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Synthpark 15th August 2019 05:50 AM

Quote:

Originally Posted by Soundman2020 (Post 14149882)
Below are some graphs that show how the actual HRTF function works, and the frequencies that are used to provide that sense of direction.

As you can see, there just isn't much precision at all in the low end. Stereo imaging happens in the high mids and highs, not the lows. Yes, a female singer might be able to get down to 200 Hz, but that's not where most of the energy in her voice is: it's much higher up the spectrum.

So, once again, we get back to the issue: if you move your speakers close to the front wall in your room, and you get degraded stereo imaging, then there's something wrong with the way the room is treated, because the front wall does not affect stereo imaging in a normal room, properly treated, as NSM and others have pointed out.

- Stuart -

Wow you must be really obsessed with this subject, obsessed to the point of madness. You are like a user called Swardle in the electronic music forum. I have 10 minutes before going to my job interview.

I showed you a graph of which frequencies are transmitted with what attentuation at what angle. For every speaker you can measure such a graph. If you are unaware of such a graph, then game over. This has nothing to do with what you posted here.

And as a best acoustician in the world, you should know that SPEAKER SIZE matters in that respect, but no hint from your side. The bigger ther speaker front, the less sound will bend over (ther lower the cutoff frequency). No hint from your side. Because there are serious gaps in your knowledge to be the best acoustian ever.

Quote:

Originally Posted by Soundman2020 (Post 14149870)
So you have an LCR console and three speakers in your room, and you do stereo mixes on that? Unusual.... I normally only use LCR consoles in live events and for fixed installations, such as some churches and theaters, where ordinary mono or two channel doesn't do the job well. I'm not aware of too many pro mixing rooms that mix stereo in LCR! I know of quite a few that mix stereo on 5.1 and 7.1 systems, but none that mix in 3.0. Why did you set up your place like that? There can't be much of market for the mixes, I would think...

- Stuart -

This slowly gets on my nerves :lol::facepalm:
Before typing, use google first.

https://producelikeapro.com/blog/l-c...ixing-in-mono/

"LCR mix" is an old way of mixing, panning either left, center, or right. Some engineers still use it (with some exceptions applied here and there).

Famous LCR mixes

For the interest of this subforum it is better to stop this conversation. You post your mdat which I requested I think 2 weeks ago and I post mine, although my room is currently neither acoustically nor cosmetically finished (some tuned absorbers are to be designed and placed) and some trolls will see their chance to make fun of this and that.

So you are talking about mixes exceeding the width of the speakers (Alice in Wonderland), but haven't even heard of LCR mixing technique, so yeah: game over (Super Mario hits a barrel).

Quote:

Originally Posted by Soundman2020 (Post 14149870)
And no, that's not the data from my best studio. Just one of many.

Ok, you are the best acoustician in the world. But wait: there isn't any evidence for that, no photos, no references.

I am not nearly a fan of this guy below, but look what he writes:

http://www.acousticsinsider.com/flat...ency-response/

Soundman2020 15th August 2019 07:47 AM

Quote:

I showed you a graph of which frequencies are transmitted with what attentuation at what angle. For every speaker you can measure such a graph. If you are unaware of such a graph, then game over. This has nothing to do with what you posted here.
Your graphs are absolutely irrelevant to the way humans perceive the stereo image, which depends on our ability to determine angles, which in turn depends on the HRTF. The speaker directivity has no bearing on the way your ears and brain work to determine where sound is coming from. That's what we were talking about. You claimed that we have the ability to accurately determine directionality and stereo imaging for frequencies below 500 Hz. I was merely showing that your claim is false: humans do not possess that ability. The formation of the stereo image inside your head is due mostly to higher frequencies, where we do have the ability to accurately determine directions. For lower frequencies, we just aren't very good at discerning direction. Hence the common statement that bass is not directional. For mids and highs, our brains are really good at this, but the lower down in frequency you go, the poorer our ability gets, until in the low bass range, there's no ability at all.

That's the point.

Which gets us back to the original point: putting speakers against the front wall does not damage the stereo image, because the frequencies that determine stereo imaging are not affected by placing speakers against the front wall! It's that simple.

At best, if you had a very small speaker, tight up against the front wall, you MIGHT get an effect at maybe 350 Hz, perhpas even 400 for a tiny speaker... but it would have to be VERY small speaker, to be able to get it close enough to the wall. For any realistic studio monitor, the highest possible frequency that cold be affected is going to be rather lower.

So, please do pay attention here, and try to follow the logic, since you seem to get lost in logical reasoning rather easily.

The highest frequency that can realistically be affected by SBIR, is around 300 Hz. At 300 Hz our ears and brains are not very accurate at determining directionality and therefore stereo image, due to the reasons you can clearly see on the graphs I posted. Thus, the frequencies that give us the ability to accurately determine direction and stereo imaging, are higher than the frequencies that can be affected by placing your speakers against the front wall. Thus, what everyone here has been trying to tell you is true: placing speakers against the front wall does not damage the stereo image.

Now, since in your room, you DO experience such a problem, clearly it is not due to the proximity of the speakers to the wall: logically, it must be due to some other reason, and NMS gave you that reason: your room has an issue with treatment on the rear wall, which produces an overwhelming acoustic response when you put your speakers against the front wall that somehow messes with your ability to determine directionality.

That's the issue here: the polar plot for the speakers is irrelevant. What matters is how your ears and brain determine the stereo image, and they do so by using only frequencies that are very much higher than those which can be affected by having the speakers against the front wall.

If you didn't understand that explanation, then try reading it over again slowly, and think it through. It's not hard to understand.

Quote:

Wow you must be really obsessed with this subject,
Thanks for the compliment! That's very kind of you. Yes, I am obsessed with acoustics. It's my passion. I love to study it in as much depth as I can, to understand it as well as I can, both in theory and in practice, so I can design better rooms. It certainly is my obsession! I do appreciate it that you recognized this.

Quote:

And as a best acoustician in the world, you should know that SPEAKER SIZE matters in that respect, but no hint from your side.
Speaker size has no effect on how your ears and brain build the stereo image. That is determined mostly by the HRTF, which is not related to the size of the speakers in any way, nor to the directivity plot of the speakers. It's a psycho-acoustic issue. It is even possible (and simple) to fool your ears into thinking that the stereo image has been shifted left or right when in fact it has not moved at all, just by modifying the signal in one speaker very slightly, in one of several possible ways. It's an eyeopener when you actually do that in practice, and hear the image shift around when you fiddle with things like timing and phase.

So, just to clarify: you are looking in the wrong place for the reason why you have a stereo image problem in your room, when you put the speakers against the front wall. The problem is due to room treatment, not to proximity to the walls. What is probably happening is that you are moving your speakers to a different location, where the cause a different response in the room, and since the room is not treated correctly, the new response is overwhelming in some sense, that messes with your ability to determine the directionality, and stereo image.

Which brings us full circle: you have a room treatment problem, because placing speakers against the wall does not have the ability to damage the stereo image, as is demonstrated by the HRTF graphs, and common acoustic knowledge.

Quote:

The bigger ther speaker front, the less sound will bend over (ther lower the cutoff frequency).
Once again, that's irrelevant to what we are talking about here. The baffle step response issue has no effect on your ability to determine the stereo image.

Quote:

"LCR mix" is an old way of mixing, panning either left, center, or right. Some engineers still use it (with some exceptions applied here and there).
You mean hard panning? You really should write more clearly then! When you talk about "LCR mixing" to a live sound engineer, what comes to mind is LCR consoles, central clusters, and suchlike. If you were to write more clearly, you would be able to get your point across better.

Quote:

You post your mdat which I requested I think 2 weeks ago and I post mine
You seem to have a very short memory, or maybe you just aren't paying attention (or both). I already explained, clearly and concisely, just a short while ago, that the MDAT you are referring to is not mine to post: it belongs to one of my clients. He paid for the studio design, and the tuning process, so the data is is his. It's not from my own personal studio, so I have no control over what can and cannot be done with it: I can only do what the client allows me to do.

Your MDAT, on the other hand, is yours. The only restrictions on posting it in public are the ones you place on it yourself. You are free to publish it any time you want.

Quote:

although my room is currently neither acoustically nor cosmetically finished
And that's fine too! If you check back, you'll notice that I did post graphs from several stages of the construction and treatment of that room, with all the ugly stuff still visible in some of them. It doesn't matter if the REW data fro a parly treated room looks ugly: that's what the treatment process is all about! Identifying the problems visible in the REW data, so suitable treatment can be designed and installed to deal with those problems. It's no shame to post data for a room that isn't finished yet.

Quote:

So you are talking about mixes exceeding the width of the speakers (Alice in Wonderland),
It's not hard to achieve. You even said yourself that you once worked in a temporary room that had such a response, so I'm not quite sure what your "Alice in Wonderland" comment is about... maybe you just fantasized about working in such a room? Is that it?

Quote:

But wait: there isn't any evidence for that, no photos, no references.
Oh, but there's plenty, if you just go looking for it. :)

Quote:

I am not nearly a fan of this guy below, but look what he writes:
I can see why you are not a fan! Half of what he says simply isn't true. It seems to me that he was unable to get flat response in his room, so he wrote an article to justify why he cannot get flat response! :) It's strange he would claim that it isn't possible to do that, when there's many examples of flat response right here on GS, as well as on other forums, and even on some studio websites. Just because he's never figured out how to achieve it doesn't mean that others can't do it...

In any case, "flat frequency response" isn't the end goal for a fully tuned room. It's better to apply a slight "tilt" to that, such that there's a very small boost at around 80 Hz, then a very slight falling off across the rest of the spectrum, to be a couple of dB down at 20 kHz. There's several such house curves: probably the most often mentioned is the B&K curve, from about 40 years ago. It ha stood the test of time, and has proven to be pretty good. I use a slight variation in my rooms, but I won't be revealing what that is... :)

- Stuart -

nms 15th August 2019 09:42 AM

Haha.. alright, most probably this is a good time to just let this thread die. Save yourselves from wasting anymore time or aggravation on it!

Brian M. Boykin 15th August 2019 12:31 PM

Quote:

Originally Posted by nms (Post 14150180)
Haha.. alright, most probably this is a good time to just let this thread die. Save yourselves from wasting anymore time or aggravation on it!

I knew I was going to move into my current room 6 months ago. I’ve been reading up and refreshing my memory since the beginning of the year. I’m currently treating first reflections and hope to have them covered by the end of the year and I’m doing preliminary measurements now. This thread has expanded my understanding of acoustics and connected numerous dots. Soundman2020 has dropped so much knowledge and reinforced all that I’ve read across several books and several websites of manufacturers. This is common, agreed upon knowledge industry wide and Soudman2020 deserves a medal. I’ve applied small room techniques for the last 2 months and heard a drastic improvement. It’s mind boggling how anyone can study the science of acoustics and can not grasp the front wall concepts Soundman2020 is explaining.

Synthpark 15th August 2019 01:03 PM

Quote:

Originally Posted by Soundman2020 (Post 14150088)
It's not hard to achieve. You even said yourself that you once worked in a temporary room that had such a response, so I'm not quite sure what your "Alice in Wonderland" comment is about... maybe you just fantasized about working in such a room? Is that it?

Oh, but there's plenty, if you just go looking for it. :)

I can see why you are not a fan! Half of what he says simply isn't true. It seems to me that he was unable to get flat response in his room, so he wrote an article to justify why he cannot get flat response! :) It's strange he would claim that it isn't possible to do that, when there's many examples of flat response right here on GS, as well as on other forums, and even on some studio websites. Just because he's never figured out how to achieve it doesn't mean that others can't do it...

In any case, "flat frequency response" isn't the end goal for a fully tuned room. It's better to apply a slight "tilt" to that, such that there's a very small boost at around 80 Hz, then a very slight falling off across the rest of the spectrum, to be a couple of dB down at 20 kHz. There's several such house curves: probably the most often mentioned is the B&K curve, from about 40 years ago. It ha stood the test of time, and has proven to be pretty good. I use a slight variation in my rooms, but I won't be revealing what that is... :)

- Stuart -

In any case, Stuart, it is your "home game", like when a football team visits another and gets a constant "boooohhh", you know what I mean?!

So first of all, the guy referred to other measurements of the very best acoustical designers around, his own ones appeared later. Have you actually looked at the side? I don't think so.

Once again, if the stereo width is wider than your speaker tweeters, there is likely to be an anomaly in the room, caused by side wall reflections mixing with your direct signal and dragging it further outside.

Was that clearly explained? I hope so. Sometimes good to repeat things two times, three times, until the other person finally cannot ignore the argument anymore.

Synthpark 15th August 2019 01:10 PM

Quote:

Originally Posted by Soundman2020 (Post 14149882)
Sorry, but that's wrong again. Your hearing apparatus does not have much ability to accurately determine direction below 500 Hz. All that you showed was the directivity plot of a speaker, which isn't even a polar plot, and bears no relationship at all to the way we hear and determine the direction that sound came from.

Below are some graphs that show how the actual HRTF function works, and the frequencies that are used to provide that sense of direction.

As you can see, there just isn't much precision at all in the low end. Stereo imaging happens in the high mids and highs, not the lows. Yes, a female singer might be able to get down to 200 Hz, but that's not where most of the energy in her voice is: it's much higher up the spectrum.

So, once again, we get back to the issue: if you move your speakers close to the front wall in your room, and you get degraded stereo imaging, then there's something wrong with the way the room is treated, because the front wall does not affect stereo imaging in a normal room, properly treated, as NSM and others have pointed out.

- Stuart -

Wow thats such a wrong interpretation of the subject.

https://de.wikipedia.org/wiki/Head-R...nsfer_Function

Its German

Quote:

Die Head-Related Transfer Function (meist nur HRTF, seltener kopfbezogene oder Außenohr-Übertragungsfunktion) beschreibt die komplexe Filterwirkung von Kopf, Außenohr (Pinna) und Rumpf. Diese Amplituden-Auswertung ist neben den Laufzeitdifferenzen zwischen den Ohren wesentliche Grundlage unseres akustischen Lokalisationssystems.
HRTF-Filterwirkung

Die Elevation der Schallquelle verursacht keine Laufzeitunterschiede, ebenso wenig wie eine Unterscheidung zwischen frontaler und rückseitiger Schallquelle über die sonst für unsere Lokalisation so fundamentale Laufzeitdifferenz möglich wäre. Im Obertonbereich versagt die Laufzeitlokalisation völlig, weil mehrere Wellenlängen des Schalls in den Ohrabstand passen und die Auswertung dadurch ambivalent wird.

Deshalb sind wir zusätzlich auf die Auswertung von Amplitudenunterschieden angewiesen. Diese nehmen mit der Frequenz zu, weil Beugungseffekte an Kopf und Rumpf mit steigenden Frequenzen bzw. kürzeren Wellenlängen schwächer werden und somit der Schallschatten ausgeprägter wird. Bei weiter steigenden Frequenzen ermöglichen winkelabhängige Resonanzerscheinungen am Außenohr die Lokalisation in der Elevationsebene.

Prinzipiell sind diese Anhebungen und Absenkungen in den Blauertschen Bändern beschrieben, doch ist vor allem die Lage der Nullstellen in den Resonanzerscheinungen individuell sehr verschieden. Weil die HRTF-Lokalisation hauptsächlich auf erlernten Reizmustern beruht, kann aufgrund der anatomischen Unterschiede keine verallgemeinerte Funktion angegeben werden. Auch die Kunstkopf-Stereofonie, die auf dieser Filterwirkung beruht, arbeitet nur zufriedenstellend, wenn die Unterschiede zur hörenden Person nicht zu groß sind.

Bei der auf Phantomschallquellen basierenden Lautsprecherwiedergabe führt die komplexe Filterwirkung des Außenohrs zu deutlichen Fehlern, weil der Einfallswinkel der Wellenfronten meistens nicht mit dem Originalschallfeld übereinstimmt. Dadurch werden starke Amplitudenfehler verursacht, die u. a. zur Elevation der Phantommitte (Center) führen. Abhilfe könnte nur eine physikalische Rekonstruktion des Originalschallfelds bringen, wie sie im Holophonie-Ansatz angestrebt wird.
It basically says that amplitude differences are needed for higher frequencies because time-of-arrival stereophony FAILS for higher frequencies. But that means that time-of-arrival stereophony DOES NOT FAIL FOR LOWER FREQUENCIES.

You completely abused the subject. :)
Play 300 Hz over your loudspeakers, left, middle, right. You cannot localize the source? Something wrong with your ears?
I hope not :)

Another source:

https://de.wikipedia.org/wiki/Lokalisation_(Akustik)

So sorry that its in German (use google translator?)

Quote:

Bei tiefen Frequenzen unterhalb von ca. 800 Hz werden vor allem Laufzeitunterschiede ausgewertet (Phasenlaufzeiten), bei hohen Frequenzen oberhalb von ca. 1600 Hz vor allem Pegelunterschiede. Dazwischen liegt ein Überlappungsbereich, in dem beide Mechanismen eine Rolle spielen. Die Qualität der Richtungsbestimmung wird hiervon aber nicht beeinträchtigt.
It tells one that below 800 Hz, time-of-arrival is exploited (for frequencies well above 80 Hz). Q.E.D.

So lets sort out things:

a) Frequencies from roughly 200-600 Hz are somewhat affected by front wall when placing speaker near the wall (depending on speaker size)
b) Frequencies from roughly 200-800 Hz are also responsible for localization.

now add (a) plus (b) = (c):

(c) Locating the speaker near the wall may impact the stereo image.

You helped, Stuart, to find these things. Thank you so much.

best regards
Synthpark

dinococcus 15th August 2019 01:55 PM

Quote:

Originally Posted by nms (Post 14149879)
Distance from the wall with rear ported speakers comes up now and then, but in reality I think the speaker angle is sufficient enough to allow the port to function well enough. What's your take on that Stuart?

it existes speakers and sub with the port under the bottom

the adam sub 15

https://www.thomann.de/fr/adam_sub_15.htm


proac d28

https://www.google.fr/search?tbm=isc...h=578&dpr=1.25

Soundman2020 16th August 2019 07:21 AM

Quote:

Wow thats such a wrong interpretation of the subject.
Ummmm.... you should probably tell that to Kleiner and Tichy, then see if you can convince them to explain it to Floyd Toole as well... Good luck with that! :)

Summary: as with pretty much everything else in acoustics, your interpretation here is way out there, past the edge of sanity... I'm getting just a little tired of trying to explain things to you in simple terms, then you go shooting off on an irrelevant tangent, and think you managed to prove.... well I'm not even sure what you imagine did prove! There really isn't much point in trying to help you any more, since it's pretty clear you don't want help: you only want to rant about silliness, as audiophiles often do.

One more time: placing speakers against the front wall does not destroy the stereo image in a properly treated room. Only in your room. End of story.

- Stuart -

Synthpark 16th August 2019 07:40 AM

2 Attachment(s)
Quote:

Originally Posted by Soundman2020 (Post 14152012)
Ummmm.... you should probably tell that to Kleiner and Tichy, then see if you can convince them to explain it to Floyd Toole as well... Good luck with that! :)

Summary: as with pretty much everything else in acoustics, your interpretation here is way out there, past the edge of sanity... I'm getting just a little tired of trying to explain things to you in simple terms, then you go shooting off on an irrelevant tangent, and think you managed to prove.... well I'm not even sure what you imagine did prove! There really isn't much point in trying to help you any more, since it's pretty clear you don't want help: you only want to rant about silliness, as audiophiles often do.

One more time: placing speakers against the front wall does not destroy the stereo image in a properly treated room. Only in your room. End of story.

- Stuart -

Is it not embarrassing claiming that 300 Hz cannot be tracked by the ears in the pan position? It shows very little understanding of the whole material. Your ignorance is to the point of the "elephant in the room problem". Maybe you should rewrite Wiki and other sources which prove you wrong.

I thought you wanna help people, but help requires giving GOOD advices, not to put every sort of speakers against the front wall claiming it will have no detrimental effect at all, and **** up the mids. Helping means responsibility. It seems that your ego is the only important factor here and you are not interested in finding any realistic answer.

There you see it: back reflection in the mid range for a mass product like Yamaha HS7 (size matters here most) is very high, well above -10 dB, and not -20 dB. It can be as high as -6 dB. Stereo image ****ed up. Real-world measurements versus your odd argumentation. ;)

Quote:

Originally Posted by Soundman2020 (Post 14152012)
as audiophiles often do.

No audiophilism means no room treatment required.

Quote:

Originally Posted by Soundman2020 (Post 14152012)
Ummmm.... End of story.

- Stuart -

signed

Soundman2020 16th August 2019 03:35 PM

Repeating an ignorant and incorrect statement over and over won't make it true. But nice try anyway. :)

For the record, as intelligent people can easily see: our brains and ears use higher frequencies to create the stereo image, not lows. And placing a pair of speakers against the front wall does not destroy the production of the stereo image.

Quote:

not to put every sort of speakers against the front wall claiming it will have no detrimental effect at all, and **** up the mids.
So now your argument degenerates into vulgarity, strawmen and personal attacks? A sure sign that you realize just how wrong you are! :) That's what people do when they don't have a valid argument based on facts and logic: instead of attempting to present their position, they devolve into insults, and then erecting strawmen, like you are doing here. Now you are trying to claim that I said: "Is it not embarrassing claiming that 300 Hz cannot be tracked by the ears in the pan position?". Strawman. And that I said: "placing speakers against the front wall has no determinant effect", which I never said. Nor even implied. Strawman.

In fact, I said the exact opposite: placing speakers against the front wall moves the SBIR dip upwards, to a frequency that is less noticeable and that can be treated. It's still there, and still "detrimental", until you treat it: it's just less detrimental. Placing speakers anywhere in a small room is detrimental, in one way or another. Placing them against the front wall is the least detrimental, since it does not damage the stereo imaging and the SBIR dip is less objectionable (among other advantages). It's still not a great position, but it's better than any other, precisely for these reasons (among others). The stereo image stays in tact, the SBIR dip is higher up at a frequency where it isn't so terrible, it is usually lower in amplitude, and it can be treated.

Quote:

There you see it: back reflection in the mid range for a mass product like Yamaha HS7 (size matters here most) is very high, well above -10 dB, and not -20 dB. It can be as high as -6 dB
You are still looking in the wrong place. The directivity of the speaker does not have much effect on the way the human brain determines the stereo image (assuming your ears are roughly on-axis to the speakers). The size of the speaker does not have much effect on the way the human brain determines the stereo image. The stereo image is a psycho-acoustic effect, not a speaker effect, and is created in your head by your ears and brain: it is determined mostly by mid and high frequencies, as shown very clearly in the graphs I posted from Kleiner and Tichy.

Now, before you start building more strawen, let's clarify that the speakers are involved, and so is the room. If the speakers are not set up properly, or if the room is treated poorly, such that the psycho-acoustic clues are masked (which is what is happening in your room), then the information that your ears and brain need in order to form the stereo image are not there any more, and the stereo image disappears, or becomes skewed, or is exaggerated. Put two speakers at one end of a large concrete pipe, and there will be zero possibility of your ears forming a stereo image, EVEN THOUGH THE SPEAKERS ARE PRODUCING ONE! Let that sink in for a second. It is quite possible to have a pair of speakers that are perfectly balanced, playing music with a nice broad stereo arrangement, but the room totally destroys any possibility of actually hearing that as a stereo image. The clues as to the stereo image are small, and even though our ears are sensitive to them, it's easy to overwhelm them completely, as NSM pointed out a while back, such that your brains can't make any sense of them, and there is no stereo perception. This is NOT (as you imagine) because the speakers are not producing stereo any more! They are still producing a good stereo image just fine, even if they are against the front wall: the stereo image is not damaged. The problem is that the room response is so overwhelming that your ears and brain cannot make sense of it as stereo any more, so you cannot hear the stereo, even though it is there.

That's the issue that you don't want to see: In your room, there is something wrong with the treatment that prevents you hearing the stereo image properly. It's not because there is no stereo image, as you state, but rather because your room treatment prevents you from hearing it. The stereo is still there, just overpowered by the room response. The subtle clues that your brain needs to correctly form the stereo image again in your head are drowned out by the room response.

If what you claim actually were true, and placing speakers against the wall actually did destroy the stereo image, nobody would have ever bought "hi-fi" and "home stereo" systems for their living rooms, because that's the way they are pretty much always set up! Speakers tight up against one wall. But those systems can be heard in stereo (lousy stereo, but still stereo). Because placing the speakers against the wall does not destroy stereo.

Ditto for contemporary flat-panel TVs. In most living rooms, they are hung on the wall, or on stands very close to the wall... and yet they still produce stereo images, which can be heard quite well. If what you claim were true, there would be no such thing as stereo listening for flat panel TVs and home stereo systems... Yet there is. Stereo works just fine for those.

So your claim is shown to be false, and the reason why YOUR room doesn't give you a good stereo image is not due to the speakers being against the wall, but rather due to the incorrect/incomplete treatment in the room, and especially the lack of treatment on the rear wall. If you do not have comprehensive, suitable, complete treatment on the rear wall, then the room response WILL manage to overwhelm the stereo clues when you place your speakers against the front wall. And once again, it's not because placing the speakers against the front wall somehow destroys the stereo image: it doesn't. It's because in that location they trigger a room response that hides the clues your ears and brain need to form the stereo image again, in your head. The stereo is still there: the speakers are still producing it. But AT THE MIX POSITION, the room response is too powerful for your brain to be able to pick out the clues.

That's the issue.

Because in a properly treated room, placing speakers against the front wall does not destroy the stereo image.

It really is that simple. Once you complete the treatment of your room (assuming you do it correctly), you will no longer experience this effect, and you will be able to place your speakers in the best location, which is against the front wall.


- Stuart -

Synthpark 16th August 2019 11:23 PM

Yeah, amazing.

Quote:

Originally Posted by Soundman2020 (Post 14152433)
Repeating an ignorant and incorrect statement over and over won't make it true. But nice try anyway. :)

Indeed. You like to change the focus. Remember: with rising number of words each word and sentence is decreased in importance and gets less attention. :)

Quote:

For the record, as intelligent people can easily see: our brains and ears use higher frequencies to create the stereo image, not lows. And placing a pair of speakers against the front wall does not destroy the production of the stereo image.
Nobody was speaking of lows but the mid-range starting at 200 Hz and ending around 1 khz, which relies on time-of-arrival between left and right ear to determine directivity. Directivity is part of the story. So distorting the midrange by near-by reflections means to deteriorate the stereo image.

Quote:

In fact, I said the exact opposite: placing speakers against the front wall moves the SBIR dip upwards, to a frequency that is less noticeable and that can be treated. It's still there, and still "detrimental", until you treat it: it's just less detrimental. Placing speakers anywhere in a small room is detrimental, in one way or another. Placing them against the front wall is the least detrimental, since it does not damage the stereo imaging and the SBIR dip is less objectionable (among other advantages). It's still not a great position, but it's better than any other, precisely for these reasons (among others). The stereo image stays in tact, the SBIR dip is higher up at a frequency where it isn't so terrible, it is usually lower in amplitude, and it can be treated.
That seems to be a poor mans solution. I understand your strategy relies on it and you don't want that your strategy breaks down like a house of cards, but that is what happens. You want every argument from my side to ignore with a "strawman?". You think its so easy to get away? How do you want to treat a notch frequency which goes up differently than to place an absorber at the front wall?

And what also the point is: it is not ONE dip frequency only, can be two or three, a comb filter.

I understand that when assumptions are not as bullet-proof as assumed the comfort zone is lost. :)

Quote:

You are still looking in the wrong place. The directivity of the speaker does not have much effect on the way the human brain determines the stereo image (assuming your ears are roughly on-axis to the speakers).
I don't know how I can make this even more clear to you what every intelligent and average intelligent person would understand anyway: the directivity determines how much sound is bend over and reflected by the front wall, disturbing frequency response and potentially the stereo image.

Quote:

The size of the speaker does not have much effect on the way the human brain determines the stereo image.
Patiently to the point of complete absurdity I answer to all your comments: Yes it does. Smaller speakers will have more sound bending over (due to the wave nature of sound causing diffraction) and therefore more SBIR.

Quote:

The stereo image is a psycho-acoustic effect, not a speaker effect, and is created in your head by your ears and brain: it is determined mostly by mid and high frequencies, as shown very clearly in the graphs I posted from Kleiner and Tichy.
You posted only half of the story: in the same book there are enough remarks about time-of-arrival, just look a bit deeper.

Quote:

The problem is that the room response is so overwhelming that your ears and brain cannot make sense of it as stereo any more, so you cannot hear the stereo, even though it is there.
Exactly: its the room! More precisely, it is the disturbing front wall.

Quote:

That's the issue that you don't want to see: In your room, there is something wrong with the treatment that prevents you hearing the stereo image properly.
In my room, the stereo image is amazing, did I say something else? And the reason for that is my front wall absorber, my side wall absorbers and the diffusors behind me, as well as the big ceiling absorber, all reflection points treated.

Quote:

If what you claim actually were true, and placing speakers against the wall actually did destroy the stereo image, nobody would have ever bought "hi-fi" and "home stereo" systems for their living rooms, because that's the way they are pretty much always set up!
Saying that means you have never visited any hifi forum where people treat their rooms to get the best out of their hifi speakers. I even posted a link. Go back and read that thread. Never heard of people being quite disappointed with their new hifi equipment, which "sounded much better in the shop"? Welcome back to reality.

Saying that my CANTON hifi equipment in my living room sounds pretty nice and beats 90% of all cost-aware pseudo studio monitors. These are towers. They have the big advantage that ground reflection is not a concern compared to two-way speakers on stands.

On the other hand, the stereo image is hardly there. Because you are so completely unaware of all this I am very pleased to inform you that the reason for all the two-way systems in the studio market is that stereo image is superior, because these speakers are better approximations of a point source.

Quote:

Ditto for contemporary flat-panel TVs. In most living rooms, they are hung on the wall, or on stands very close to the wall... and yet they still produce stereo images, which can be heard quite well. If what you claim were true, there would be no such thing as stereo listening for flat panel TVs and home stereo systems... Yet there is. Stereo works just fine for those.
If you never heard real stereo in your life it will be difficult for you to judge it. :)

Quote:

So your claim is shown to be false, and the reason why YOUR room doesn't give you a good stereo image is not due to the speakers being against the wall, but rather due to the incorrect/incomplete treatment in the room, and especially the lack of treatment on the rear wall.
Yeah here we go again: where did I say, my stereo imaging is bad? :)

Quote:

Because in a properly treated room, placing speakers against the front wall does not destroy the stereo image.
Yeah keep on repeating it over and over again. Weekend is coming ...

sage691 17th August 2019 02:42 AM

Quote:

Originally Posted by Synthpark (Post 14153192)

In my room, the stereo image is amazing, did I say something else? And the reason for that is my front wall absorber, my side wall absorbers and the diffusors behind me, as well as the big ceiling absorber, all reflection points treated.

You were asked before to post 3 REW Mdats of your mix position -- L & R (Stereo), L and R single speaker.

You say your room is "amazing". Well, you could easily prove that by posting the requested Mdats.

Me and others here are waiting. Until then you just seem ridiculous.

Getting "amazing" results in any critical listening room is a Herculean task that is 100X more difficult than what 99.9% of people would be willing to endure.

The proof is in the pudding.

Soundman2020 17th August 2019 03:03 AM

Quote:

Originally Posted by Brian M. Boykin (Post 14150304)
I knew I was going to move into my current room 6 months ago. I’ve been reading up and refreshing my memory since the beginning of the year. I’m currently treating first reflections and hope to have them covered by the end of the year and I’m doing preliminary measurements now. This thread has expanded my understanding of acoustics and connected numerous dots. Soundman2020 has dropped so much knowledge and reinforced all that I’ve read across several books and several websites of manufacturers. This is common, agreed upon knowledge industry wide and Soudman2020 deserves a medal. I’ve applied small room techniques for the last 2 months and heard a drastic improvement. It’s mind boggling how anyone can study the science of acoustics and can not grasp the front wall concepts Soundman2020 is explaining.

Thank you for the comment! I'm glad to have been of some help with your room, even if indirectly. I do hope your room works out well! From what you say, I don't doubt that it will be great. kfhkh

- Stuart -

Soundman2020 17th August 2019 03:09 AM

Quote:

Originally Posted by nms (Post 14150180)
Haha.. alright, most probably this is a good time to just let this thread die. Save yourselves from wasting anymore time or aggravation on it!

Good advice! I think you are right. There's no point in me continuing to try to educate and explain, when the conversation from the other side degenerates into insults, vulgarity, and strawman arguments. The truth is out there: almost everyone here sees it. There's a saying in Spanish (and probably an equivalent in English too, but it escapes me right now), that roughly translated goes something like this: No one is so blind as the person who refuses to see. :)

- Stuart -

Northward 17th August 2019 11:35 AM

1 Attachment(s)
Considering that the acoustic treatment in the room is well planned and equal in both scenario:

- if your studio has a properly shaped shell front wall 30°-0°-30° such that at sweet spot with speakers against the wall (and perpendicular to the wall) your are effectively in a quasi minimum phase SBIR scenario, the effect of speakers against front wall cannot have a negative effect on stereo and depth perception, and should in fact greatly enhance it. If the speakers are quite small, their Omni response / edge diffraction may be pushed higher in frequency and affect depth perception negatively. Not stereo. So beware of speaker choice.

- if your are dealing with a flat front wall (not shaped): depending on speaker size, while in general it should still be beneficial to stereo image it can in certain scenarii create negative first (and second) order reflections that have a negative influence. While possible, it is unlikely. Again, speaker size / edge diffraction /polar pattern plays a big role in that.

The secret is shell shaping to optimise quasi minimum phase response.

The last studio we did that way is this one:

nms 17th August 2019 11:41 AM

Quote:

Originally Posted by Synthpark (Post 14153192)
That seems to be a poor mans solution. I understand your strategy relies on it and you don't want that your strategy breaks down like a house of cards, but that is what happens.

Alright man, time to drop this. You've gone too far out on a limb here. To say placing speakers close to the front wall is "a poor mans solution" is equally wrong and absurd. Stuart's strategy of placing the speakers in the wall or tight with the wall isn't his own, nor is it rare or new. It's a typical recommendation made by people who understand SBIR and the simple physics involved. The most difficult issues to solve in a room are LF issues. That's why people like myself, Stuart, and any number of other people who do this for a living make design decisions which prioritize solving the low end first. It's a pretty simple concept here. It's a hell of a lot easier to treat issues at 200hz than at 60hz. No one here is advocating placing your speakers tight with the wall and then not treating your room.

I get it. You had a bad experience in your limited set of circumstances. But you should check yourself and realize you've been arguing with someone who has experience with hundreds more rooms than you have and does this for a living.

Adhoc 17th August 2019 04:35 PM

@ Northward , When you write "shell front wall" in the above post, from the picture I presume you mean the visible wall, seen from inside the room. Correct? (I usually refer to "shell walls" as those which are heavy and rigid behind the visible inner walls which may have various acoustic treatments.)

JayPee 17th August 2019 04:48 PM

@ Northward , any particular reason(s) speakers have not been flush mounted in this room? Space constraint?

Synthpark 17th August 2019 05:49 PM

Quote:

Originally Posted by Northward (Post 14153928)
Considering that the acoustic treatment in the room is well planned and equal in both scenario:

- if your studio has a properly shaped shell front wall 30°-0°-30° such that at sweet spot with speakers against the wall (and perpendicular to the wall) your are effectively in a quasi minimum phase SBIR scenario, the effect of speakers against front wall cannot have a negative effect on stereo and depth perception, and should in fact greatly enhance it. If the speakers are quite small, their Omni response / edge diffraction may be pushed higher in frequency and affect depth perception negatively. Not stereo. So beware of speaker choice.

- if your are dealing with a flat front wall (not shaped): depending on speaker size, while in general it should still be beneficial to stereo image it can in certain scenarii create negative first (and second) order reflections that have a negative influence. While possible, it is unlikely. Again, speaker size / edge diffraction /polar pattern plays a big role in that.

The secret is shell shaping to optimise quasi minimum phase response.

The last studio we did that way is this one:

Hi, although I was not referring to shaped shell fronts , it seems that your statements (also for the second part) go into a similar direction, at least not to deny that speaker size and directivity can play a big role and can potentially degrade depth perception, not blaming the room, but the front wall.

Whereas you seem to distinguish between "stereo" and depth, I was using the term "stereo" as it was originally defined (merely an abbreviation of stereophony) which includes all spacious techniques dealing with panning and depth, so if there is a negative effect on the depth perception, it is a negative effect on the "stereo image". :)

https://en.wikipedia.org/wiki/Stereophonic_sound

The German version clearly points to spaciousness.

https://de.wikipedia.org/wiki/Stereofonie

Northward 17th August 2019 07:01 PM

Quote:

Originally Posted by Adhoc (Post 14154243)
@ Northward , When you write "shell front wall" in the above post, from the picture I presume you mean the visible wall, seen from inside the room. Correct? (I usually refer to "shell walls" as those which are heavy and rigid behind the visible inner walls which may have various acoustic treatments.)

Hey Adhoc!

Yes, it's exactly what I mean. In these designs, while this particular wall has varying density/mass to manage/compensate LF boost from the quasi flush-mount it is partially load bearing and hard, so indeed a shell wall. It closes a cavity meant to manage LF SBIR.

Quote:

Originally Posted by JayPee (Post 14154269)
@ Northward , any particular reason(s) speakers have not been flush mounted in this room? Space constraint?

The client absolutely wanted to keep these. And they can't be mounted in-wall.

It works just fine, but there are design variables difficult to control, in particular the speakers bit. These speakers behaved well and the brand published honest and clear data that I could fully rely on while designing the room.

It's sadly seldom the case and to reach the FTB quality and performance benchmarks I can't rely on often much exaggerated or manipulated data - although more often than not the problem is that there simply isn't any available data outside FR... But a lot of hand waving and posturing from manufacturers. Which down the line doesn't answer any of my questions and I can't move forward.

These builds had also a few disadvantages compared to full in-wall: they were more expensive to build as the front wall is more complex / tedious, speaker decoupling not quite as performant and they are still subject to a few very minor downsides due to residual cabinet edge diffraction. They can't support full glass front walls. Design fee was also higher due to having to spend a lot more time on front wall design and chasing data from speaker manufacturers.

In one nightmare case I had to wait 4 months and have friends also in the Pro Audio industry help pull a lot of strings for me to finally, under a crazy NDA, see more than a FR plot. And the speaker response was a total mess, which prompted me to remove any guarantee on results and cancel the FTB certification. The client finally came to his senses and agreed to drop these and move to a full in-wall ATC setup. He never regretted that move and we still joke about these events years after.

As time went by and experience built up, in the early 2010s' I realized that in the end very few speakers were actually usable that way in a studio setting if I were to provide rooms consistently at a very high quality and reproductible standard. Less than I have fingers on my right hand.

Having constant conversations with engineers about this or that esoteric speaker was also getting a bit tiring after a while - especially with HiFi brands - as I knew at that point that most of them simply buy OEM drivers and put them in a nice looking box. That's why pushing them to visit in-wall studios we'd designed before any design contract was to be signed helped us show them the differences and what to expect from each setup. Which eventually lead to all our rooms being 100% in-wall, and overwhelmingly equipped with ATC.

So why bother offering a design topology that is more expensive, yet risky and complex to process, while proper in-wall is safer, 100% predictable, cheaper and will always outperform it on all counts. So I dropped the quasi-flush mount designs in 2012.

This one is the last of these I ever designed - about 8 years ago iirc. These days if you want a FTB room, it's full in-wall no discussion possible.

Quote:

Originally Posted by Synthpark (Post 14154490)
Whereas you seem to distinguish between "stereo" and depth, I was using the term "stereo" as it was originally defined (merely an abbreviation of stereophony) which includes all spacious techniques dealing with panning and depth, so if there is a negative effect on the depth perception, it is a negative effect on the "stereo image". :)

OK - thanks for clarifying. I very much distinguish depth and stereo while discussing listening experiences as it allows clarifying if you're talking about Width or Depth of field.

Although they are indeed linked.

Synthpark 18th August 2019 11:59 AM

Quote:

Originally Posted by nms (Post 14153932)
Alright man, time to drop this. You've gone too far out on a limb here. To say placing speakers close to the front wall is "a poor mans solution" is equally wrong and absurd. Stuart's strategy of placing the speakers in the wall or tight with the wall isn't his own, nor is it rare or new. It's a typical recommendation made by people who understand SBIR and the simple physics involved. The most difficult issues to solve in a room are LF issues. That's why people like myself, Stuart, and any number of other people who do this for a living make design decisions which prioritize solving the low end first. It's a pretty simple concept here. It's a hell of a lot easier to treat issues at 200hz than at 60hz. No one here is advocating placing your speakers tight with the wall and then not treating your room.

I get it. You had a bad experience in your limited set of circumstances. But you should check yourself and realize you've been arguing with someone who has experience with hundreds more rooms than you have and does this for a living.

ok ok

Lets assume you have a smaller nearfield speaker (focal solo be class). How do you want treat a dip at 500 Hz arising from the front wall in any other way but the front wall causing the problem? (if it is not accidently compensated with other reflecting surfaces like ground, mixing desk or table). Because you want to solve it electronically?

I called it "poor mans solution" because: why don't you place the speakers a little apart from the front wall and place a high performance thin absorber between speakers and wall? Take, as a "Cadillac solution" a VPR for example, from Renz. It goes from 60 Hz all up and with 10 cm quite a thin layer. A cost issue? Or take any other solution, thicker. Why the speakers near the wall (flush mounted is a whole different thing)?

http://www.renz-solutions.de/produkt...nator-vpr.html

Yout are talking about "low end" all the time and still don't consider the lower mid range coloration.

For example a mono speaker in the center (a little simplified math):
with 40 cm between woofer and wall you get something like

- half wavelength distance: dip at 4x40cm corresponds to f = (340m/s)/(4x0.40m) = 212 Hz
- 1 and a half wavelength distance: dip at (340m/s)/(4/3x40cm) correponds to 637 Hz
- and you get an additional increase at one wavelength correspoding to (340m/s)/(2x0.4m) = 425 Hz.

based on approximated dip frequency wavelength L = (2 x d)/(n+1/2) for woofer-wall distance d and n=0,1,2,3...

Again I am talking about smaller nearfield speakers, no mastering grade big three-way systems with bigger chasseys. I presented some measurements you find on the net from serious tests which show that back attenuation is far from sufficient for such smaller speakers, and even for the 310 it is not enough.

As a side note: I didn't say you cannot do it, I guess you have a good way to treat this problem, because you are doing this for a living and know these things better than me. So am just very curious how you want to solve this isse. :)

nms 18th August 2019 01:30 PM

Quote:

Originally Posted by Synthpark (Post 14155553)
You are talking about "low end" all the time and still don't consider the lower mid range coloration.

How many times do you need it repeated? Please pay attention. As mentioned previously, you "use absorption between the speakers to deal with what remains".

Quote:

Lets assume you have a smaller nearfield speaker (focal solo be class). How do you want treat a dip at 500 Hz arising from the front wall in any other way but the front wall causing the problem? (if it is not accidently compensated with other reflecting surfaces like ground, mixing desk or table). Because you want to solve it electronically?
Solve a dip at 500hz electronically? Where are you getting this from?
Quote:

I called it "poor mans solution" because: why don't you place the speakers a little apart from the front wall and place a high performance thin absorber between speakers and wall? Take, as a "Cadillac solution" a VPR for example, from Renz. It goes from 60 Hz all up and with 10 cm quite a thin layer....
:facepalm:

A VPR does not offer broadband absorption. It's a tuned panel. It doesn't go "from 60hz all up". You are very.. VERY.. confused. Problems at 500hz are dealt with very easily using porous broadband absorption.

I'm not sure how much simpler this can be broken down to explain to you.

1. Place speakers close to the wall in order to avoid creating problems that are far more difficult to treat.

2. Use broadband absorption on the front wall between the speakers in order to treat the remaining interference caused by the front wall and the deficiencies in your room.

Based on what you've just said I'm going to assume you've never used a VPR or measured its effect in a room. It's about as much a "cadillac solution" as a torx head screwdriver is. A torx screwdriver works great if you need to undo a torx head screw, but not very useful for removing a flat head screw.. or sawing a board in half for that matter.

Please drop this and stop trying to suggest things you have no experience with to solve a simple issue which was covered multiple times over. It's not a productive use of anyone's time.

I suggest you take a day to explore and educate yourself on this first hand. Set your speakers up close to the wall and take some measurements with and without broadband absorption placed directly adjacent to the speakers (between them) and also with speakers pulled away from the wall. Then you will have a better understanding of the reality here.

Synthpark 18th August 2019 06:18 PM

5 Attachment(s)
Quote:

Originally Posted by nms (Post 14155633)
How many times do you need it repeated? Please pay attention. As mentioned previously, you "use absorption between the speakers to deal with what remains".

Solve a dip at 500hz electronically? Where are you getting this from? :facepalm:

"Elektronically" means using EQ, not some acoustic treatment, isnt that clear? :facepalm:

Ok you are saying using an absorber between the speakers, in the middle of the front wall. That's interesting, something new.

Does it work for 600 Hz? How near do you want to place the absorber to the speakers? Do you make it so thick that it will absorb from the side (see diagram)? What if the reflected wave just ignores it and bounces off the wall, diffracts and hits the listener?

Quote:

Originally Posted by nms (Post 14155633)
A VPR does not offer broadband absorption. It's a tuned panel. It doesn't go "from 60hz all up". You are very.. VERY.. confused. Problems at 500hz are dealt with very easily using porous broadband absorption.

Well, I meant actually this module, BKA. The VPR is quite broadband, as you see, but not at 500 Hz anymore. The BKA is broadband enough to cover all relevant frequencies above 100 Hz for typical speaker to front wall distance.

I must admit, I am even more confused now.

Absorbers on the front wall

Glen Kuras recommends absorbers behind the speakers, you suggest in between, that't a new approach.
Maybe a secret way of successfull treatment?

Brian M. Boykin 18th August 2019 07:24 PM

Quote:

Originally Posted by Synthpark (Post 14155991)
Absorbers on the front wall

Glen Kuras recommends absorbers behind the speakers, you suggest in between, that't a new approach.
Maybe a secret way of successfull treatment?

I’ve read this very thread in my studies (you asked about my education) and Glen and all the others start off with the word “if” in their replies in that thread. Meaning “if” you still have issues after treating the entire room properly “then” you can try absorption on the front wall behind the monitors. It’s the last step in a long process. Room treatment is a process and if you read these pages it’s almost algorithmic. The people your arguing with have laid out a very easy to understand process for achieving the best, or “least worst as I say” possible acoustics for a small room (decided by volume). I’ve been reading Glens advice as well as Ethan’s for 20 years now. They have data they’ve compiled over that 20 years that reads like a book. If your starting on page 300 of a 350 page book you’ll be lost. Your understanding of what he’s saying is taken out of context in the grand scheme of his advice derived form his 20+ years of studying acoustics.

nms 18th August 2019 11:35 PM

Quote:

Originally Posted by Synthpark (Post 14155991)
"Elektronically" means using EQ, not some acoustic treatment, isnt that clear? :facepalm:

It's clear as day, which is why I asked "Where are you getting this from?". None of us are suggesting EQ to deal with SBIR. You can easily deal with 500hz using broadband absorption.

Quote:

Ok you are saying using an absorber between the speakers, in the middle of the front wall. That's interesting, something new.
Does it work for 600 Hz? How near do you want to place the absorber to the speakers? Do you make it so thick that it will absorb from the side (see diagram)? What if the reflected wave just ignores it and bounces off the wall, diffracts and hits the listener?
Thick absorption between the speakers is not a new or secret approach. It's what we get when doing a soft (absorptive) flush mounted speaker wall.

If you pull the speaker away from the wall, you add delay to the front wall reflection, causing the problems to become lower in frequency and harder to treat. Keeping them closest to the massive boundary (wall) will do the opposite. You need to consider the reflection path involved with what leaves the speakers, bounces off the wall, then hits the listening position. The area reflecting the sound which arrives at listening position is between the speakers. And yes, ideally it's good to keep the sides of this absorption panel (the area adjacent to the speakers) vented sufficiently for additional absorption. How thick to make the panel depends on your circumstances. A thicker trap there will also help your room's front to back axial mode.

Synthpark 19th August 2019 09:48 AM

Quote:

Originally Posted by nms (Post 14156394)
It's clear as day, which is why I asked "Where are you getting this from?". None of us are suggesting EQ to deal with SBIR. You can easily deal with 500hz using broadband absorption.

Thick absorption between the speakers is not a new or secret approach. It's what we get when doing a soft (absorptive) flush mounted speaker wall.

If you pull the speaker away from the wall, you add delay to the front wall reflection, causing the problems to become lower in frequency and harder to treat. Keeping them closest to the massive boundary (wall) will do the opposite. You need to consider the reflection path involved with what leaves the speakers, bounces off the wall, then hits the listening position. The area reflecting the sound which arrives at listening position is between the speakers. And yes, ideally it's good to keep the sides of this absorption panel (the area adjacent to the speakers) vented sufficiently for additional absorption. How thick to make the panel depends on your circumstances. A thicker trap there will also help your room's front to back axial mode.

You are talking like I have never heard of flush mounted speakers.
I have several times in this thread written that "flush mounting is a different story".

soft flush mounting speakers - how to do correct?

So just to make shure: do you mean real flush mounting or not, that is building the speaker into an absorber?

I dont think the thread starter had this in mind.

Quote:

Originally Posted by gedna (Post 14141642)
Hello all

i got an empty room ( front wall height is 2.3m room is 3 meters wide and the lenght is 4.9 meters)

What is the best placement of monitors and the table..

I have read quite a lot, and i understand the best monitor position in this small'ish room is as close to front walls as posible ( i have a window in front wall)

How close? i will put acoustic treatment soon (bass traps in all 4 corners with air gaps, and first reflections and maybe the ceiling)

Regarding 38percent rule, my monitors is about 80-90cm away from the wall, so i have to move my listening position closer...

Yes i will buy sonarworks XREF20 mic and measure with REW

But for now im really interested in your opinions

Flush mounting means high effort and high experience. There is a window in the room. Nobody asks where the window is, how big the window is.

Flush mounting reduces the choice of speakers.

There is no way you gonna flush mount this high end, popular speaker:

https://barefootsound.com/category/spotlight/page/4/

And what about rear-ported speakers for flush mounting? Bad idea, isn't it?

So if I was a professional, I would ask:

- whats your budget?
- what are your speakers?
- how much effort are you planning?
- is it worth to make long-term investments in this room?

And if flush mounting is no option (and likely it is not), then what to do?

You can only place either the speaker directly at the wall (what the thread starter believes is best practise), OR you place the speaker a little apart and place absorbent material at the wall to reduce SBIR.

And if your absorbent material is doing fine and you dont have a problem to absorb between 100 and 200 Hz, but also higher, covering lower mid range as well, then it seems to me that this solution should perform better, unless you prove me wrong, because "traditional" flush mounting is likely to be out of question here.

Regarding SBIR and EQ: although I dont like EQing (for idealized reasons), if anything can be treated with EQ, it would be SBIR, since SBIR does not have reverberation, it is a (filtered) one-time delay in the impulse response.

And to give you an idea of my way of thinking: although EQing may help (if the dips can be handled without pushing high-Q peak filters), if the stereo image (depth perception) suffers from the wall, the EQing will most problably not help, so no option for me.

nms 19th August 2019 12:43 PM

Quote:

Originally Posted by nms
I'm not sure how much simpler this can be broken down to explain to you.

1. Place speakers close to the wall in order to avoid creating problems that are far more difficult to treat.

2. Use broadband absorption on the front wall between the speakers in order to treat the remaining interference caused by the front wall and the deficiencies in your room.

Quote:

Originally Posted by Synthpark
you are saying using an absorber between the speakers, in the middle of the front wall. That's interesting, something new.

Quote:

Originally Posted by nms
Thick absorption between the speakers is not a new or secret approach. It's what we get when doing a soft (absorptive) flush mounted speaker wall.

Quote:

Originally Posted by Synthpark (Post 14156882)
You are talking like I have never heard of flush mounted speakers.
I have several times in this thread written that "flush mounting is a different story".

So just to make shure: do you mean real flush mounting or not, that is building the speaker into an absorber?

I dont think the thread starter had this in mind.

:facepalm:

Haha.. I'm getting off this infinite loop. I just can't do it.

Synthpark 19th August 2019 01:50 PM

Quote:

Originally Posted by nms (Post 14157104)
:facepalm:

Haha.. I'm getting off this infinite loop. I just can't do it.

Yeah this gets too harsh by ignorant people like you.
But look what I just found: An article from 2016.

https://www.soundonsound.com/sound-a...near-rear-wall

Quote:

One down side of placing the speaker very close to the back wall is the effect it has on stereo imaging and the perceived depth of the soundstage. In general, the further the speaker is from the back wall, the greater the impression of soundstage depth becomes. So there are lots of interacting aspects of the overall in-room speaker performance that have to be balanced — compromises are inevitable.
Yeah there is an author with the right ears to notice these things.

Take care!

nms 19th August 2019 02:24 PM

Quote:

Originally Posted by Synthpark (Post 14157211)
Yeah this gets too harsh by ignorant people like you.

The problem is you just don't listen, and as shown in my quotes above you take very simple statements and find ways to take them in a wrong direction and create unnecessary confusion.

Quote:

But look what I just found: An article from 2016.
https://www.soundonsound.com/sound-a...near-rear-wall
Yeah there is an author with the right ears to notice things others, who want to be acousticians, just seem to ignore, because all they know are their REW figures.
I'm not at all surprised that you've found more material to misinterpret and confuse yourself with. How many time does it need to be explained to you before you will understand the solution? I'll repeat it for you one last time:

Use broadband absorption on the front wall between the speakers in order to treat the remaining interference caused by the front wall and the deficiencies in your room.

If you don't do that and your room is insufficiently treated then of course you're going to have problems. What do you expect? Sort it out mate. Inexperienced people get tripped up on this all the time, but the correct solution to many things in the world of acoustics depends on SPECIFIC CIRCUMSTANCES. You can't just ignore the circumstances and blindly follow something you read online then expect it will apply to your room.

Synthpark 19th August 2019 02:29 PM

Quote:

Originally Posted by nms (Post 14157277)
Use broadband absorption on the front wall between the speakers in order to treat the remaining interference caused by the front wall and the deficiencies in your room.

If you don't do that and your room is insufficiently treated then of course you're going to have problems. What do you expect? Sort it out mate.

Hey mate,

I asked you if you mean real flush mounting. Where is the answer?

Please show me a photo of your solution!