Fabric doubling question

[pauloticks]

Hello friends,
I have a question about some DIY panels I made.
I covered them in an inexpensive breathable fabric called
homespun 100. I did them all in black as I thought it
would be a nice change from the burgundy ones I had
up before (the new ones are thicker). Well now I have
decided the black doesn't look as nice and want to do them
in burgundy as well but I am unable to take the old fabric off
without ruining the 703. I adhesive glued the fabric to the 703
and stapled it to the frames. I was wondering if I could just add
another layer of burgundy fabric over the black without fear
of loosing some of the absorption qualities of the panels. Thank
you everyone so much for your help and I hope you're having a
great day!!!

[SAC]

You will want to replace the material.

Except for the additional step of removal, it should not be any more difficult than what you are proposing.


Edit as some are confused by the above suggestion:

The above is predicated on the statement that "I am unable to take the old fabric off
without ruining the 703."

This is not the case with light non-bridging adhesives, but it is a common characteristic of bridging 'glues' that are neither easily separated and which decidedly have a negative impact on the absorption of porous material.

[pauloticks]

SAC,
Thank you for your reply.
I am unable to remove the fabric
without ruining the 703 as I have
adhesive glued the fabric to them.

[jhbrandt]

Yes. Actually, the glue changes the absorption characteristic of the rock wool & fabric combo...

Don't put any glue on the face of the panels unless you want them more reflective.

Cheers,
John

[SAC]

As John has so correctly observed, the way you have configured them has already 'ruined' their absorptive performance.

In order to try to salvage them, you will want to carefully remove the cloth from the surface, in the process removing the (hopefully) thin layer of material bridged with adhesive!

Then recover them without the use of adhesives. Staples are quite sufficient to hold the cloth to the frame and panel.

[pauloticks]

Originally Posted by SAC

As John has so correctly observed, the way you have configured them has already 'ruined' their absorptive performance.

OH NO!!!! That's terrible news! I wonder if I should just start over
again with new panels. Thank you again for all the help!

[SAC]

Originally Posted by pauloticks

OH NO!!!! That's terrible news! I wonder if I should just start over
again with new panels.

You can if you want...

Or you can follow the earlier suggestions designed to salvage them!

Remove the material and the thin layer of fiberglass impregnated with glue.

I would then turn that surface to the rear of the panels (in the leap of faith that any residual bridging might act as a quasi- FRK membrane - hey, one can fantasize! Or baring that, at least it will not be as effective as a reflective surface!) and stack another layer of OC703 on top to bring the total thickness to 4" and re-cover. You will need a new deeper frame.

[latestflavor]

Originally Posted by SAC

As John has so correctly observed, the way you have configured them has already 'ruined' their absorptive performance.

is there any data to support this?

i find it hard to believe anything but hi freq's are affected, which considering how dead the average home broadband diy'er rooms are wouldn't be the be the end of the world.

[SAC]

Yeah, the industry runs exhaustive tests to verify performance data related to the inappropriate application of materials.

Bear with me as we are in the middle of testing the effects of ingesting formalin and K-1 kerosene to evaluate the effects on weight loss and insomnia. And we are still waiting on the results of the long term study evaluating the health effects of stuffing unlit cigarettes into the ears... My gut says the ramifications of the results will be devastating...


Just like with painting foam, by applying a medium that "bridges" the porous structure of an open celled material, you lower the degree of porosity and permeability, which, if you are familiar with how porous absorption 'works', lessens the absorptive quality of he material, thus resulting in an increase in the resistive component of the acoustical impedance resulting in increased reflectivity.

This is also why painting or printing on the fabric covering of porous panel absorbers reduces the effectiveness of the absorber by virtue that the paint bridges the porous surface structure thus blocking pathways. That is why a process such as dye sublimation that dyes the material filaments themselves without bridging is employed for panel printing (and why companies such as GIK properly utilize the method).


Not only is there absolutely no data to support this, the very nature of how porous absorption, which accounts for this behavior, is completely beyond the scope of modern physics. Thus you will just have to trust us - or believe whatever you like. Its your choice. On the other hand, if you do not find reading too objectionable, one source of information is the D'Antonio & Cox Acoustic absorbers and Diffusers. But beware, I understand that one of those fellows is a foreigner... And you burn any pages at your own peril...

[pauloticks]

I made mine the same ways as this fellow but I sprayed
some adhesive on the front as well for the cloth to stick to.
I am not sure if when I said glue it might have been mistaken
for a thicker glue. Sorry for any confusion and thanks again friends!!!
http://www.youtube.com/watch?v=-Lc0BjFHoA8

[SAC]

If the adhesive was a 'simple' non-bridging product like 3M spray adhesive, there is no problem removing adhered material and the entire issue is a non-starter!

Just remove the cloth!




Edit just for clarity and completeness:

In this case we were lucky as the adhesive was a very light non-bridging type.

In any case, if one does not seek to modify the absorptive quality of a porous material, one does not want to ever simply apply a thicker, bridging type of material (any material) like an Elmer's style glue, paint, printer's ink, etc, that will bridge between fibers and reduce permeability and tend to skin the material. This most definitely reduces absorption of he material, especially in the mod and high frequencies.

[pauloticks]

Thanks SAC will do!!! I appreciate all the guidance. You
have all been fantastic and a great help!

[latestflavor]

Originally Posted by pauloticks

have all been fantastic and a great help!

that is one man's opinion.

[SAC]

Originally Posted by latestflavor

is there any data to support this?

i find it hard to believe anything but hi freq's are affected, which considering how dead the average home broadband diy'er rooms are wouldn't be the be the end of the world.

LOL!

Let's see, so such astute insight maintains that in a small room that has been over-damped to the degree that the high frequencies are missing - PRESUMABLY as a result of the indiscriminate overuse of such absorptive devices as broadband absorbers for which a bridging substance would impair high frequency absorption - that using an ineffective absorber that properly is used to absorb high gain destructive specular reflections is not a problem.

Really, so now destructive specular reflections are OK!? And the overuse of absorption to simply absorb non-critical energy - well, that's fine too - especially as it apparently serves as an excuse to ignore the real specular reflections which create real problems.

I am sorry that the proper use of absorption to surgically address either anomalous modal or specular issues while not overdamping a small room is apparently so confusing.

Likewise, if a broadband panel's use is appropriate to absorb such localized targeted energy, how the improper use of bridging substances, be they paint, ink, glue, or any other substance can serve a detrimental purpose further limiting the effectiveness of a treatment whose specific purpose should be to strategically address those very issues.

The irony is that this subject is actually very simple, unless one makes erroneous assumptions and then compounded them by positing that inappropriate surface agents make no difference as the fundamental use of treatments has not been performed properly from the start.

But its always useful(sic) for someone to hold up cases of the improper use of treatments compounded by the further misuse of treatments in an attempt to discredit the proper and appropriate strategic use of treatments.

We can hardly wait for additional insights...

[latestflavor]

sac, you have already been counterproductive in this thread. you have already done a 180, tried to snark your way out of it through endless pontification, and spew insult - basically the usual you.

the kid's absorbers were ruined - oh no. but wait, he was lucky to use the double secret glue that 99.9% of all DIYer's use on their fiberglass. Whew, thank the queen you have saved the day. Thanks SAC! Another pontification success.

now carry on, go back and edit your posts as you have already done and continue to pick fights where they are not necessary.

We're all on the edge of our chairs.

[SAC]

No 180 at all!

Both scenarios described are valid.

The OP first stated that the "glue" used to adhere the fabric was such that it could not be removed without significant damage to the substrate, implying that the adhesive was a much more substantive type - which tend to be bridging. Such cannot be easily removed. And a bridging substance substantially changes the nature of the absorptive material.

But then, you are about the only one here who is ignorant of this fact.

However, we then later discovered that only a light contact adhesive had been applied which is not a bridging substance was correct, and as such fabric so attached with such adhesive can be relatively easily removed.

I am sorry that you are so easily confused.

And as we noted, both cases are valid - once one is able to provide an accurate identification of the adhesive employed.

[latestflavor]

To paulotics:

Broadbands are like machetes. Most of the time is not always what you need, but its cheap and easy and you get a large range of absorption in a hurry.

I can almost guarantee if you take 10 measurements at your mixing desk, add a second layer of fabric to your absorbers, the difference will not be practically significant. Not to those of us on earth anyways. Compared to all the other factors involved that weren't mentioned or asked, there are so many more choices much more than second guessing a second layer of fabric and how it will change the gas flow absorption properties of rigid fiberglass. Tuning a room is far from 100% science and your other choices will obliterate this.

[SAC]

The ral world impact of the multiple layers will be that reflection will increase with angle.

the significance of that is that as most energy does not impact an absorber at a normal (90 degree perpendicular angle), that part will be absorbed, but another part will be reflected - with the amount reflected increasing as the angle increasingly differs from 90 degree.

As we are generally dealing with reducing specular reflections in the initial signal delay gap, making sure that the reflected energy is ~20 dB SPL below the direct energy is important. And a reflection typically will not reduce the gain of a reflection more than ~ 6 dB - thus you need all the efficiency of the absorber you can get.

The practical result, many installations despite using what they think are effective broadband absorbers, sill have destructive energy impinging upon the listening position and creating destructive interference.

THAT is why we worry about doing this stuff right and actually attempt to deal with REAL WORLD variables that affect REAL WORLD performance that some simply dismiss.

[latestflavor]

painting pin heads on the broad side of a barn

i've added a second (and third) layer of muslin to my traps before, it didn't make the least bit of difference.

people who spew facts from textbooks should be able to back it up with a real experience.

cards on the table

[Rod Gervais]

Originally Posted by latestflavor

painting pin heads on the broad side of a barn

i've added a second (and third) layer of muslin to my traps before, it didn't make the least bit of difference.

people who spew facts from textbooks should be able to back it up with a real experience.

cards on the table

I would be interested in seeing the 3 sets of tests that you preformed after the initial setup - and each of the subsequent changes you made..... not the "least bit of difference" while not quantitative is certainly suggestive of "no change at all"...... and that makes no sense whatsoever....

Rod Gervais
Director of Education
GIK Acoustics
Gik Acoustics USA
Gik Acoustics Europe
Tel.(US)1.888.986.2789
Tel.(UK)+44(0)20.7558.8976

[Rick Sutton]

Man, I know I should stay out of this but here goes.
My 40 plus years in the studio game leads me to say latestflavor has the best handle on this situation.
The thing that is starting to bother me in these acoustic threads is the overload of reliance on academic bludgeoning and just plain outright disrespect shown by several of our "learned colleagues" to argue their points.
In one thread the academics argue that their is no "effective" difference in a hard surface made out of different materials......you know, the old wood floor/glass floor type of debate. But in this thread our experts tell us that a little extra fabric (possibly a very light one, who knows?) is going to be a real problem when added to a DIY panel already covered in fabric. I, and others will argue that there is no "effective" difference in this situation.
I realize that most of the experts here are just trying to help but I sense one or more are just trying to exercise their academic chops and don't have a real handle on the application of all their knowledge.
Spare me the explanations. I've been to university too. Studied architectural acoustics in the dark ages. I'm sure it has changes and evolved....to a point. But I've heard the differences of adding additional fabric in this type of situation many times and they are not "effectively" a big deal. I've probably spent more hours in............never mind, I'll spare you all my gory details.
I'll leave you to your scientific analysis of this "o' so complex" situation. Just remember, we're not talking a symphony hall here. There is actually an effective difference, you know, between a symphony hall and a small space with some DIY panels.....yes, I know you know.......just sayin'.

Rod, my post just happens to be directly under yours, it is not specifically a response to yours. My rant stems more from a recent situation of interesting threads on acoustics unfortunately turning into useless information argue fests loaded with red-herrings from both "camps".

[SAC]

Originally Posted by Rick Sutton

Man, I know I should stay out of this but here goes.
My 40 plus years in the studio game leads me to say latestflavor has the best handle on this situation.
The thing that is starting to bother me in these acoustic threads is the overload of reliance on academic bludgeoning and just plain outright disrespect shown by several of our "learned colleagues" to argue their points.
In one thread the academics argue that their is no "effective" difference in a hard surface made out of different materials......you know, the old wood floor/glass floor type of debate. But in this thread our experts tell us that a little extra fabric (possibly a very light one, who knows?) is going to be a real problem when added to a DIY panel already covered in fabric. I, and others will argue that there is no "effective" difference in this situation.
I realize that most of the experts here are just trying to help but I sense one or more are just trying to exercise their academic chops and don't have a real handle on the application of all their knowledge.
Spare me the explanations. I've been to university too. Studied architectural acoustics in the dark ages. I'm sure it has changes and evolved....to a point. But I've heard the differences of adding additional fabric in this type of situation many times and they are not "effectively" a big deal. I've probably spent more hours in............never mind, I'll spare you all my gory details.
I'll leave you to your scientific analysis of this "o' so complex" situation. Just remember, we're not talking a symphony hall here. There is actually an effective difference, you know, between a symphony hall and a small space with some DIY panels.....yes, I know you know.......just sayin'.

Did they teach you in school in your vast experience to accurately represent the nature of events of which you choose to recount?

“In one thread the academics argue that their is no "effective" difference in a hard surface made out of different materials......you know, the old wood floor/glass floor type of debate.”

And I am sorry that you , like several others who are apparently not familiar with the complexities of acoustic behavior and as such declare anything with which they are not familiar as meaningless , that your description likewise fails to distinguish between basic reflectivity and the character of that which is reflected. And for you folks, to use the electrical analog, a resistor is a capacitor is an inductor! Right? They can all offer similar resistance. But you mean there are differences in how that resistance manifests itself in a system? They can all resist ‘equally’, but you mean they exhibit different characteristics as a function related to that resistance. Yup, I know it’s so confusing. Especially when one cannot distinguish - and apparently have no means to distinguish, between the various characteristics that fall under your gross generalization that they either all reflect, or they all behave differently. Things sure are simple in the flatland!

Fact: they can both be considered equally reflective (as you are oh so focused on practicality) while at the same time imparting distinctly different characteristics to the perceived space. Just as a resistor, a capacitor and an inductor can all exhibit essentially the same resistance, yet impart radically different net behaviors within the context of a circuit.

But since “we’re not talking a symphony hall here. There is actually an effective difference, you know, between a symphony hall and a small space with some DIY panels.....” we most certainly wouldn’t want to try to begin to understand how this subject is not quite as simple as choosing one of those two absurd generalizations. The real irony is that the small room environment is the more difficult of the two environments to optimize- precisely why such issues become more important! Oh…but hey, its jut the old “the old wood floor/glass floor type of debate”.

And as far as reflections off materials otherwise ASSUMED to be completely absorbing and which make little difference – especially as we are dealing with their performance in the near field in a small room – that place that is not a symphony hall where one listens in the far field and where air absorption plays a significant role. And where in a small room one must artificially establish an ISD that is NATURALLY occurring in a symphony hall! So why would reflections off the surface of an “absorber” matter???

And of course, the salient: “I've heard the differences of adding additional fabric in this type of situation many times and they are not "effectively" a big deal.”

You may have spent allot of time in a studio, but apparently you have not spent much time measuring or understanding the dynamics of absorptive panels. But hey, since I haven’t a clue, I know someone who does:

“In practice, absorptive materials are often placed on walls where the sound is almost always at "grazing" incidence, or nearly parallel to the surface. When you drop a rock into the water it sinks, but when you throw it parallel to the water, it will sometimes skip along the surface. Sound behaves in much the same way: many materials which appear "transparent" based on NRC ratings or porosity are actually highly reflective to sound at grazing incidence. One example is perforated metal, which frequently is incorporated into pre-fabricated modular acoustical enclosures to provide an "absorbent" interior surface. If a modular room is shaped to provide a reflection-free zone (RFZ) for a specific listening area, or if loudspeakers are mounted near the perforated metal surfaces, sound will strike the surface at grazing incidence and the absorptive properties will be rendered much less effective than intended.” RBDG

And to think some people pay them for such nonsensical insight.

But I must remember, we are dealing with only small rooms here in the near field of an absorber where the specific application is generally to specifically create an ISD/RFZ space where we need the reflections be reduced by ~20 dB SPL or more! So why would ANYONE assume such behavior to be substantial? After all, it’s not a symphony hall where such behavior is not at issue...

And the really funny thing: this behavior can be explained causally. But why should we go there and attempt to actually explain the hows and whys of such behavior. After all, we’re only dealing with small rooms and with folks whose setups really don’t matter. And the folks here are all such insignificant folk - is it really worth the attempt to explain such behavior anyway? Right?

So, to make things simple for you an the few others for whom the world is a very simple place:

One: Applied properly, wood and glass and cement do not reflect with any significant differences in terms of the amount of energy reflected. (And, they do not necessarily, but CAN, exhibit qualitative differences for reasons other than what determines the basic reflection of such energy!)

And two: Treatments that modify the permeability of a surface, be they in the form of bridging substances such as paint, printer's ink or glue, or in the form of material coverings can indeed negatively alter the effectiveness of absorptive media in significant manner - ESPECIALLY in the near field of the unit.

And for the the rest of you 'who are not dealing with symphony halls': things are as you believe them to be; and hell, it really doesn't matter anyways. Now you can return to your blissful lives and go back to sleep. Sorry to have woken you.

[Rick Sutton]

Originally Posted by SAC

Did they teach you in school in your vast experience to accurately represent the nature of events of which you choose to recount?

“In one thread the academics argue that their is no "effective" difference in a hard surface made out of different materials......you know, the old wood floor/glass floor type of debate.”

And I am sorry that you , like several others who are apparently not familiar with the complexities of acoustic behavior and as such declare anything with which they are not familiar as meaningless , that your description likewise fails to distinguish between basic reflectivity and the character of that which is reflected. And for you folks, to use the electrical analog, a resistor is a capacitor is an inductor! Right? They can all offer similar resistance. But you mean there are differences in how that resistance manifests itself in a system? They can all resist ‘equally’, but you mean they exhibit different characteristics as a function related to that resistance. Yup, I know it’s so confusing Especially when one cannot distinguish - and apparently have no means to distinguish, between the various characteristics that fall under your gross generalization that they either all reflect, or they all behave differently. Things sure are simple in the flatland!

Fact: they can both be considered equally reflective (as you are oh so focused on practicality) while at the same time imparting distinctly different characteristics to the perceived space. Just as a resistor, a capacitor and an inductor can all exhibit essentially the same resistance, yet impart radically different net behaviors within the context of a circuit.

But since “we’re not talking a symphony hall here. There is actually an effective difference, you know, between a symphony hall and a small space with some DIY panels.....” we most certainly wouldn’t want to try to begin to understand how this subject is not quite as simple as choosing one of those two absurd generalizations. The real irony is that the small room environment is the more difficult of the two environments to optimize- precisely why such issues become more important! Oh…but hey, its jut the old “the old wood floor/glass floor type of debate”.

And as far as reflections off materials otherwise ASSUMED to be completely absorbing and which make little difference – especially as we are dealing with their performance in the near field in a small room – that place that is not a symphony hall where one listens in the far field and where air absorption plays a significant role. And where in a small room one must artificially establish an ISD that is NATURALLY occurring in a symphony hall! So why would reflections off the surface of an “absorber” matter???

And of course, the salient: “I've heard the differences of adding additional fabric in this type of situation many times and they are not "effectively" a big deal.”

You may have spent allot of time in a studio, but apparently you have not spent much time measuring or understanding the dynamics of absorptive panels. But hey, since I haven’t a clue, I know someone who does:

“In practice, absorptive materials are often placed on walls where the sound is almost always at "grazing" incidence, or nearly parallel to the surface. When you drop a rock into the water it sinks, but when you throw it parallel to the water, it will sometimes skip along the surface. Sound behaves in much the same way: many materials which appear "transparent" based on NRC ratings or porosity are actually highly reflective to sound at grazing incidence. One example is perforated metal, which frequently is incorporated into pre-fabricated modular acoustical enclosures to provide an "absorbent" interior surface. If a modular room is shaped to provide a reflection-free zone (RFZ) for a specific listening area, or if loudspeakers are mounted near the perforated metal surfaces, sound will strike the surface at grazing incidence and the absorptive properties will be rendered much less effective than intended.” RBDG

And to think some people pay them for such nonsensical insight.

But I must remember, we are dealing with only small rooms here in the near field of an absorber where the specific application is generally to specifically create an ISD/RFZ space where we need the reflections be reduced by ~20 dB SPL or more! So why would ANYONE assume such behavior to be substantial? After all, it’s not a symphony hall where such behavior is not at issue...

And the really funny thing: this behavior can be explained causally. But why should we go there and attempt to actually explain the hows and whys of such behavior. After all, we’re only dealing with small rooms and with folks whose setups really don’t matter. And the folks here are all such insignificant folk - is it really worth the attempt to explain such behavior anyway? Right?

So, to make things simple for you an the few others for whom the world is a very simple place:

One: Applied properly, wood and glass and cement do not reflect with any significant differences in terms of the amount of energy reflected. (And, they do not necessarily, but CAN, exhibit qualitative differences for reasons other than what determines the basic reflection of such energy!)

And two: Treatments that modify the permeability of a surface, be they in the form of bridging substances such as paint, printer's ink or glue, or in the form of material coverings can indeed negatively alter the effectiveness of absorptive media in significant manner - ESPECIALLY in the near field of the unit.

Thanks for that detailed reply SAC. I 'm not sure why you felt compelled to be so condescending and disrespectful. Even though I didn't quote you or reference you in my post. I had hoped for better things from you.

[SAC]

Veiled references and erroneous mischaracterizations of positions taken do not absolve your assertions.

And the fact is; given the time frame you cited, the tools were not available to quantify or qualify the characteristics to which we have referred and as such were NOT taught in schools. In fact many still have not incorporated the advancements.

Things have changed SUBSTANTIALLY in the acoustics world - at least in some places and for some on this forum.

And to imagine, we even know why the Bose direct -reflecting system, all the rage 40 years ago, is flawed. You see, things have changed!

[latestflavor]

is anyone certain someone is not posting from the sanitarium?

also, i have this creepy feeling that there is a schizophrenic delusion he believes he is british, but actually isn't.

besides the empty brow beating being trite and theatrical, he hasn't really said anything convincing other than the obvious.

luckily, there is the block and unsubscribe function.

what a tactless, creepy individual with little intellectual integrity and emotional stability.

its quite unfortunate for this forum.

[pauloticks]

and now back to my question hahaha.

Thank you everyone for your input!
I have covered over the panels with burgundy
fabric and then did the very "scientific" handclap
test. There does not appear to be more or less
flutter echo than with only one layer of fabric.
I am sorry that for all the confusion and debate I
have caused. Thanks again for everyones time and
enjoy the coming spring!!! I am putting up a new swing
set for my daughter so I know she will be enjoying it soon!

Best Regards,
Paul

[localhost127]

Originally Posted by pauloticks

and now back to my question hahaha.

Thank you everyone for your input!
I have covered over the panels with burgundy
fabric and then did the very "scientific" handclap
test. There does not appear to be more or less
flutter echo than with only one layer of fabric.
I am sorry that for all the confusion and debate I
have caused. Thanks again for everyones time and
enjoy the coming spring!!! I am putting up a new swing
set for my daughter so I know she will be enjoying it soon!

Best Regards,
Paul

if you took a moment to read SAC's comment above, the issue with multiple layers of fabric is in reference to incident angle. and unless your side-wall first reflection point panels are angled such that the ingress energy's incident angle is 0* (perpendicular to the panel), you haven't proved anything yet. your hand clap test does not take this into consideration, as i assume you hand-clapped directly in front of (perpendicular) the absorber.

[localhost127]

Originally Posted by Rick Sutton

Man, I know I should stay out of this but here goes.
My 40 plus years in the studio game leads me to say latestflavor has the best handle on this situation.
The thing that is starting to bother me in these acoustic threads is the overload of reliance on academic bludgeoning and just plain outright disrespect shown by several of our "learned colleagues" to argue their points.
In one thread the academics argue that their is no "effective" difference in a hard surface made out of different materials......you know, the old wood floor/glass floor type of debate. But in this thread our experts tell us that a little extra fabric (possibly a very light one, who knows?) is going to be a real problem when added to a DIY panel already covered in fabric. I, and others will argue that there is no "effective" difference in this situation.
I realize that most of the experts here are just trying to help but I sense one or more are just trying to exercise their academic chops and don't have a real handle on the application of all their knowledge.
Spare me the explanations. I've been to university too. Studied architectural acoustics in the dark ages. I'm sure it has changes and evolved....to a point. But I've heard the differences of adding additional fabric in this type of situation many times and they are not "effectively" a big deal. I've probably spent more hours in............never mind, I'll spare you all my gory details.
I'll leave you to your scientific analysis of this "o' so complex" situation. Just remember, we're not talking a symphony hall here. There is actually an effective difference, you know, between a symphony hall and a small space with some DIY panels.....yes, I know you know.......just sayin'.

Rod, my post just happens to be directly under yours, it is not specifically a response to yours. My rant stems more from a recent situation of interesting threads on acoustics unfortunately turning into useless information argue fests loaded with red-herrings from both "camps".

i disagree 100%

the 'academic bludgeoning',as you put it --- describes a solution or explains a question with pin point accuracy and clarity, with little chance for mis-interpretation. with general/simplistic (read: non-scientific) responses, it generally only leads me to ask more questions for follow-up clarification...as things weren't explains to their fullest in the original post.

if you want a herd-mentality of promoting lazy and non-scientific discussion, then i hope that takes place elsewhere and doesn't destroy the snr of this forum.

[pauloticks]

Originally Posted by localhost127

if you took a moment to read SAC's comment above, the issue with multiple layers of fabric is in reference to incident angle. and unless your side-wall first reflection point panels are angled such that the ingress energy's incident angle is 0* (perpendicular to the panel), you haven't proved anything yet. your hand clap test does not take this into consideration, as i assume you hand-clapped directly in front of (perpendicular) the absorber.

I have been nothing but thankful and kind to all the advice but I am getting tired of the lack of humility and general rudeness some of the responses seem
to possess. The hand clap test thing was a joke. Hence the word scientific in parentheses. Also I am glad to see that you are in the room with me watching where I am clapping. Do you really thing I am a moron? Yes let's clap right into a panel and see what happens. Seriously come on now. When you assume to know something it only does one thing, it makes an ass out of u and me. Thank you US Army for driving that into my head until my retirement hahahaha.

[localhost127]

Originally Posted by pauloticks

but I am getting tired of the lack of humility and general rudeness some of the responses seem
to possess. .

then you're more than free to pay a professional to come out and answer any of your questions.