# Testing Loudspeaker Isolation Products



## Ethan Winer

I was inspired by Todd Anderson's test of the IsoAcoustics Aperta to do my own in-depth analysis of isolation including testing several devices. Enjoy:

Testing Loudspeaker Isolation Products

Enjoy!

--Ethan


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## robbo266317

Thanks for doing the tests Ethan, an endeavour beyond most of our reach since we don't have access to multiple products. :TT
Your highlighting the difference made by speaker placement, including ensuring that they are at the correct height, emphasizes the fact that people should be spending most of their effort optimising their layout before considering any other treatment.

-Bill


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## NBPk402

Thanks Ethan, I just got done reading it and it is very good info. :T:T


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## Tonto

Thanks Ethan, good info to pass along.


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## Talley

OK... how about this then. How do you measure sonics? You can't... or can you? Nobody has a calibrated file to go with their own ears so you must rely on your ears and your brain. If your brain can be fooled by tricks... then the product works.


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## NBPk402

Talley said:


> OK... how about this then. How do you measure sonics? You can't... or can you? Nobody has a calibrated file to go with their own ears so you must rely on your ears and your brain. If your brain can be fooled by tricks... then the product works.


Your brain can be tricked by your feeling good about your purchase...doesn't mean it actually worked, it just means you think it does.


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## robbo266317

I wonder if anyone has done a study on endorphin levels after buying something new. 
Whether it be a set of speaker, an album or anything else and how this affects your perceived listening pleasure.


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## NBPk402

robbo266317 said:


> I wonder if anyone has done a study on endorphin levels after buying something new.
> Whether it be a set of speaker, an album or anything else and how this affects your perceived listening pleasure.


Did you ever see the Dolby Labs article about amps... The guy setup an amp that didn't work (as I recall a tube amp), and then appeared to be switching between the 2 amps being tested, and most of the people picked the nice looking tube amp that didn't even work, when they were listening to the same amp all along. LOL


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## robbo266317

I didn't see that actual article. However, listener bias is a real problem. (You may have noticed that I rant Ad Nauseum about double blind tests, but they are rarely carried out. lddude: )

With the Isolation products this would be a relatively simple task as they could hide what was below the speaker by a black cloth curtain and let the listener evaluate cardboard boxes, expensive foam products, Gorilla Glue and even common house-bricks... Only after a double blind test with reproducible results would I be convinced that there was any benefit. (The Gorilla Glue may pose some post listening problems. :R )

I extend this argument to speaker "spikes"! 
The only real situation this _could_ be of benefit would be on plush carpet which may allow the speaker to move minutely back and forth, but wait I digress, wouldn't the foam blocks also allow the speakers some sort of horizontal movement as well. :scratchhead:


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## willis7469

Ethan, that was great! Thank you for doing what many of us want to. If I tried, I could possibly convince myself that iso products could be useful under speakers. Maybe... Before those tests. 
Something I found offensive actually was this:








Seriously...?
If all these super mega awesome products do all these magical things, wouldn't oem's endorse them? Or make their own? Oh wait, they already know...


Sent from my iPhone using Tapatalk


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## dgmartin

Thanks for the fun read confirming my skepticism! In the end whether it has an impact or not is all about the foundation stiffness vs the cabinet mass, driver mass and positions etc.


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## Talley

ellisr63 said:


> Your brain can be tricked by your feeling good about your purchase...doesn't mean it actually worked, it just means you think it does.


I get that. Doesn't answer my question. How do you measure sonics? For example... why do we not use aluminum speaker cable? Sure it's resistance is higher so you must use a larger diameter cable to get the same properties as the copper equivalent but equally spec'd aren't they the same? One minor issue being the aluminum shrink/expansion based on it's temperature BUT... wouldn't they both be the same because they measure the same?

How do you measure it's sonics? I've yet to see people come close to this which is why you have to rely on your easily fooled brain to do so. 

years ago I stumbled across beryllium copper and it's acoustical properties in this article: http://materion.com/~/media/Files/P...coustic Properties of Beryllium_Materion.pdf/ Unfortunately these measurements are in the Mhz frequencies 

It's implied that there is sonic measurement capabilites beyond resistance and such for cabling


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## Talley

ellisr63 said:


> Your brain can be tricked by your feeling good about your purchase...doesn't mean it actually worked, it just means you think it does.


And also... I was super excited about my emotiva xpa-7 purchase... very excited. but immediately the highs sounded cold.

My mind was excited but as soon as I turned it on I was let down. Explain that trickery?


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## AudiocRaver

Nice work and good feedback and questions.

It seems that one of the main problems with isolation & anchoring products is that they are so often used without thought or analysis as to what is to be accomplished in a given situation and the kind of product or material most likely to help accomplish what is needed. Mr Weiner's article points this out.

The two main classes of products we are talking about are isolation and anchoring products.

Isolation keeps vibrations from getting from where they are already to where you do not want them to end up.
Anchoring products do the opposite, they allow vibrations to be absorbed into a bigger mass to help eliminate them.
Different products work in different ways, and the user really has to look closely at what is going on in the product: absorption or transmission, at what frequencies, in what direction? Products exist which anchor in one plane while isolating in another, or which anchor at audio frequencies while isolating at subsonic frequencies, for instance.

A potential problem with testing - and I absolutely applaud the use of both lab testing and blind listening tests for verification - is that the use or lack of use of a given product may effect soundstage and imaging (SS&I) in ways that are audible yet might be difficult to pick out in typical acoustical lab tests. Note that I am not claiming them to be immeasurable, only difficult to measure, and perhaps calling for very specialized techniques.


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## dgmartin

Talley said:


> I get that. Doesn't answer my question. How do you measure sonics? For example... why do we not use aluminum speaker cable? Sure it's resistance is higher so you must use a larger diameter cable to get the same properties as the copper equivalent but equally spec'd aren't they the same? One minor issue being the aluminum shrink/expansion based on it's temperature BUT... wouldn't they both be the same because they measure the same?
> 
> How do you measure it's sonics? I've yet to see people come close to this which is why you have to rely on your easily fooled brain to do so.
> 
> years ago I stumbled across beryllium copper and it's acoustical properties in this article: http://materion.com/~/media/Files/P...coustic Properties of Beryllium_Materion.pdf/ Unfortunately these measurements are in the Mhz frequencies
> 
> It's implied that there is sonic measurement capabilites beyond resistance and such for cabling


The datasheet you referenced is about Beryllium and not beryllium- copper. It refers to Be's mechanical properties, from which vibration and acoustic properties behavior could be derived (for example as a tweeter dome material). This has nothing to do with its electrical properties as a speaker cable. The effect of adding a pure material (Be) into an alloy does not usually trends with the alloying material's properties.


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## Talley

dgmartin said:


> The datasheet you referenced is about Beryllium and not beryllium- copper. It refers to Be's mechanical properties, from which vibration and acoustic properties behavior could be derived (for example as a tweeter dome material). This has nothing to do with its electrical properties as a speaker cable. The effect of adding a pure material (Be) into an alloy does not usually trends with the alloying material's properties.


How do you measure sonics?


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## AudiocRaver

Talley said:


> How do you measure sonics?


I think the question will have to be more specific. What sonics? In what situation?


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## Talley

AudiocRaver said:


> Nice work and good feedback and questions.
> 
> It seems that one of the main problems with isolation & anchoring products is that they are so often used without thought or analysis as to what is to be accomplished in a given situation and the kind of product or material most likely to help accomplish what is needed. Mr Weiner's article points this out.
> 
> The two main classes of products we are talking about are isolation and anchoring products.
> 
> Isolation keeps vibrations from getting from where they are already to where you do not want them to end up.
> Anchoring products do the opposite, they allow vibrations to be absorbed into a bigger mass to help eliminate them.
> Different products work in different ways, and the user really has to look closely at what is going on in the product: absorption or transmission, at what frequencies, in what direction? Products exist which anchor in one plane while isolating in another, or which anchor at audio frequencies while isolating at subsonic frequencies, for instance.
> 
> A potential problem with testing - and I absolutely applaud the use of both lab testing and blind listening tests for verification - is that the use or lack of use of a given product may effect soundstage and imaging (SS&I) in ways that are audible yet might be difficult to pick out in typical acoustical lab tests. Note that I am not claiming them to be immeasurable, only difficult to measure, and perhaps calling for very specialized techniques.


I think me being a bit harder to explain my reasons and when I mention "how do you measure sonics".... SS&I is a form of sonics that to this point like you mentioned is one of the items that simply are difficult to measure if not impossible.

Thank you for another view and I agree. I applaud his efforts and comments but they should be taken into consideration that it's only one piece of a complete package. A guitar can be made from maple.... the same guitar can be made from pine. Which sounds better? How can you measure the affect of the sonics of wood?


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## Talley

AudiocRaver said:


> I think the question will have to be more specific. What sonics? In what situation?


See my post above. Materials have sonics = they resonate. SS&I is a kind of sonic imho. Phasing is a sonic that is measurable. sonic is just simply something you hear. But materials have sonic characteristics. two rooms.... one room entirely concrete... the other steel matching the specs of the concrete room. Would they sound the same? No... Different materials resonate and have different sonics.


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## AudiocRaver

Talley said:


> See my post above. Materials have sonics = they resonate. SS&I is a kind of sonic imho. Phasing is a sonic that is measurable. sonic is just simply something you hear. But materials have sonic characteristics. two rooms.... one room entirely concrete... the other steel matching the specs of the concrete room. Would they sound the same? No... Different materials resonate and have different sonics.


Gotcha. And, to use your example, "same specs" would give "same sonics" if those specs were all-inclusive of all possible sonic-related characteristics, but of course they never are. A given product's specs cover the characteristics that most people want to see most the time, and to go beyond that would demand an infinite amount of testing and an infinitely long spec sheet. Practicality wins, and, as you say, it is very possible for a set of specs to miss a measurement that would demonstrate an important sonic difference between two products or materials or situations. Yet we do our best - we endeavor to persevere!


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## Talley

AudiocRaver said:


> Gotcha. And, to use your example, "same specs" would give "same sonics" if those specs were all-inclusive of all possible sonic-related characteristics, but of course they never are. A given product's specs cover the characteristics that most people want to see most the time, and to go beyond that would demand an infinite amount of testing and an infinitely long spec sheet. Practicality wins, and, as you say, it is very possible for a set of specs to miss a measurement that would demonstrate an important sonic difference between two products or materials or situations. Yet we do our best - we endeavor to persevere!


Yes I agree.


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## ajinfla

Talley said:


> How do you measure sonics?


Exact same way it's recorded. Microphone.


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## robbo266317

I think the term "sonics" has been inserted purely to be a red herring.
The dictionary defines sonics as to be of, or pertaining to, sound, therefore is not a measurable entity.

We should be focused on real world differences that can be demonstrated either by via measurement or repeatable double blind listening tests.

So far, apart from the original posters extensive testing, I see no arguments supporting the validity of these products.


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## tonyvdb

I agree, if you don't hear a difference then there is no benefit to these products. In the end what you hear is what's important.


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## Ethan Winer

robbo266317 said:


> I think the term "sonics" has been inserted purely to be a red herring. The dictionary defines sonics as to be of, or pertaining to, sound, therefore is not a measurable entity.


Yes, exactly, well put. We can answer "how to measure" only if the question is more specific. I can assure Talley that everything that affects audio quality can be measured, and to levels below what any human can hear. For example, we can measure the difference between 0.002 and 0.003 percent distortion, but nobody can possibly distinguish that small a difference by ear, or even hear distortion that soft at all.

Talley, if you really care about this stuff and are willing to invest 50 minutes, my AES video explains a lot of this in great detail:






--Ethan


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## Todd Anderson

Very interesting results, Ethan. Great work. Thanks for taking the time to take all of these measurements!

I encourage all of you to hit a show and see if you can hear IsoAcoustic's stands in action... close your eyes and listen... see if you can hear a difference in height leveled speakers. You're ears will have to be the ultimate judge. Maybe you will...maybe you won't.... you'll have to be the judge.

Perhaps the stands are more about dialing height and directionality? If so, they serve a purpose...that being said, if you can achieve that through other methods, then that purpose would be negated. 

Very interesting stuff... let the debate continue!


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## ajinfla

Todd Anderson said:


> Perhaps the stands are more about dialing height and directionality?


Hi Todd,

Here are vertical measurements of the typical tweeter/woofer arrangement as found in the vast majority of speakers on the market









As you can see, even small elevation changes will result in very audible differences (ears are very sensitive in 1-3k region).
I'd be very surprised if someone didn't hear differences with these stands.
I don't discourage audiophiles from seeking isolation remedies, but they may not work quite as purported.

cheers,


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## Talley

Todd Anderson said:


> Very interesting results, Ethan. Great work. Thanks for taking the time to take all of these measurements!
> 
> I encourage all of you to hit a show and see if you can hear IsoAcoustic's stands in action... close your eyes and listen... see if you can hear a difference in height leveled speakers. You're ears will have to be the ultimate judge. Maybe you will...maybe you won't.... you'll have to be the judge.
> 
> Perhaps the stands are more about dialing height and directionality? If so, they serve a purpose...that being said, if you can achieve that through other methods, then that purpose would be negated.
> 
> Very interesting stuff... let the debate continue!


I find the difference could be more due to exact alignment more than anything maybe?....


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## robbo266317

That's quite an interesting graph AJ.



Talley said:


> I find the difference could be more due to exact alignment more than anything maybe?....


Again, looking at the plot AJ posted it seems to indicate that the alignment is a major player and well worth closer scrutiny. 
I might have to try different seating heights since I have floor standing speakers and can only raise them...


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## Talley

My uncle says no matter what you do the speakers have to be 100% matching. Down to the .01° on plumb/level and down to the .05" of height matching.... this is about 1/128 of an inch. He claims once you get to that degree of accuracy the sound really comes together on it's own.


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## willis7469

Talley said:


> My uncle says no matter what you do the speakers have to be 100% matching. Down to the .01° on plumb/level and down to the .05" of height matching.... this is about 1/128 of an inch. He claims once you get to that degree of accuracy the sound really comes together on it's own.



I believe there is something to this. BUT, what happens when you have 2 separate listening sessions? Say, one in your pj's, and one in your work clothes with the 4" thick talley family wallet in your pocket? Lol!
The point is, if you sit in the LP 50 times, your not gonna get your head in the exact same spot 50 times. My suspicion is that by having true alignment, the LP's window is more cohesive over a slightly larger area so the effects of not sitting within 1/128th of an inch are lessened. Or the audio equivalent of focusing your tamron lense for clarity, or manually setting convergence on an RPTV. Once the (audio) image comes into focus, it can be experienced over a wider range(within a couple inches) and remain clear. Does that make any sense?


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## Medi0gre

You would need millwright instruments for those tolerances


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## NBPk402

willis7469 said:


> I believe there is something to this. BUT, what happens when you have 2 separate listening sessions? Say, one in your pj's, and one in your work clothes with the 4" thick talley family wallet in your pocket? Lol!
> The point is, if you sit in the LP 50 times, your not gonna get your head in the exact same spot 50 times. My suspicion is that by having true alignment, the LP's window is more cohesive over a slightly larger area so the effects of not sitting within 1/128th of an inch are lessened. Or the audio equivalent of focusing your tamron lense for clarity, or manually setting convergence on an RPTV. Once the (audio) image comes into focus, it can be experienced over a wider range(within a couple inches) and remain clear. Does that make any sense?
> 
> 
> Sent from my iPhone using Tapatalk



What we did last time was tune the room to a point behind the MLP so the MLP essentially becomes wider...you can also tune to a point in front of the MLP. Try it and see what you think.


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## willis7469

My best so far is a point about 4' behind the LP. 


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## Talley

Medi0gre said:


> You would need millwright instruments for those tolerances


His level was $600. Yes it's a millwright level.

Yes you are correct. Once I get my Maple blocks he is going to send me his level so I can do my speakers. I'm just using the maple block to help achieve perfect alignment.


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## Talley

willis7469 said:


> I believe there is something to this. BUT, what happens when you have 2 separate listening sessions? Say, one in your pj's, and one in your work clothes with the 4" thick talley family wallet in your pocket? Lol!
> The point is, if you sit in the LP 50 times, your not gonna get your head in the exact same spot 50 times. My suspicion is that by having true alignment, the LP's window is more cohesive over a slightly larger area so the effects of not sitting within 1/128th of an inch are lessened. Or the audio equivalent of focusing your tamron lense for clarity, or manually setting convergence on an RPTV. Once the (audio) image comes into focus, it can be experienced over a wider range(within a couple inches) and remain clear. Does that make any sense?
> 
> 
> Sent from my iPhone using Tapatalk


I agree. by having both speakers perfect your aligning the speakers to the room and thus should be creating a larger sweet spot.

This is where audio tricks and your brain come into play. We don't hear all the weird FR changes that goes on by moving the mic 1" an having dips drastically change. WE simply don't hear the change.

So IMHO it's more about perfect alignment for room interaction than you.


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## Medi0gre

I think you would be better off with a theodolite.


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## dgmartin

willis7469 said:


> My best so far is a point about 4' behind the LP.


 I've come to a similar setup, which I now call LP 

BTW, I might be oversimplifying things, but the first thing that strikes me looking at the vertical dispersion plot posted by AJ is the angle scale. If we convert that into delta height at the LP, then 1deg corresponds roughly 2in height (1deg*pi/180*60in ~ 1in per 5ft). This seems reasonably achievable/repeatable to me.

I think the speaker foundation stiffness/damping subject could be sorted out by sticking an accelerometer on the front baffle and sending the conditioned signal into the same spectrum analyzer that measures FR... that way we know if the treatment is helping a bad stand, adding distortion or playing with our minds.


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## willis7469

dgmartin said:


> I've come to a similar setup, which I now call LP


Yes indeed. 


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## AudiocRaver

Allow em to throw a little gasoline onto the fire!

Talley's comments have come under fire. I will defend his views, at least partly, with the following observations.

When I have achieved extremely precise alignment in my own setups, the result has been that an IMPACT is achieved that covers a fairly wide sweet spot. The effect completely defies the argument that you do not sit in the same point of space every time you listen. I do not yet understand the physics or the math that supports this, but I am still working on figuring it out. I have achieved this in 3 different rooms.


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## willis7469

Thanks Wayne. That's kinda what I was trying to say. 


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## Todd Anderson

AudiocRaver said:


> Allow em to throw a little gasoline onto the fire!
> 
> Talley's comments have come under fire. I will defend his views, at least partly, with the following observations.
> 
> When I have achieved extremely precise alignment in my own setups, the result has been that an IMPACT is achieved that covers a fairly wide sweet spot. The effect completely defies the argument that you do not sit in the same point of space every time you listen. I do not yet understand the physics or the math that supports this, but I am still working on figuring it out. I have achieved this in 3 different rooms.


Wayne, we sat together and listened to IsoAcoustics...both heard the "mashed potatoes" vs "tight imaging".... while that was happening, did you suspect there was some kind of trickery going on? Curious.


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## lcaillo

I don't think it is trickery, and really don't have a precise understanding of it, but I have also experienced what Wayne describes. In the dozens of speakers that we tweaked positioning on (which Wayne has a great skill at fine tuning and I have a skill at getting in the ballpark, so we make a great team) some of the most impressive results were noted from the 2nd row in the "Sonnie Sessions." My belief based on these experiences is that the fine tuning of direct vs. reflected sound plays a big part, but you have to start with a speaker that facilitates it in the setting of the room. The experiences that Wayne has shared with many speakers and positioning in various settings, along with the success reported with Dirac, IMO, supports this notion, vague as it is.


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## Savjac

Talley said:


> My uncle says no matter what you do the speakers have to be 100% matching. Down to the .01° on plumb/level and down to the .05" of height matching.... this is about 1/128 of an inch. He claims once you get to that degree of accuracy the sound really comes together on it's own.


I am sorry Talley but this tolerance, in reality will easily be discounted the moment that we sit down to listen unless we also include a vice for our heads to keep us aligned accordingly.

I am not saying we should not strive for perfection, I just believe that as listeners, we cannot truly achieve uncles claim. Even in real life, we will move our heads about and still the music will be fine. 

On Saturday I had a very long listening session at a friends house wherein we listened to equipment costing well over $300,000. Even though one speaker was slightly out of align, things sounded so fantastic I wept often. Yes setup is very important but having the proper set up close to perfect, will still allow an awesome presentation.


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## AudiocRaver

Todd Anderson said:


> Wayne, we sat together and listened to IsoAcoustics...both heard the "mashed potatoes" vs "tight imaging".... while that was happening, did you suspect there was some kind of trickery going on? Curious.


Todd ,

I remember it very clearly. It was only later when I got to thinking about it that I started asking questions. What exactly was going on there? Was there isolation, absorption, both, at what frequencies, in what plane, in what direction? We definitely heard a difference, but then one has to ask exactly what was being accomplished under what circumstances and why? There is no doubt that a situation can be set up, contrived, or selected that a person could run into, where that might be a valid product. Under another set of circumstances, a completely different product may be called for with the very same speakers.

I am NOT trying to invalidate what we heard. But the tendency for marketing those kinds of products is to take a specific demonstration like that and generalize it to a cure-all type of claim. Or a universal need claim. In one studio set up, those isolators might be the perfect solution. In another, they might be a complete waste of time, not due to product characteristics but due to that needs in that situation being different.


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## AudiocRaver

Talley, Savjac, you are both right. There are certain kinds of circumstances that can create really magical audio results. Some of them involve a kind of precision and tolerances that Talley talks about Some of them involve other conditions as Savjac has witnessed. Be at peace, brothers.


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## Savjac

AudiocRaver said:


> Talley, Savjac, you are both right. There are certain kinds of circumstances that can create really magical audio results. Some of them involve a kind of precision and tolerances that Talley talks about Some of them involve other conditions as Savjac has witnessed. Be at peace, brothers.


Thanks Wayne, at peace I am. 
The experiments that many fellows on the forum have done prove to me that it is possible to get the equipment set up perfectly so as to allow one to delve into the music quite handily and we can all learn from these suggestions. I am not quite as good at set up as you and Talleys uncle, close to be sure but not down to the atomic level and yet I really think I am getting a good approximation of what is on the record. I kind of want the readers to know that all is not lost if the tolerances noted by Mr T's uncle are not met.

I hope that makes sense.


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## Ethan Winer

Savjac said:


> this tolerance, in reality will easily be discounted the moment that we sit down to listen unless we also include a vice for our heads to keep us aligned accordingly.


Yes, I'm certain that a tiny change in listener position is the real reason people insist they hear an improvement after:


isolating speakers on special stands
raising speaker wires off the floor
replacing an AC power cord
all other "power" products
too many other "tweaks" to list​

Moving even one inch can change the response enough to notice, and moving only four inches makes a dramatic change:

A common-sense explanation of audiophile beliefs

--Ethan


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## witchdoctor

Excellent job, love the attention to detail and the graphs. You may want to listen to the Mapleshade Bedrock speaker stands for the future.


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## Talley

Savjac said:


> I am sorry Talley but this tolerance, in reality will easily be discounted the moment that we sit down to listen unless we also include a vice for our heads to keep us aligned accordingly.
> 
> I am not saying we should not strive for perfection, I just believe that as listeners, we cannot truly achieve uncles claim. Even in real life, we will move our heads about and still the music will be fine.
> 
> On Saturday I had a very long listening session at a friends house wherein we listened to equipment costing well over $300,000. Even though one speaker was slightly out of align, things sounded so fantastic I wept often. Yes setup is very important but having the proper set up close to perfect, will still allow an awesome presentation.


has nothing to do with where you sit. it's speaker to speaker alignment. the source.


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## AudiocRaver

Savjac said:


> I am sorry Talley but this tolerance, in reality will easily be discounted the moment that we sit down to listen unless we also include a vice for our heads to keep us aligned accordingly.


I must disagree somewhat with the "head in a vice" inference. The following plots show, for the left and right speaker in my system, the effect of moving my head 3 inches left or 3 inches right, of the head-centered position for each ear.









If your setup is decent, you will notice little difference by moving your head left/right a few inches. If you cannot do so without hearing a significant difference, your setup needs serious attention, you will have no repeatability, life in general will probably seem full of frustration and pretty pointless - _joking!_

Even the benefits of precision setup (2 to 3 mm) can be enjoyed with normal head movement at the LP. It is the relative time alignment of lower-mid frequencies with wavelengths in the 1 foot to 5 foot range (1 kHz to 200 Hz) that are benefiting, the main effect being on soundstage and imaging. Part of that time-aligned benefit enters the body through the chest and skull at those frequencies, also contributing to a sense of impact with certain sounds, and small head movement does not negate it.

Please NEVER use the "head in a vice" reference again - _joking again!_

EDIT:
HAVING SAID THAT... It is, unfortunately, probably true that, for many setups, head position/movement might very well account for differences that people think they hear.


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## Savjac

Ethan Winer said:


> Yes, I'm certain that a tiny change in listener position is the real reason people insist they hear an improvement after:
> 
> 
> isolating speakers on special stands
> raising speaker wires off the floor
> replacing an AC power cord
> all other "power" products
> too many other "tweaks" to list​
> 
> Moving even one inch can change the response enough to notice, and moving only four inches makes a dramatic change:
> 
> 
> 
> --Ethan


Absolutely Ethan, moving but an inch can change perspective and on occasion it can change the sound of music. I am not so sure about raising the speaker wires up off the floor although, I am using some super sized legos and the sound has become a bit plastic, not sure why but I will look into this issue. :devil:

I do think isolating a turntable is a good idea especially in a room that has a wood floor as there can be terrible vibrations to be sure. Maybe even a CD player but I see no purpose to isolating the amps and preamps. At least that is my belief.


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## AudiocRaver

Ethan Winer said:


> Yes, I'm certain that a tiny change in listener position is the real reason people insist they hear an improvement after:
> 
> 
> isolating speakers on special stands
> raising speaker wires off the floor
> replacing an AC power cord
> all other "power" products
> too many other "tweaks" to list​
> 
> Moving even one inch can change the response enough to notice, and moving only four inches makes a dramatic change:
> 
> A common-sense explanation of audiophile beliefs
> 
> --Ethan


Ethan, not arguing that it does not occur, and - sadly - probably a LOT, the situation you describe - with that much audible change from a little head movement - sounds like a poor setup to me, not to be tolerated. My opinion.


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## Savjac

AudiocRaver said:


> I must disagree somewhat with the "head in a vice" inference. The following plots show, for the left and right speaker in my system, the effect of moving my head 3 inches left or 3 inches right, of the head-centered position for each ear.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> If your setup is decent, you will notice little difference by moving your head left/right a few inches. If you cannot do so without hearing a significant difference, your setup needs serious attention, you will have no repeatability, life in general will probably seem full of frustration and pretty pointless - _joking!_
> 
> Even the benefits of precision setup (2 to 3 mm) can be enjoyed with normal head movement at the LP. It is the relative time alignment of lower-mid frequencies with wavelengths in the 1 foot to 5 foot range (1 kHz to 200 Hz) that are benefiting, the main effect being on soundstage and imaging. Part of that time-aligned benefit enters the body through the chest and skull at those frequencies, also contributing to a sense of impact with certain sounds, and small head movement does not negate it.
> 
> Please NEVER use the "head in a vice" reference again - _joking again!_
> 
> EDIT:
> HAVING SAID THAT... It is, unfortunately, probably true that, for many setups, head position/movement might very well account for differences that people think they hear.


Well you are right good sir, my life is full of frustration and accordingly seems entirely pointless. :innocent:

At this point I do not have your fine speakers, which do have some latitude in head movement and provides you with a life full of joy, happiness and sunshine. I have horns and I do feel that when listening to the little guys in the cabinets, moving my head does allow for some issues in way if slings and arrows with no hope for fortune beyond being allowed to work for a pittance on this mortal coil, whatever that is. :coocoo:
I do hope to obtain another set of ESL's in the near future before my life unravels completely. :clap:

Spoken with tongue firmly placed in my cheek.


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## AudiocRaver

Savjac said:


> Well you are right good sir, my life is full of frustration and accordingly seems entirely pointless. :innocent:
> 
> At this point I do not have your fine speakers, which do have some latitude in head movement and provides you with a life full of joy, happiness and sunshine. I have horns and I do feel that when listening to the little guys in the cabinets, moving my head does allow for some issues in way if slings and arrows with no hope for fortune beyond being allowed to work for a pittance on this mortal coil, whatever that is. :coocoo:
> I do hope to obtain another set of ESL's in the near future before my life unravels completely. :clap:
> 
> Spoken with tongue firmly placed in my cheek.


I am relieved to hear there is still hope... Hold on, brother!!!


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## Savjac

AudiocRaver said:


> I am relieved to hear there is still hope... Hold on, brother!!!


Hope, I have not lost hope, that is what keeps most of us going with or against the odds. The Jack system is a wonder to behold, albeit that may be hard to believe, great dynamics, wonderful imaging that may be a bit short on depth but very good tonality that does allow the differences in gear and recordings, to make themselves known.
This is a difficult hobby but quite rewarding more often than not. :laugh2:


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## Ethan Winer

AudiocRaver said:


> The following plots show, for the left and right speaker in my system, the effect of moving my head 3 inches left or 3 inches right, of the head-centered position for each ear.


The problem with your graph is that the traces are third-octave averaged, which hides all the detail. :surprise:

If you remove the averaging you'll probably see differences much more like those in the article I linked earlier. Here it is again for your convenience:

A common-sense explanation of audiophile beliefs

Both the source (loudspeakers) and the receivers (ears or microphones) are highly position sensitive. If you move either you'll get large changes. The smaller the room, the more change you get.

--Ethan


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## Ethan Winer

Savjac said:


> I do think isolating a turntable is a good idea especially in a room that has a wood floor as there can be terrible vibrations to be sure. Maybe even a CD player but I see no purpose to isolating the amps and preamps. At least that is my belief.


Yes, for turntables, but that's a special case because they're mechanical devices that rumble and thump when jostled, and feed back at high volumes. But CD players are immune because the audio data passes through a playback buffer (computer memory). So unless you jostle a CD play severely so it skips, there won't be subtle changes in quality.

There's no reason to have beliefs about this stuff! All you need is an honest friend and a cloth blindfold to test this for yourself!

--Ethan


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## Ethan Winer

AudiocRaver said:


> Ethan, not arguing that it does not occur, and - sadly - probably a LOT, the situation you describe - with that much audible change from a little head movement - sounds like a poor setup to me, not to be tolerated. My opinion.


Yes and No. As mentioned in my "Beliefs" article, adding acoustic treatment does a lot to minimize the variation in response versus position. But even in an anechoic chamber the response will vary with placement due to differing arrivals times. Any mono content in a recording comes from both speakers, so being even an inch closer to one speaker will skew the response. And as you move slightly left and right that skewed response will change to a different skewed response.

It's amazing stereo, and even recording in general, works as well as it does! One reason it works is because each ear receives a different response, so we perceive more of an average. Another reason is we're used to hearing the sound change as we walk around our house and at the supermarket etc, so we don't notice it so much. I imagine a blind person notices the changing sound quality much more.

--Ethan


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## Savjac

Ethan
I have no argument with what is being presented here and I am learning a lot on this forum. Thank You

I have been at this music through audio equipment for a good long time now, 40 years or so and have never been able to hear the experience of proper placement of traps, diffusers etc. Partially because I had little exposure to the positives of proper room set up until recently when I started going back to axpona a couple years back. Second problem is of course the cost of knowing what to buy and where to put it. I can imagine many folks buying this or that with no knowledge of what to do with them.

Personally, like many, I just do not have the money to have an expert come in, size up the room, perform tests and supply the goods. Wow that can be expensive. So maybe one day when the economy turns in the right direction, we will all have a gazilion dollars to invest, until then....um....headphones. :laugh2:


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## Nodrog

ajinfla said:


> Exact same way it's recorded. Microphone.


Microphones can measure SPL. I have yet to see a microphone or measurement system, that can listen to music they way an ear and a brain can listen to music. For instance, when listening to music you can focus your attention on the drums or the guitar and sort of block out everything else. A microphone can't do that. Maybe this is why we can hear subtle differences in equipment. We focus on a little change in the timbre of a cymbal or a certain resonance in a vocal. And since everyone's brain and ear is different it is hard to get a consensus on these small changes.


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## Ethan Winer

Savjac said:


> have never been able to hear the experience of proper placement of traps, diffusers etc.


Well, if you ever pass through Connecticut you're welcome to stop in for a demo. It's tough to demo acoustic treatment in a video, but this comes pretty close:

Hearing is Believing

--Ethan


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## AudiocRaver

Ethan Winer said:


> The problem with your graph is that the traces are third-octave averaged, which hides all the detail.
> 
> If you remove the averaging you'll probably see differences much more like those in the article I linked earlier. Here it is again for your convenience:
> 
> 
> 
> Both the source (loudspeakers) and the receivers (ears or microphones) are highly position sensitive. If you move either you'll get large changes. The smaller the room, the more change you get.
> 
> --Ethan





Ethan Winer said:


> Yes and No. As mentioned in my "Beliefs" article, adding acoustic treatment does a lot to minimize the variation in response versus position. But even in an anechoic chamber the response will vary with placement due to differing arrivals times. Any mono content in a recording comes from both speakers, so being even an inch closer to one speaker will skew the response. And as you move slightly left and right that skewed response will change to a different skewed response.
> 
> It's amazing stereo, and even recording in general, works as well as it does! One reason it works is because each ear receives a different response, so we perceive more of an average. Another reason is we're used to hearing the sound change as we walk around our house and at the supermarket etc, so we don't notice it so much. I imagine a blind person notices the changing sound quality much more.
> 
> --Ethan




Indeed. Here is the 12th-octave version of the same plots.









My claim is not that moving the head should result in NO change in sound, that is simply not going to happen, as you have pointed out. But I will argue - respectfully - that with a reasonably well-executed listening setup, a small amount of head movement need not result in LARGE or even SIGNIFICANT changes in sound quality. The 12th octave graphs for my LP show some variation, of course, by shifting the head 3 inches left or right of center, but my assessment from the graphs and from experience is that those variations are small enough to be unnoticeable in a regular listening session. Here are a few qualifiers:

If asked if there is ANY difference noted by moving the head left or right, then the answer would be yes. The biggest change would be the slight shift of the center image and soundstage placement with the head shift. That change is unavoidable with most speaker types.
The frequency response changes shown in the above graph would border on being inaudible to the average listener. A more experienced ear might hear those differences, but would probably dismiss them as not being significant.
In my situation, there is a high chair back. Moving the head a few inches forward or backward does indeed result in easily audible changes in frequency response due to the reflections and cancellations from the chair back. The best solution is a low chair back, around shoulder level.
Up/down head movement is generally not a problem for seated humans.
As you state, the psychoacoustic brain puts up with a lot and helps us ignore a lot of variation unless we "tune in" and listen closely for it. The experienced listener can do this at will.

I know I am splitting hairs a bit. Your original point was that head position makes a difference that could account for some perceived cable/equipment differences, and I agree. The "head in a vice" assertions always prickle my interest because of the suggestion that either:

big variations are there anyway and we don't notice them. My assertion: with proper care and attention, and within the bounds of certain qualifiers, those variations need not be big at all, in fact can be close to inaudible, or
a super-narrow sweet spot is a pain to deal with, better to give up the benefits of precision placement than have to deal with a resulting narrow sweet spot. My assertion: precision placement to achieve certain sonic qualities DOES NOT necessarily produce a tiny sweet spot.

note: I had to remove a smilie from Ethan's quoted post because it kept showing up about 1 foot in diameter.


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## Savjac

Ethan Winer said:


> Well, if you ever pass through Connecticut you're welcome to stop in for a demo. It's tough to demo acoustic treatment in a video, but this comes pretty close:
> 
> Hearing is Believing
> 
> --Ethan


I believe you, been listening to you for years but only really experienced it at the show recently in the room pictured below, or maybe I should say the room next to the room below using the same equipment. I forgot their name but the properly set up room was a dream.

Keep rockin on the bass.


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## Ethan Winer

AudiocRaver said:


> Indeed. Here is the 12th-octave version of the same plots.


If you want to see the true responses, turn off _all_ averaging. :grin2:



> But I will argue - respectfully - that with a reasonably well-executed listening setup, a small amount of head movement need not result in LARGE or even SIGNIFICANT changes in sound quality.


Sure, and as I already pointed out, having acoustic treatment is the best way to minimize response differences versus position. Just having a larger room also helps.

--Ethan


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## AudiocRaver

Ethan Winer said:


> If you want to see the true responses, turn off _all_ averaging. :grin2


:

Why would I want to do that? Are you suggesting that the human ear can discriminate those kinds of variations?:frown:

Sixth or twelfth octave averaging are generally considered to represent the limits of ability to discriminate FR variations. I am a believer that the ear can be trained to hear in more detail with practice, and that a trained listener can hear more detail by "tuning in" to those details at will, within limits. I am doubtful that there is any benefit to looking at unsmoothed response for purposes of this discussion. I invite some justification for looking at unsmoothed response in the context of this discussion.


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## ajinfla

Nodrog said:


> Microphones can measure SPL.


Microphones captured the music/sound you listen to. That's why they can measure every aspect.


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## ajinfla

Savjac said:


> I forgot their name but the properly set up room was a dream.


Resolution Acoustics, my friend and fellow Tampa audio club guy Bart.

cheers


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## Savjac

ajinfla said:


> Resolution Acoustics, my friend and fellow Tampa audio club guy Bart.
> 
> cheers


Thank You AJ, I was very surprised at how well they did. I wonder if the vendor for this fine system would consider their products 
I think I need a long term listen to these puppies :innocent:


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## ajinfla

Savjac said:


> Thank You AJ, I was very surprised at how well they did. I wonder if the vendor for this fine system would consider their products
> I think I need a long term listen to these puppies


Hah. Actually I am working on a "tour" version pair. I'll put you on the top of list.:smile:
Beware, those are anti-"treatment" speakers. They are meant specifically to be used _without_ any form of so called treatments, to deliberately use the reflections, typical room mode issues, etc. as found in domestic listening spaces.
I visited the RA room as well (though in fairness, I get the hear those setups right here and more $OTA systems all year). I thought on some material, the treated room sounded better, on others, the untreated. So I asked several SAS (local club) members who were in attendance, what they thought. Ditto. Actually, one guy preferred the untreated room 100%. Classical music aficionado.:smile:
Preference. Both _sight_ and sound.

cheers,


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## Savjac

ajinfla said:


> Hah. Actually I am working on a "tour" version pair. I'll put you on the top of list.:smile:
> Beware, those are anti-"treatment" speakers. They are meant specifically to be used _without_ any form of so called treatments, to deliberately use the reflections, typical room mode issues, etc. as found in domestic listening spaces.
> I visited the RA room as well (though in fairness, I get the hear those setups right here and more $OTA systems all year). I thought on some material, the treated room sounded better, on others, the untreated. So I asked several SAS (local club) members who were in attendance, what they thought. Ditto. Actually, one guy preferred the untreated room 100%. Classical music aficionado.:smile:
> Preference. Both _sight_ and sound.
> 
> cheers,


Thank You, I would like that, however, I have no credentials that would benefit your good self and as such I am not sure anyone would listen to me. I did stop in twice, once I got to speak shortly with you but a demo was in progress and the second time another demo. Oh well next time. 

I have learned a good lesson here. Music and speakers will act differently when presented with varying types of room treatments, AND, one can make speakers that tend to be immune to room issues. That in and of itself speaks well of your designs. 
I am sorry for leading this thread astray and maybe we should start another one. :whistling:


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## Nodrog

ajinfla said:


> Microphones captured the music/sound you listen to. That's why they can measure every aspect.


It is true microphones work similarly to ears but there has yet to be developed a program to analyze the electrical signal from a microphone the way the brain can analyze the signal from the ear.


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## Ethan Winer

AudiocRaver said:


> Why would I want to do that? Are you suggesting that the human ear can discriminate those kinds of variations?


Yes, we can hear very narrow response changes. The key is whether frequencies in the music align with the frequencies in the response. This article proves the point using music and very narrow EQ that align in frequency:

Audibility of Narrow-Band EQ

Now, it's true that acoustic nulls are also positional, so a deep null at one ear may not be present in the other ear only a few inches away. In that case our brain averages the responses and we still hear the frequency because it's missing in only one ear. But not all nulls occupy a small physical area, and smoothing absolutely can hide content that is both real and audible.



> I am a believer that the ear can be trained to hear in more detail with practice, and that a trained listener can hear more detail by "tuning in" to those details at will, within limits.


Absolutely! But that's a different issue.

--Ethan


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## AudiocRaver

Ethan,

Thank you for the info. Very interesting.

If I may summarize our discussion so far, I believe you made the assertion that frequency response can vary significantly over a fairly small mic movement distance, and followed up with information showing that even narrow bandwidth response variations can be audible, and made the comment that it is somewhat of a marvel that we hear anything in stereo with any kind of precision. All good points, and I have no disagreement with any of them.

My point was simply that, in a reasonably well controlled environment, including the speaker setup, the variations across a few inches of head movement need not be objectionable, and indeed may be easy to ignore, or tune out, altogether under normal listening conditions. Although, as you pointed out, they are audible if you go looking for them.

I appreciate a good discussion, I think our little interchange has run its course, our remaining differences being in the realm of absolutes vs shades of grey.Thank you for your input.


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## Ethan Winer

^^^ I agree with all that. And I agree with your earlier premise that in a "good room" positional changes are less noticeable and less damaging than in a bad room. The best way to minimize these changes is with broadband absorption. Pity more people aren't aware of the importance of acoustics.

--Ethan


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## AudiocRaver

Ethan Winer said:


> The best way to minimize these changes is with broadband absorption. Pity more people aren't aware of the importance of acoustics.
> 
> --Ethan


Absolutely! Thanks, Ethan.


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## Todd Anderson

Interesting conversation on this topic. I like it.

Most certainly, there's something to be said for what is measured...and the scientific side of me says that it should trump all. I'm a big fan of science. But, the human mind (and its relationship with our own senses) is often a determining factor that dictates our own realities and, as far as I know, what can't be measured is exact human perception. In most (if not all) cases, science can give us a good estimated guess of what a person's perception might be, but truly measuring perception is impossible... especially when it comes to things that are easily quantified. Take "time," for instance. Humans have been able to measure time to dizzyingly precise levels -- levels so minute that they nearly defy comprehension. The atomic clock is able to measure time to less than a nano-second of error every day....yet the human mind ultimately dictates how each person perceives the shortness or length of periods of time. 

When it comes to audio, if a simple placebo effect causes a change in perception, then that perception then ultimately becomes reality...does it not? Placebo is amazingly powerful in how we _experience_ the world. I remember reading a study of two surgeries (one sham and one actual) where the placebo surgery had the same perceived outcome as the real one...but does that change the ultimate outcome? Not if change occurred. 

I'm really curious about the role in measurement of sound ultimately dictating exactly how stereo imaging (and all of the little qualities we love to talk about) _should_ be perceived, I have no doubt - zero - that speaker placement and the room are huge factors. But, if the true qualities of imaging that we experience were easily quantifiable and relayed through graphs... I wonder why the speaker industry hasn't tapped into this to demonstrate the exact soundstage/imaging characteristics of one pair of speakers vs another? Is imaging - the exact kind of imaging that a spectrum of people should repeatably _perceive_ - truly measurable?


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## willis7469

Todd, that was fun, and well thought out. I've often wondered if there was a way to measure those same things. In my mind, there exists a special camera that can measure, and render onscreen the effects of toe, alignment, panning etc, in real time. Much like how a thermal imaging camera works, or an infrared camera. Those are probably crude examples, but that's the best I got. (And it's stuck in my head lol). I, like you, have two schools of thought. My inner engineer says, black and white, while my inner starchild wants to believe so many claims made by crafty marketing rhetoric. Perception is reality. It's a phrase I use often. For me , it might depend on my mood, how I listen. Sometimes I want vocals, sometimes guitars, or drums, so I may focus on those things more at that time. This can be from the same songs, just at different times. Mostly, I rely on science, and measurements because they don't waver, based on human inconsistency. It also reminds me that my reality of perception isn't crazy! 


Sent from my iPhone using Tapatalk


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## ajinfla

Nodrog said:


> It is true microphones work similarly to ears but there has yet to be developed a program to analyze the electrical signal from a microphone the way the brain can analyze the signal from the ear.


Right. The microphone measures the soundfield, the human analyzes. There is nothing in the soundfield a microphone cannot capture. Either to get it onto your media, or afterwards.


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## ajinfla

Todd Anderson said:


> I have no doubt - zero - that *speaker placement and the room are huge factors*. But, if the true qualities of imaging that we experience were easily quantifiable and relayed through graphs... I wonder why the speaker industry hasn't tapped into this to demonstrate the exact soundstage/imaging characteristics of one pair of speakers vs another?


Hi Todd, didn't you just answer your own question?:smile: Spatial rendering depends on a host of factors, including the host.
Exactly what relevance would manufacturer provided spatial data provide? Impedance does not change with room, neither does the onset (free field frequency) response. Hence, those are relevant data. "Imaging" is not "a" thing. It's a bunch of things...that can each be measured (the soundfield aspect). 



Todd Anderson said:


> Is imaging - the exact kind of imaging that a spectrum of people should repeatably _perceive_ - truly measurable?


Yes...but only for that very specific circumstance and possibly, person.
It is helpful to understand what stereophonic is. Start with Alan Blumlein. He was an engineer, not a magician.:smile:

cheers


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## Ethan Winer

Todd Anderson said:


> Is imaging - the exact kind of imaging that a spectrum of people should repeatably _perceive_ - truly measurable?


I believe it is, but that's not what my loudspeaker isolation test was about. The _only_ thing I aimed to address is whether these things do anything at all. If they do, then consumers can listen and decide if the improvement is worth the asking price. But if they do nothing, then the entire product category can be dismissed as worthless and we can look for other, better, ways to improve the sound of our systems. I believe I succeeded in this regard. >

The issue of placebos, and why people believe they hear a change (almost always for the better) after replacing one competent AC power cord with another, is very different. It's just as interesting! But it's not the same as establishing that, for example:

* Some "power" products might (or might not) protect your audio equipment, but they do not improve sound quality even a little.

* Raising your speaker wires up on little elevators doesn't change the sound quality at all.

* Jitter from a typical DAC is so soft that it's not physically possible to have any effect on the sound at all.

There are _many_ more examples of things that make no difference, or if they do the difference is too small to hear, yet some people swear they heard an improvement. A lot of my efforts have gone into explaining this too. But again, it's not the same as establishing what is audible in the first place.

If you want to discuss how imaging might be measured, maybe that's worth a separate thread.

--Ethan


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## AudiocRaver

I think A.J. has hit the nail on the head here.

There is nothing about the sound in a room that cannot be measured by a microphone, amplitude, phase, impulse response, timing, etc.

But the creation of stereo imaging and soundstage takes place in the psychoacoustical brain and involves some complex processing. It all starts from those instinctive protection mechanisms that let us hear the direction a noise is coming from so we can tell where the lion or tiger is lurking in the bushes, getting ready to attack. We have come a long way from that beginning, now using it for entertainment.

The set of factors with a given room and speaker set that creates soundstage and imaging can be somewhat different from what occurs in another room. We can look at a number of measurements and possibly see why the SS&I are good, but there is no one graph or picture that shows SS&I quality all by itself.

Placebo: If the effect is stable, then it is reality. Placebo tends to not be stable. And what happens if it is stable for one person but not the same for another? It is no accident that our listening panels include a number of listeners with varying backgrounds and experience. Many times I have missed a listening quality that someone else pointed out, and when I listened for it, sure enough, there it was.

I really wish folks would quit saying "I am not a scientist" or "I am not an engineer" "...so I just trust my ears." Anyone who is seeking truth can be his own skeptic: "Am I really hearing a difference, or am I fooling myself? I want to be sure."


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## ajinfla

AudiocRaver said:


> "I am not a scientist" or "I am not an engineer"


Me neither, but I play one on TV

cheers


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## robbo266317

AudiocRaver said:


> But the creation of stereo imaging and soundstage takes place in the psychoacoustical brain and involves some complex processing. It all starts from those instinctive protection mechanisms that let us hear the direction a noise is coming from so we can tell where the lion or tiger is lurking in the bushes, getting ready to attack. We have come a long way from that beginning, now using it for entertainment.
> 
> I really wish folks would quit saying "I am not a scientist" or "I am not an engineer" "...so I just trust my ears." Anyone who is seeking truth can be his own skeptic: "Am I really hearing a difference, or am I fooling myself? I want to be sure."


I studied Electrical Engineering at University but I am not a scientist or an engineer. 

The creation of the stereo image, including height information, is started by the external ear. Have you wondered why it has all those curves and folds rather than being just a flat sound collector? 
The answer is that it performs an analogue "Fast Fourier Transform" on the incoming sound which gives the brain cues as to the location of sounds in 3 dimensions. I.E. up, down, left, right, forward and behind.

Then, as AudioCraver said, the psychoacoustical part of the brain gets involved with it's own complex processing.

As to the fact that ears are all slightly different, well.....

Cheers, Bill. 
I.T. Consultant


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