....

I was happy when i begin to create in my dedicated room non electronical ACTIVE room controls with interlinked active and passive resonators of different type all connected to 10 cheap Schumann generators grid...

Imaging, dynamic, soundstage, all is very good now, and a separation of the musical image from the speakers is possible ....

What most people dont realize is that nearfield listening is affected very much by the room acoustic...It is a myth to say that with near listening we are free from the room acoustic...But we cannot know what is missing if we have never experience it in the first place...

I know i listen near field (3feet) and in a more regular position (8 feet) and the sound is so good in my 2 positions that i dont prefer one to another.... Complete different experience with one thing in common : an encompassing soundstage (near listening) or a soundstage free from the speakers location (regular listening) in the 2 cases the sound dont come from the speakers...

And it is a myth to think that tonal accuracy can be separated complety from imaging...This 2 different qualities are ALWAYS related to one another through the acoutical performance of the room...

All my devices and materials are homemade and are very low costs by the way.....i incrementally add something one day after the other for the passive room treatment...Same thing for the more complex creation of the active controls....

Being audiophile is only remembering his listening history  and using it like a tool....



Mahgister,
Please make case for how front ported bookshelf speakers are impacted by room acoustics while listening to them in the near field? 3-4 feet. I don't think my ears are that good. Joe
Mahgister,
Please make case for how front ported bookshelf speakers are impacted by room acoustics while listening to them in the near field? 3-4 feet. I don’t think my ears are that good. Joe
What i just said has nothing to do with my alleged hearing accuracy.... I am not a bat first point...

Second point i know what i speak about because modifications of the room acoustic change the imaging and even the tonal timbre perception, i know it by EXPERIENCE....

Between nearfield and regular listening there is ONLY a degree of variation of the relation, NEVER a complete separation, between the direct waves and the indirect one and their synchronisation.... What we perceive is always a reconstructed "informed wave", that is the sum of these 2, by the brain Fourier analyser... By the way my active controls resonators grids act also like some fixed beacons through these flowing waves helping the brain to recover the information and recreate it from the resulting complex waves of the room coming from many obstructions and devices....Nobody listen only to direct wave in a room nevermind where you seat.......

There is NO case for arguing with experiments and experience....You ears are probably better than mine i am 69 years old but i hear very well for my age, my ears are informed by my listenings history... :)

By the way what i speak about is new, because nobody or almost no one speak about active non electronic acoustical device controls( active or passive linked resonators connected to modified Schumann generator)...

:)

« There is sound in my ears even in a silent room...There is also a pair of ears in the sound wave body» -Groucho Marx

«This is only the blood waving, or silence listening to itself» -Harpo Marx
maghister said:  
And it is a myth to think that tonal accuracy can be separated complety from imaging..


I definitely agree with that. I've had my perception of image depth and  spaciousness explode just by tweaking equalizer settings. 
Thanks for that pointer tuberollin.
I tried what you did, moved my front sidewall 244's back about a foot, leaving the 1st wall reflection point slightly off to the front of the panel. I observed similar results, a little broadening of the soundstage side wise and a little more clarity. I will try it for awhile, see how I like it with most records, but with my go to test album I like it. It's like the little tiny bit of reflection I get from those two spots opened up the sound a tat but without making it overly bright.
I think the best answer is it depends on all the different factors that go into system/room interaction, so whatever sounds best is the right approach.  For me the answer was yes indeed, here's the whole story - 

My room treatment journey started with getting a package of Aurelex foam, the knobby kind, 2" thick, in 2' by 2' panels, which I attached to some simple cheap DIY wood stands, such that the foam was roughly at the same vertical position as I would put acoustic absorption panels.  I moved these around the room,listening and moving, and found that indeed the best sounding spots were at the 1st refection points and also almost exactly behind me, but about a foot apart.  I got GIK panels for the side refection points but left the stands behind my due to the closet behind them.  This was a very nice start in a series of improvements, which I guess actually began when I got rid of the coffee table in front of my listening chair (amateur mistake) and perfecting the speaker placement and toe-in (Cardas method).  At this point I had heavy curtains over the window on the front wall, and furniture in the front corners acting as diffusers.  I already had a heavy carpet, and wanted to also try the first reflection point on the ceiling but would have had to part with the ceiling fan, so that was a non-starter.  Then I decided to experiment with the front of the room, started by getting rid of the rack and put the gear on the floor and used simple thick pieces of wood and some cheap cones etc to decouple them from the floor.  That was a also a nice improvement, not as noticeable as the absorption on the sidewalls but still good.  Then I started to experiment with diffusion on the front wall bc that's what is recommended and looks pretty cool too.  At first this seemed pretty good but after living with it for a while, I decided to go back to the heavy curtains just to hear what would happen and WOW things sounded much better on the third part of this very long A-B-A test - clarity and tone and dynamics were all improved.  Curtains are staying.  I don't know why the diffusion originally sounded better, maybe it just sounded different and going back and forth was a real pain so I never bothered with quick A-B-A tests like I have done with other things. I imagine that like with gear I will continue to experiment, all part of the journey.  Somewhere in there I also changed my chair which I think can also make a big difference.

Btw my room is a bit of a tunnel (11.5'W x 20'L x 8.5'H) with front wall being 8.5'W, and I have box speakers with a reputation for brightness.  I'm sure those factors have a big influence on the impact of room treatments.

Curious if anyone has tried to use a good headphone setup as a reference for no room interaction, and treated their room until it sounds closest to the headphones?


Not exactly on point, but close 

For those of you who want to have the greatest clarity from your speakers and have decided to put 1st point reflection killers on the outer sides of your speakers already, try putting an identical pair on the inside of your speakers. This will effectively give you as sharp/clear signal as you will ever get. If you want that kind of signal - If you have no wife - If your not anal about the physical appearance.  

Many years ago I had a product called Echo Muffs which was, in essence a 5' high U shaped heavy latex pad wrapped around and close the sides and rear of the speaker and projecting forward about 6 inches in front of the speaker. Boy, did it work! Sort of like a poor man's LE/DE room.
Then I got married! :-)
Speakers that can lean towards bright will sound less sibilant with the first reflection points treated if you can’t place them as far from the sidewall as your listening chair.
I am using Stillpoints Aperture 2's at first reflection point but they really clicked into place when I added another set of Apertures in the center, between the speakers that is.

ozzy
Personally I never quite understood the idea of the "first reflection point", but simply deferred to popular opinion. If speakers generate sound in a cone-shaped pattern in both horizontal and vertical planes, then why is the first reflection on the adjacent wall any more impactful on SQ than the first reflection point anywhere along the edge of the sound wave.
Because acoustic equations ask for some origin point in space and time...

But sound is not reducible to physical linear waves equations only, like many other phenomenon....

« The ears speak» -Groucho Marx

then why is the first reflection on the adjacent wall any more impactful on SQ than the first reflection point anywhere along the edge of the sound wave.
Because of the timing aspect.....

But i created my room acoustic without being slave to  an equation, on the contrary not obeying to the sound wave, i decide to command to the sound wave... This is active device controls of the room....
I used a lot of formulas but a simple one that gets you 'good enough' to start from is 1/5 from the sides walls and 1/5 from the back wall.  I got best imaging closer to the back wall and a little further from the side walls. Start with best speaker/audio rack placement and no acoustic support...get the best sound and then move on to the surfaces.
@tony1954, we are more sensitive to localization clues in the horizontal plane.  Most of us have our ears mounted on the side of our head, not the tops and bottoms.  :)   So early reflection points on the side wall tends to be most impactful,  Back walls that are close to the main listening position can also be more impactful in terms of confusing localization clues.  In certain cases where a room is very wide or where the main listening position is well removed from the rear wall, floor and ceiling can be more impactful.  Conventional wisdom is that you would like to have all reflections arriving at the ear with a delay of 5 to 20 milliseconds down 20 dB relative to the direct signal.  Reflections arriving at the ear within that window tend to smear the localization clues provided by the direct signal.  Reflections earlier than 5 ms tend to merge well with the direct signal, and those reflections arriving later than 20 milliseconds tend to be perceived as separate echos adding to the spaciousness of the room. 
@gs5556 ....the Yarlung site was a fun listen with my diy Walsh, which already project a large soundstage by themselves. *S*

'Sonic holography' took me back to when I owned a Carver C9 Sonic Holography Generator back in the '80s'....It didn't work consistently with everything; whether this was due to the mixing, the format, my space and placement within....

....but, when it did....you almost felt you could grab the neck of the lead guitar...;)

1st reflection with omnis (or, for that matter, dipoles) becomes either a moot point or the 'sticky wicket'.  When 'all', or nearly, becomes reflection the room becomes part of your 'system'.  It can't be ignored.

My current space is so ghastly that all I can do is to reference the late Linkwitz and 'ignore the room'.  This consists of running 5.1; F & R, L & R, with a sub 'up front'.  Works best with 4 identical drivers in the corners....

I can add a slight delay to the back pair which can enhance, but it becomes 'selection dependent' and a PIA to do. *L*

But then I'm 'listening to the stuff' rather than 'listening to the music', which kinda defeats the goal of it all....and I'm pretty atypical in approach, anyway....

Best, J
Funny....Yarlung states their generator fits a 2U rack space.

Which is just about the size of the Carver units.....🤔

...and I've got room for 2 of them....;)

*Familiar opening music passage....*

"Space.....The Final Frontier....."

...some will say I'm 'spaced' enough already....*LOL*

If I recall...Richard Hardesty’s white papers claimed that first reflections from side walls are the most harming due to confusing the brain as far as timing.
reflections off the floor result in excessive brightness and reflections off the ceiling don’t affect anything at all.
in my case, the room leans towards bare and lacks treatment but I don’t find the resulting sound overly bright. Nor do I have a problem with bass boom.  It did take quite a bit of experimentation with speaker placement to get here. 
Erik, here’s a test: if you could swivel deadening/diffusion panels at first reflection point so they are not parallel to the wall they are mounted on....say 15-20 degrees ( closest side to speaker 4” off the wall and side closest to listener touching the wall) this should throw the reflection to the back of the room, away from normal listening positions in the middle of the room, would this mimic the openness of a staged hall? Sucking the sound out and around?

@jacksky, your summary of the relative importance of the various surfaces that may provide early reflections is dead on, as is your recommendation regarding angling side wall first reflection treatments.  If you look at my post above, that is exactly the approach I used in my room.  The difference is that I used a solid oak 5' tall fully loaded CD rack instead of an acoustic panel or diffusor.  The side of the rack closest to the speaker is about 8" wide, and that side is spaced about 3" away from the wall.  The front edge of the rack is located a few inches behind the center of the 1st reflection point.  Some of the first reflection is directed behind the CD rack, some of it is reflected back to the front of the room, and some of it has its reflection trajectory changed so that it no longer is aimed at the main listening position.  I figure that wavelengths longer than 1500 Hz are probably impacted by this arrangement.  I have an identical CD rack located in the same position on the right and left walls.  These racks are much more effective than full range GIK monster or soffit traps for this purpose.   My room is 14' wide, so dealing with FRP from the side walls is imperative.  This gives superb imaging in my room.  Great depth and width, great center fill, nice life size vocal and instrumental size.  Best imaging by far I have ever heard in a narrow room. 
«Reflections within listening rooms are real and numerous. Some would argue that they all are problems to be eliminated. Others take a more philosophical view that they just provide information about the room, and the brain can figure it out. I’m somewhere in the middle, but leaning towards the latter. The science that has been done so far seems to be on my side.»

These words are from Dr, Floyd Toole one of the foremost acoustician in the world in an article written 1 year ago....

https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation

Secondary reflections plays an active POSITIVE part in a small room and contrary to some sayings not a necessarily negative one at all if we learn  how to use them.... Then the Active acoustical controls with a grid of resonators of different kind can play an important role in the way we use the complex interplay between direct sound and reflections.... Passive materials treatment is not enough contrary of what is said in most audio thread..... This is my last discovery....



My conclusion after my set set of experiments in the last 2 years, with my own devices, is that audio thread instead of being forums about the marketing of new designed electronic components should rather be for more than half of their content about acoustic and it will be better for this hobby....

No speakers can speak itself out of any room and without a room, and more than that, each speakers speak different languages in different rooms...

Most peoples cannot afford dedicated room, and dont want to "work" after paying big money for their basic electronic components, that is the crux of the problem for audio forums...But this dont erase the truth in audio:

Dont upgrade anything before embedding everything right...

Acoustical embedding is the most impactful one, especially if the other two has been taken care of....Acoustical active embeddings can transform most good audio system to a complete new level....


:)
I will add that owning a small room can be a very good thing because it is more easy to use secondary reflections with a usable time synchronisation to work with...

Near listening dont eliminate the problem of the room at all contrary to a common misunderstanding...

Near listening is affected by the room presence or absence of controls almost at the same extent that regular listening position, only a bit less, then the false idea that near listening free the listener of the acoustical impact of the room comes from that erroneous impression...I speak here about small room where device like resonators can be very useful to controls sound....Big musical hall are another problem completely...

« Refracted waves all the way down are good and reverberations delicious»- Bat proverb

«My body hear better when i make love»-Groucho Marx

« Planets also hear better in that case, it is because of others body proximity brother»-Harpo Marx
I own gradient 1.3 speakers  the speaker is all about the first reflective point , they don’t look like any other speaker . The inner ear site explains them. I have them in my system for 25 years , 

Reflections within listening rooms are real and numerous. Some would argue that they all are problems to be eliminated. Others take a more philosophical view that they just provide information about the room, and the brain can figure it out. I’m somewhere in the middle, but leaning towards the latter. The science that has been done so far seems to be on my side.


article: Room Reflections & Human Adaptation for Small Room Acoustics by Floyd Toole

Dr. Floyd Toole says that in 2019 article has impressive business and academic credentials, having held the postion of Corporate Vice President – Acoustical Engineering at Harman International from 1991 until he retired in 2007 and Senior Research Officer in the Acoustics and Signal Processing Group at the National Research Council of Canada.

He knows perhaps what he is speaking about...

My own experiments with my room acoustic, using reflections instead of killing them, make me think that he is right....I just stumble on this article few days ago, searching for a confirmation of my experiments that contradict many advices given on most audio thread....

It is not new, on many thread people advise to upgrade gear even without having ever embed it rightfully before... 


:)
I have diffusers at first reflection points on side walls and ceilings. Definitely helps !!!
I like Toole, but let's be clear that this is his personal opinion about what he likes.  For some of us, the acoustics of live spaces can take a toll on our brain power. As others have written, filtering out a room all the time can be exhausting, including academic settings.

I personally want my room a little less present.  I like my stereo to be the acoustic equivalent of looking across a mountain range.  That feeling of relaxation you get when suddenly you feel like you can see forever, but with my ears.

How much you are taxed by the space, how much you are willing to filter out is very individualized.  I think it's funny to do the recording experiment, where you tape yourself speaking in a room, and then play it back.  In the recording you become aware of the room acoustics, and then realize that you can hear them, you've just been filtering them out.  Fun stuff.


Best,

Erik
"It pays to keep an open mind, but not so open your brains fall out." - Carl Sagan.

One can also apply that concept to tuning ones' listening area.  It's possible to correct Everything....but you couldn't live in it.

But your significant other will demand that you do...Now.

Erics' 'mountain range concept' has appeal; the space 'gets out of the way' of the audible 'view'.  I like that...+1, at least... ;)
Hi Erik, there is a lot of well meaning advice being offered but most of it ill informed. This whole thing is a science with specific goals. Some posters claim that they adjust the toe-in of their speakers and everything sounds fine. Useless info this.

Correct treatment is truly transformative and if you are not prepared, for less than the cost of a mid-priced interconnect, to buy a suitable microphone and download for free, REW or HolmImpulse (as used by Geddes) then add bass traps and treat first reflection points. Just this will amaze you.

Unless you have your system set up on the long wall where sidewall reflections arrive much later you will need to absorb some of that energy to reduce smearing and congestion. The average room requires about 400ms for the sound to decay evenly across the frequency range by 60dB, known as T60. Tables are available online for different enclosed volumes.

Someone mentioned floor and ceiling reflections which of course is as important as the others. Here though a ceiling 'cloud' works extremely well and a small rug or no rug is fine. The cloud frame needs to be preferably 4" x 6ft x 8ft and hung with a 4" gap below the ceiling. This will act as a broad-band absorber, unlike wall to wall carpet which is narrow-band and harmful to the sound. Consider that your ears are a known, to your brain, fixed distance from the floor so these reflections are not as problematic. We have evolved to allow for this.

Diffusion is good in larger rooms, not so much in small ones. From experience I can confidently state that treating the modal region below the Schroeder frequency is the most effective if you wish to limit the amount of treatment. I'm talking about bass traps, real bass traps and not the silly little scraps of foam that cannot absorb anywhere near bass. They are physically just too small.

GIK do not make 'proper' broad-band absorbers because they will not sell well and would be a nightmare to ship, so they tend to oversell lesser units. I know somebody who returned a few because the room was too dead!

My best advice is to educate yourself as much as possible on this fascinating and immensely rewarding process by reading articles from the right source. Leo Beranek is tough going but the true authority, Foley from acoustic fields not so much.



I like Toole, but let’s be clear that this is his personal opinion about what he likes. For some of us, the acoustics of live spaces can take a toll on our brain power. As others have written, filtering out a room all the time can be exhausting, including academic settings.

I personally want my room a little less present. I like my stereo to be the acoustic equivalent of looking across a mountain range. That feeling of relaxation you get when suddenly you feel like you can see forever, but with my ears.
We ALWAYS listen to our room when we listen music, except that if the controls of the room is right we are not conscious of the room but better aware of the musical flow....

There is no "stereo equivalent of looking across a mointain range", it is not the audio stystem alone that create the sounds impressions, but the room.... It is an unseparable unity, this unity can be horrible or celestial with all the level between the 2....




The subjective impressions caused by the impact of a specific room are subjective and vary for each imdividual, but the recreation of the sound impressions by the brain/ears WITH the recording space cues and the actual cues of the room space are informations absolutely necessary to the experience....This recreation is based on the INFORMATION linked to the recording event and the room event for all of us, even if we are not conscious of the room because we are used to it...To be conscious of the room is simple, go to your basement et compare that sound with your kitchen, and the sound of the next church....

What Toole speak about are not only opinions, but serious trends in acoustical science, and we cannot answer to that:" i prefer the sound of my music coming from my stereo system", forgetting the room....We all want to forget the room... But to do so we MUST control the room....This is precisely the point i made and negating it reveal only that you are not conscious of what is the problem at all... :)

If you have the impression that your room dont exist already without any workings of it it is probably a self ingrained conditionment of your perception.... When the boat takes water anybody can negate reality and say all is well i prefer the infinite view from the soaking boat...

And we must realize that we are not conscious of the impact of our room on the sound except when we experiment with it.... I myself became conscious of the extraordinary contribution of the room by experiments... WITHOUT experiments we cannot be aware of this contributions at all...We can suspect it yes, but being aware of the enormous size of the impact, no, not at all... This is the point of acoustic treatment and controls in audio, where people invest big money in electronics and little or nothing in treatment and controls...This blinders were mine BEFORE my experiments in listenings....

The recording experiment you propose is only to reveal the presence of the room, but will not reveal the constructive/destructive impact of the room... When we lived in a room we became used to it, we are not conscious at all often of his destructive side....And anyway most people dont even believe their own ears.... Suffice to read audio forum to know that....Listening experiments is the ONLY way to create a room... Even computerized solutions has limits....



How much you are taxed by the space, how much you are willing to filter out is very individualized.
I’m sorry @mahgister but I feel that you misread my points in too many ways to count, so I'm going to let that drop there.  It's too hard to answer all that.



Best,

E
i get your point and i apologize if i was insisting...

What you say makes more sense in a vast room, in a small one we are captive of reflections and using it is the best way.... Erasing then partially is not the only and not the better way....Most people listen music in small room like me....And not in a ideal acoustically designed big room...

Anechoic chamber are unbearable by the way....And we cannot have an anechoic chamber impression from a normal room....We can record something in an anechoic chamber, not living in it..... In an anechoic chamber we are missing all information cues that comes from our normal room.... And what Toole or any acoustican know is that the brain NEEDS the recording cues of the lived recording original musical event and the cues from the room where the audio system plays to recreate the music on the best scale possible...The final information comes from the mixing by the brain of the cues coming from the direct waves and the reflected one in a room....There is no normal room who mimic an anechoic one.... It is a delusion or a metaphor to convey a peculiar opinion like: i taste my wine but i prefer that the wine dont come from any glass at all.... And this saying says all.... :)

My best to you....
I was only talking in relative terms, on a scale.

Anechoic room  <================> Drywall and concrete

If tool is in the middle I'm a little to the left of him.  The rest, the importance of reflections is important, too many overuse absorption and don't use enough diffusion.

That is all.

Erik
Ok i get your point.... Sometimes i am too swift to react.... But you dont get mine....About the difference between passive materials treatment and active controls one.... :)

The scale you just draw is about reflections only, not about the recreation of the music from the sound event by the brain  using the cues from the refective room and from the direct waves .... This scale is refering to passive controls methods not active one....There exist always 2 space in one, the recording space, and the actual room space.... The best method to recreate the event is using information not eliminating them only....That was my point.... Ok i will go silent....



My best to you....
The first sidewall reflection point matters in the design of a recording studio control room. Those I have been involved in used angles which direct the reflections away from the normal listening position.

In rooms where that’s not an option, apparently the first sidewall reflections still matter... or at least, what one does at these locations matters. @erik_squires on the subject:

"To my experience, as others here have noted, diffusion at the 1st reflection points are a better idea [than absorption]. They enhance imaging."

One significant difference between diffusion and absorption is, diffusion doesn’t significantly change the spectral balance of the reflected energy, while absorption does. And absorption keeps on having its effect on everything that hits it, not just those first reflections, for better or for worse. Both reduce the amount of early sidewall reflection energy which arrives at the listening location, but diffusion does so more benignly.

Early sidewall reflections have benefits. They DO increase the apparent source width... in other words, they can make the soundstage wider, but some image precision and soundstage depth is lost in the process, along with some clarity. So it’s a tradeoff. If not absorbed, that first sidewall reflection energy lives on to come back as later reflections which convey spaciousness (hall ambience) with no significant downside.

Earl Geddes on the subject of early reflections, which typically include the first sidewall reflections:

"The earlier and the greater in level the first room reflections are, the worse they are. This aspect of sound perception is controversial. Some believe that all reflections are good because they increase the listeners’ feeling of space – they increase the spaciousness of the sound. While it is certainly true that all reflections add to spaciousness, the very early ones (< 10 ms.) do so at the sake of imaging and coloration... the first reflections in small rooms must be thought of as a serious problem that causes coloration and image blurring. These reflections must be considered in the [loudspeaker] design and should be also be considered in the room as well."

Duke
Another confusing controversial thread.  Seems like the only alternative to avoid all this is to buy acoustic measurement software like from Dayton audio and figure out your room. Then treat it accordingly. 
Very good post thanks...

We must NEVER forget that acoustic preparation of a studio recording room has no relation at all with what must be used in a play back audiophile room.... This is not the same thing creating conditions to register something and creating conditions to listen to something.... In the first case the focus in on the instrument that will be recorded, in the second case the focus is about the way the ears/brain recreate the original event....And in these 2 cases the prparation and acoustic organization of the space(room and studio) dont goes under the exact same rules.... Floyd Toole explain that better than i will ever be....

But what is missing in your post is also that there is OTHER options than absorbing, reflecting or diffusing....

These concepts refer to passive treatments perpective...

How about active controls? Using resonance and grid of non electronic but active devices to guide and organize the mixing of direct and reflected waves?
How about putting in place the conditions to made possible "a potential informed wave" for the listening brain...

Most Audio people are slave of their idolized electronic prefered branded components, i am slave now of my room.... :)

Any electronic component ca be easily replaace with an equally good one, the room cannot  and is at the heart of the audiophile experience, not the electronic component.... With dont listen to the electronic components  we listen to the room ...No speakers sound the same in different room....


This is the way i go, with a success so great that there is no more relation between before and after....
Mahgister wrote: " We must NEVER forget that acoustic preparation of a studio recording room has no relation at all with what must be used in a play back audiophile room.... "

Please note that I said "control room", not "live room", the latter being the room where the musicians perform and the actual recording is made.

The goal in the control room are not dissimilar to home audio: To clearly hear what’s on the recording, without any masking or other undesirable signature from the playback room.

Duke
The goal in the control room are not dissimilar to home audio: To clearly hear what’s on the recording, without any masking or other undesirable signature from the playback room.
The room where the recording is made is one room...

The control and mixing room is where the electronic controls of quality are...

But the sound you will listen to is YOUR room, and what you will listen to will never be the ideal standardized generic preparation by mixing and equalization etc of the sound engineer...It will be your specific room...

In a word your brain must learn how to retrieve the cues coming from the recording from the cues coming from your listening room...Your brain dont work like a sound engineer in the mixing room trying to be faithful to the recording only....Your brain need a room....And it will not be the recording room....It will be the room where you live....Your brain will be faithfull to the recording event to the limit of his own actual location: his room experience...

And nobody only listen to what is on the recording hall, or lived event, it is ALWAYS a recreation...

My point is how to make this recreation a stunning experience...

It is ok to have " no masking or any undesirable signature from the play back engineer room" but how will you create ideal listening conditions in your own room?

By using only passive treatment and erasing your room from the sound?

By using active controls and giving to your room an active role?

What is the best?

The best is the cheapest way to create a stunnning audio experience is not upgrading your audio system to a more transparent one at prohibitive cost,but transforming your room in a positive player...The rewarding is astounding and the cost very low....

This is my experiment...This is my point....

Saying that we must listening our stereo system directly to keep the brain calm is saying something that makes no sense at all, except for those who think that electronic engineering is the key audio element ....But is is acoustic the fundamental player...

You can replace any speakers or amplifier or dac, by an equal but different good one, but you cannot replace a room....We live with it and we can transform it tough....

In a word, the role plays by the room treated or not, controlled or not, is absolutely STUNNING, but unbeknownst to most audiophile focus centrered on their favorite electronic component they sometimes taste, it  seems like branded cheese, keeping their brain " calm "outside the " tumult" of their room it seems, directing their attention to the recording.......  :)

This is  my point....
Mahgister wrote: "how will you create ideal listening conditions in your own room?"

That would take a while for me to answer and would de-rail or hijack the thread.

I get the impression that you have something you’d like to share:

"The best is the cheapest way to create a stunning audio experience is not upgrading your audio system to a more transparent one at prohibitive cost, but transforming your room in a positive player...The rewarding is astounding and the cost very low....

"This is my experiment...This is my point.... "

It sound like you are very excited about something you have done in your room. Maybe you could start a thread about it?

Duke
we speak about first reflections point and their obstructiveness or usefulness...

It seems to me that i was speaking about that...

It seems to you otherwise...

You do not enjoy a change of perspective it seems?

Perhaps it will be a good idea to read Floyd Toole article...You will have a cue of what i speak about ...

My best to you... I will go....

Mahgister, it sounded to me like you have created a "stunning audio experience" by doing something to you room, but I have absolutely no idea what you have done. I have no idea what your "change of perspective" is, but would like to. You seem to be very excited about it.  Have you discovered something new?

It also sounds like you may feel offended by something I said, which was not my intent. If you want to talk about that too, feel free.

Which Floyd Toole article are you referring to? I’m somewhat familiar with his work on sound reproduction, and on the acoustics and psychoacoustics of loudspeakers and rooms.

Duke
Like usual i react too swiftly to your post...

I apologize to you...

You are a good faith person and i am too passionnate...

I apologize in double...

https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation

This article is only few months ago...very interesting to say the least...

I had not speak about my own way and experiments with my room here my goal was not to derail the thread...

I only refer to them by the concept of active controls of room by relation to passive treatment of room...

I related my 2 years journey in my thread...

"Miracles in audio....."

My goal was with only homemade device and very low cost materials transform an audio system to a totally new level...

I expose how with the concepts of the 3 embeddings of an audio system, the most powerful being acoustic, but the electrical embeddings being also very powerful.... The mechanical embedding being important but less powerful...The acoustic methods has 2 way: active and passive.... The active way is almost unheard of in any audio thread... The "superstition" that we must eliminate reflection points instead of working with them comes from that ignorance about active controls and the way the brain work to recreate a lived sound event from a recording in an actual room....

Ok i dont wanted to derail the thread ....

My deepest regards to you....
Seems like the only alternative to avoid all this is to buy acoustic measurement software like from Dayton audio and figure out your room. Then treat it accordingly.

Sigh, I don't know.  I mean, honestly, I know speakers more than acoustics, and I think that for the average audiophile, this is a steep learning curve.  I mean, if you want to learn about acoustics, then YES, get yourself a mic and some software young lady/young man and go west with the wagon train...

Fun stuff.

But when I think of how to be helpful, what can I say which helps audiophiles enjoy their systems longer, better, asking the pros for help is a better way to go, along with some experimentation here and there.
Mahgister wrote:  " I related my 2 years journey in my thread... 

"Miracles in audio....." 

Thank you very much.  And thank you for the link to the Audioholics article,    I'll look at both. 

Duke
As a fanboy of active room eq and the means to accomplish such...

A pair of ears, however compromised and even biased, can hear and discern 'details' that a calibrated mic with it's software may only hint at, or 'gloss over'.

Mho, one would need to be running some rather sophisticated wares, running in r/t into a 3D waveform to catch 'reflections'...and, even then. they'd likely be effected by frequency, harmonics...and even ones' presence in the space....

...and be very persistent and equally patient in the measurement routine.

I am an imperfect being in an imperfect world, surrounded by imperfect 'things' playing imperfect sounds.

Eventually.....one has to accept ones' limitations...

(Thanks a whole bunch, Harry....*smirk*)
(....now, if we could only get kenjit to accept that....the world would be slightly brighter and shiny once again....)
*tongue Very Deep in cheek*
The closer the reflection point is to the speaker the more it will matter. Likely more evident in smaller rooms.

 In my case, side walls are about 2feet away from the speakers. I treated them with a diffuser/absorber combo panels (soundplanks from ASC) and it  tamed down the brightness a bit as per my goal. But It also reduced soundstage width a little.