G'day dlr,
Firstly, I note that the baffle diffraction testing you did on your website was performed with the microphone at a distance of 1 metre from the speaker.
john k's test was done with the microphone only 9 inches from the dustcap.
In Post #257 john k states very clearly:
Secondly, I do not recall any claim that EnABL on a baffle eliminates diffraction.
Cheers,
Alex
Alex from Oz said:
That's immaterial to the analysis. The diffraction signature changes with location from the source because it is a time-delay phenomenon, but its effect is seen at all angles and all distances. Try out some free software such as The Edge or the Baffle Diffracion Simulator. See for yourself what happens to diffraction at any number of locations from the source that you care to try. It will change, but it will always be there.
John chose his mic position specifically to remove the diffraction signature from the analysis because his desire was to conduct a more basic test and isolate it to that of the wave passing over the applications. As he pointed out, if the wave is unaltered, the diffraction is unaltered. It's inescapable.
See above.
Bud can use whatever wording he cares to in describing the removal of baffle influences, but the only one in play is diffraction. A Rose is a Rose by any other name. Diffraction is diffraction regardless of descriptive words. Bud's claims can be nothing but diffraction if there is such change. Yet we know that diffraction cannot be controlled by the recommended enabl application since the acoustic wave that creates the diffraction in the first place is not altered by enabl as claimed. If the wave is not altered when it passes over an application, enabl or other, it will inevitably reach the baffle edge. Diffraction will occur unchanged from before the application.
Eliminate the possibility of alteration in the diffraction signature and the only thing left is placebo. That is also inescapable. It may (and will) be denied, but that does not change the reality.
Dave
John, I agree, and I wasn't challenging that. All I said was both sides should be reasonably self-critical and be aware of when they might be rejecting the other side simply b/c they don't like it or have some preconceived notions. I currently hear certain proponents of both "sides" failing to be objective in that way.
Au contraire. Remember, I'm talking about a disconnect between testing that rejects the sonic effects and the actual effects that some claim to hear. That disconnect exists, evidence is everywhere in this thread. Yes you're rejecting an opinion, but I don't think you can reject the fact that some people hear something that doesn't jibe with the conclusions presented here (I'm not saying the disconnect isn't due to placebo effect, I'm just saying it exists and that I'm not ready to accept placebo as the only explanation).
That said, it seems to me if you reject even the disconnect, then I don't know why you (or anyone, really) bother with this thread. For those of you, the answer is placebo and the problem is resolved. If you accept the disconnect, then it suggests digging further. In short, as some have stated quite obviously, the jury has delivered it's verdict, and for them, there's nothing more in this thread except to challenge personalities. I'd rather those folks just leave the thread unless they're willing to patiently respond to posts with rational responses. Otherwise, let's get on with theories and testing.
Put another way, it sounds like you reject the observations unless there is a theory that can support them, where as I, trained as a biologist, accept observation as a concept to be explored and only rejected when an explanation can't be found or a better explanation or observation is found.
Carl
This is the only page I can remember. Unless there is an easier way for the original poster to find specific posts...Daygloworange said:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=100399&perpage=25&pagenumber=12
Really hate getting into the broken record mode. How did we ever go through life without the net when we wanted data?
If you list all my posts throughout that old thread, you can find that I started out questioning the patterns until I found my own way (patent pending) of accomplishing results.
Just wish others could come up with more exciting results rather than just criticize people without addressing the guts and basis of thier findings. Engineers were not like that, at least the ones I've worked with, while I was in the US. But maybe the big attackers here are just hobbyists.
Thank you Carl for writing;-
>> I currently hear certain proponents of both "sides" failing to be objective in that way. <<
I have been accused (the two John's and DLR) in general of not liking their results (amongst other derogatory comments observed by others), which alone is offensive because I have repeatedly stated that I *do* appreciate their findings - for what they are.
However I do not like their 'stuck record' claims that their tests fully examine what is happening, and the way in which have failed to respond to (ignored) other test suggestions. They still sound as if on a soap box denying need to investigate further based upon their *opinion* of their technical findings, instead of brainstorming to cover all aspects, which has still yet to be done.
(Happy birthday John K. Sincerely.)
It is not for my want of trying that I have failed to get exponents to develop different tests, especially as tuned (wave pressurised) port testing with and without EnABL will look at air related effects alone; ie. no unproven arguments that all effects are due to additional cone mass ALONE !
Thank you Bud for clarifying what is necessary to keep technical minds focussed in this technical thread. The request to remove it suggests to me a wish to deny rather than to respond via further technical thinking or investigation.
Cheers ......... Graham.
>> I currently hear certain proponents of both "sides" failing to be objective in that way. <<
I have been accused (the two John's and DLR) in general of not liking their results (amongst other derogatory comments observed by others), which alone is offensive because I have repeatedly stated that I *do* appreciate their findings - for what they are.
However I do not like their 'stuck record' claims that their tests fully examine what is happening, and the way in which have failed to respond to (ignored) other test suggestions. They still sound as if on a soap box denying need to investigate further based upon their *opinion* of their technical findings, instead of brainstorming to cover all aspects, which has still yet to be done.
(Happy birthday John K. Sincerely.)
It is not for my want of trying that I have failed to get exponents to develop different tests, especially as tuned (wave pressurised) port testing with and without EnABL will look at air related effects alone; ie. no unproven arguments that all effects are due to additional cone mass ALONE !
Thank you Bud for clarifying what is necessary to keep technical minds focussed in this technical thread. The request to remove it suggests to me a wish to deny rather than to respond via further technical thinking or investigation.
Cheers ......... Graham.
sreten said:Hi,
Its one thing spouting BS and quite another spouting BS about the
original BS, which the proponents of EnABLing are rather good at :
In case you missed it :
quote:
(4.) Application of the complete process will effectively eliminate transient standing wave induced edge reflections on incident surfaces, commonly referred to as edge diffraction (fig.#s 10 & 11).
With even the original Author in denial it is a very sad state of affairs.
/sreten.
Thanks for that reminder. I had forgotten that it was there. That does help to set the record straight.
Much of the problem is that when measurements and analysis don't support the desired outcome, it is suggested that other measurements must be made. There is no acceptance unless it supports the preconceived notion of what must be. A prime example is the point made in various wordings intended to minimize the impact, such as it's only good for one particular driver (false) or that something is appreciated "for what they are". Both are nothing more than rejection and/or minimization, implying that the tests/analysis were insufficient when in fact the they fully address the specific issues. At some point, logic must enter into the picture.
No matter what is presented, the demand for "other tests" will not stop unless it is supportive of their position. So far, that count is zero.
I found it interesting to check the dictionary meaning of theory.
Theory
What we would find is, in part, numbers 1 and 2:
1. a coherent group of general propositions used as principles of explanation for a class of phenomena: Einstein's theory of relativity.
Up to this point, we have the theory of diffraction (not ours, BTW) from a body of texts and research papers which are well established, that to date has been supported be every measurement and analysis presented.
In addition, the extension of the measured baffle effects to drivers also supports the well-researched theory of drivers and added mass (again, not ours), with just one example of many possible being the measurements posted from the paper on ambient air pressure variation. To date, not a single piece of objective data supports anything other than the added mass principle.
2. a proposed explanation whose status is still conjectural, in contrast to well-established propositions that are regarded as reporting matters of actual fact.
To date the proponents fall exclusively into this category, at least those who would continue to question the objective results reported. They have nothing but proposed explanations, some of which have been subsequently proven wrong. Even more, when there is objective data that contradicts, new proposed explanations arise, as questions, of course, because there is nothing being presented by the proponents except questions and anecdotes. There is no hard data on which one may reach reasonably question the veracity of the hard data actually presented, yet the questions continue.
At this point, consider what the logical conclusion would be, then contrast that with what the various members of the thread have to say.
One last interesting quote from the linked page:
"A hypothesis is a conjecture put forth as a possible explanation of phenomena or relations, which serves as a basis of argument or experimentation to reach the truth: This idea is only a hypothesis."
We have a basis of argument and experimentation to reach the truth. The problem is, the truth to which the objective measurements and analysis point are rejected somewhat irrationally because it contradicts the desires of the proponents.
Dave
Maybe some, but not all. I accept what's been posted for data and (probably) explanation. But I remain open to the possibility that something really is going on that's either pretty extensive in terms of effect or very unexpected at the least. And I DON'T except the explanation of placebo effect by anyone who hasn't listened. Period.
Carl
Carlp said:
Reject what you will. I am open to other possibilities, but there has to be a basis in fact. So far, there has been nothing but new conjecture and questions and even denial by the author of having made the claim of control of diffraction.
The only two possibilities of merit to date are diffraction and placebo. We have been reminded that there was a specifical claim that diffraction would be effectively eliminated. If there are two and only two reasonable explanations for some situation and one of the two is ruled out (diffraction effects), what remains? Either accept that which remains (placebo) or make up some new cause. I will not accept the latter unless there is some evidence that there can be or is some new cause, rather than more conjecture and questions.
Dave
Sreten and Dave,
Bud clarified that the baffle edge pattern is comprised of blocks - not dots.
The EnABL pattern on a cone is dots placed at regions of coincidentally high alternating pressure/velocity energisation at/beside a discontinuity - centre cap or edge.
Please explain how your conclusions from the baffle test results (no local pressure gradient at the dots, and diffraction for the edge ridge) apply to dots on a cone/port.
Also please explain what pre-conceived notion you suggest I must have which leads to me not supporting any desired outcome. What outcome ? Do we have one ?
Too many questions remain unanswered !
Cheers ........... Graham.
Bud clarified that the baffle edge pattern is comprised of blocks - not dots.
The EnABL pattern on a cone is dots placed at regions of coincidentally high alternating pressure/velocity energisation at/beside a discontinuity - centre cap or edge.
Please explain how your conclusions from the baffle test results (no local pressure gradient at the dots, and diffraction for the edge ridge) apply to dots on a cone/port.
Also please explain what pre-conceived notion you suggest I must have which leads to me not supporting any desired outcome. What outcome ? Do we have one ?
Too many questions remain unanswered !
Cheers ........... Graham.
Graham Maynard said:
That clarification is immaterial to the discussion. Take that up with John K if you want since he performed the tests.
John K has already done so with regard to the mechanism of the induced changes in a driver. He touched on ports as well. Re-read his posts.
Just to clarify, placebo effect has not been applied to drivers.
Dave
An externally hosted image should be here but it was not working when we last tested it.
The above figure is a representation of the energy scattered by an enable patch realtive to the incident energy as a function of frequency. Note that this the total energy radiated in all directions, not just towards a listener or mic position. Pacth height is 0.0035".
Ha Dave,
You accuse, but do not answer technical questions !
Hi John,
Re your graph.
Air-side surface effects become dimensionally modified and tuned behind the radiating aperture of a driver cone opening. Those at the centre become peaked due to concentric focussing. This we know from specific sized/shaped drivers exhibiting characteristic output peaks.
Maybe some other lines could be drawn upon your graph relating to dimensional resonance and focussing effects due to driver shape/diameter for EnABL dots at the centre of a cone.
Maybe this would lead to driver specific peaks arising where presently there is a straight line and where our hearing is more sensitive ?
Cheers............. Graham.
You accuse, but do not answer technical questions !
Hi John,
Re your graph.
Air-side surface effects become dimensionally modified and tuned behind the radiating aperture of a driver cone opening. Those at the centre become peaked due to concentric focussing. This we know from specific sized/shaped drivers exhibiting characteristic output peaks.
Maybe some other lines could be drawn upon your graph relating to dimensional resonance and focussing effects due to driver shape/diameter for EnABL dots at the centre of a cone.
Maybe this would lead to driver specific peaks arising where presently there is a straight line and where our hearing is more sensitive ?
Cheers............. Graham.
Graham Maynard said:
Since you seem to have difficulty remembering and there is no need for me to redundantly describe what John has done so effectively, re-read this post of his:
John's post on extension to drivers (and other points)
So that the relevant point is not overlooked, here's a short quote from the above:
"What I have done is to demonstrate that a typical enable treatment, as would be applied to a driver, does not alter the propagation of an acoustic wave over a stationary surface. This is important because it can be argued mathematically that if it doesn't alter the propagation over a stationary surface it will also not alter the propagation over a vibrating surface."
I accept the logical extension. Of course, you may continue to deny, that is your prerogative and apparently your choice. It would carry some weight if there were some basis in fact for the denial. So far, none has been shown at any level.
Dave
Graham Maynard said:
Hi,
I have no intention of answering any random questions addressed
to me or correcting the vast quantities of meaningless tecnobabble
that surrounds EnABL.
They say intelligence is being able to ask the right questions,
dealing with the wrong or meaningless questions gets you
nowhere, in terms of understanding or education.
Furthermore I also have no intention of going over what has already
been categorically stated to be the case in its own correct terms, in
terms of some irrelevant interpretation.
I do not accept the a priori assumptions of significant effect.
My position is EnABL patterns, (not the cone coating),
are hyped up BS until shown to be otherwise.
I also suggest you try and read at least enough to have some
semblance of knowing the scope of what you are talking about.
Dots vs Blocks ? Where did that come from ?
Making it up as you go along methinks ......
I'm also not interested in what you think is :
"brainstorming to cover all aspects, which has still yet to be done."
Sounds like an invitation to advanced BS'ing.
/sreten.dlr said:
Hi,
Whilst the "debate" over EnABLing solid surfaces can rumble on
pointlessly ad infinitum, unless some some objective measurements
turn up, I'm not holding my breath, what about something useful ?
Specifically FEA modelling of drivers according to the above.
If FEA can usefully model driver cones before they are built it
should (if it supports the local granularity required) be able to
predict in some fashion - at least order of magnitude - effects
of adding the EnABL patterns, and one would expect a useful
ability to predict the effects of coatings.
No-one is denying treatment of cones changes them - but how much ?
If an effect can be modelled then you are at least on your way to
some objective optimisation (or rejection) of the patterns, and
presumably some alternative treatments could be compared.
Biggest problem I have with the EnABL patterns is they show no
design. The original description of "how they worked" suggested
the patterns, but this description has been shown to be wrong.
Given no evidence or any sensible reasoning that the patterns
are optimum there is no sensible reason to presume they are.
The attached file illustrates the FEA principle. I note that it could
be used in reverse, i.e. if you have a driver response and some
of the data required, some parameters could be inferred by
matching the output to your known response.
Or TBH simply model a theoretical driver with a reasonably
real looking frequency response and then play around with it.
(Much higher granularity than shown would be needed)
/sreten.http://www.interdomain.net.au/~bodzio/Cone_Break_Up.zip
ucla88 said:
Unless we're arguing that EnABL magically improves the low end where the driver acts like a piston.
Maybe someone's made that claim and I missed it. And MLS is quite real, so let's keep it real...
Hi,
Just being pedantic :
I have (and he has) no idea of what he is talking about.
/sreten.
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