ShinOBIWAN said:
I looked at this link.
At the top of his page he quotes Lord Kelvin:
"...when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science..."
So, I followed the wiki link provided on the Contact page to get a definition of heuristic:
"The OED defines heuristic as "serving to find out or discover". It is a set of rules or principles used to aid in the discovery process which in fact can be quite complex depending upon the process. The test is not whether they are common sense but whether they aid in the process of discovery. Some would suspect some common sense rules would not meet the test of heuristic.
A heuristic is a method to help to solve a problem, commonly informal. It is particularly used for a method that often rapidly leads to a solution that is usually reasonably close to the best possible answer. Heuristics are "rules of thumb", educated guesses, intuitive judgments or simply common sense."
OED is the Oxford English Dictionary, so I checked their site and found this definition of heuristic:
"enabling a person to discover or learn something for themselves." 😀
This is not intended as any slight on Mark K or his opinions. I just found it amusing.
Cheers,
Alex
Hi Alex,
Even the bedrock of science - 'calculus' - requires some methods which appear illogical at outset to untrained humans for fundamentally sound scientific proofs to be achieved.
If measurements do not reveal the cause of verifiable observations, then correct methods for investigation are not being applied.
I do look forwards to reading of some irrefutable baffle/port verification, because the pressure/contour aspect has not yet been fully investigated
Cheers ............ Graham.
Even the bedrock of science - 'calculus' - requires some methods which appear illogical at outset to untrained humans for fundamentally sound scientific proofs to be achieved.
If measurements do not reveal the cause of verifiable observations, then correct methods for investigation are not being applied.
I do look forwards to reading of some irrefutable baffle/port verification, because the pressure/contour aspect has not yet been fully investigated
Cheers ............ Graham.
Carlp said:
Hi,
How can you get it so wrong ? The "civility in presenting their
cases" is in fact as far as I can tell simply not listening and
ignoring anything that does not suit them and then indulging
in tedious conjecture that has little to do with anything.
You do not understand "confidence" has nothing to do with
it, defending the blantantly obvious is simply not necessary.
Speaker design is not rocket science, its only complicated
if you choose to ignore the fundamentals, and if you do this
you are, as has been repeatedly stated, not talking sense.
I'll also note BudP has now backtracked himself into a purely
subjective position, claiming EnABLing baffle appears to reduce /
eliminate "lobing" that he can hear for the untreated baffle case.
As ever the objective position is anything significantly audible
is also measurable. So theory aside, there is a mechanism to
indicate if baffle EnAbling does anything. I'm still waiting ........
🙂/sreten.
Graham Maynard said:
We agree on this, that may surprise you. However, the missing factor on baffles and ports was and is verifiable observations. Anecdotes are not verifiable observations, that would be measurements themselves or properly conducted audibility studies, something that can be and is duplicable by others.
Dave
So we're back to the only possible next step. A verifiable blind or double blind listening test - preferably for both driver AND baffle/port (since I don't get the sense the driver issue is fully resolved in all minds). Can I suggest listeners should be Budp, dlr, John K, Alex from Oz, Sreten, and soongsc. In the same room. Maybe the moderators could run the tests. A modest proposal. Maybe we could get a driver manufacturer to fly everyone to the same location.... 😉
Carl
Carl
Carlp said:
Hi Carl. I know you're saying this tongue-in-cheek, but actually it's not the only possible next step. Measurements actually are a possible next step, the logical next step if one does not accept the indications of current tests and theory as to impact, since no one has made any measurements on ports. However, if they were to show no significant change or none measurable, as certain ones of us here expect, then at that point we would still lack verifiable observations. One could then try a double-blind listening test, but the question I would pose would be, why?
Dave
dlr said:
I was too late to edit my previous post.
I just recalled that John K had said that he had enabled a port and had measured and listened to it. IIRC he said that he neither heard nor measured a difference. So the next step has been taken by one person at least.
If a port is not simultaneously passing frequencies higher than the one to which it is tuned, then maybe EnABL treatment close to the edge of its room pressurising opening might not be rendered audible.
A-B recording of the same piece of music close to one loudspeaker port with EnABL, and then with EnABL removed - nothing else being moved or changed - then synchronising playback and subtracting the two recorded signals in real time will reveal any difference.
I suggested subtractive methods months ago in the original thread, but such ideas were poo-hoo'd because 'better' methods were said to be available.
Cheers ......... Graham.
A-B recording of the same piece of music close to one loudspeaker port with EnABL, and then with EnABL removed - nothing else being moved or changed - then synchronising playback and subtracting the two recorded signals in real time will reveal any difference.
I suggested subtractive methods months ago in the original thread, but such ideas were poo-hoo'd because 'better' methods were said to be available.
Cheers ......... Graham.
This ranting about not measuring the right thing or that the measurements are not revealing what is happening is really sour grapes, IMO.
It’s not very difficult to know what to measure here. It is the sound radiated by the speaker, period! Measured it where ever you like, on axis, off axis, at you listening position, at 1 meter, what ever you like. If you do not believe that we can measure acoustic disturbances to greater accuracy that we can hear you should really rethink you position. 
If you think you need to use music then please go here: http://www.libinst.com/Audio DiffMaker.htm and download the software and do your own tests. The software is free!
If you don't believe that mics are sensitive enough in the first place, may I remind you that every piece of recorded music you listen to began with a mic converting acoustic waves to electrical signals.
It’s not very difficult to know what to measure here. It is the sound radiated by the speaker, period! Measured it where ever you like, on axis, off axis, at you listening position, at 1 meter, what ever you like. If you do not believe that we can measure acoustic disturbances to greater accuracy that we can hear you should really rethink you position. If you think you need to use music then please go here: http://www.libinst.com/Audio DiffMaker.htm and download the software and do your own tests. The software is free!
If you don't believe that mics are sensitive enough in the first place, may I remind you that every piece of recorded music you listen to began with a mic converting acoustic waves to electrical signals.
Graham Maynard said:
Don't you think that an MLS signal, which is basically non random noise, has a wider frequency spectrum than some arbitrary selection of music?
And not that it matters, but if you suggected subtractive methods in the original was it before or after I did? 🙂 I don't recall it being poo-hoo'd. I just recall it being ignored by proponents, as was typical.
Anyway, I have posted a link to free software that will allow such differnces to be made. The only problem I see is that the software can only allow sync to within a sample rate so if the samppling isn't initiated at exactly the same time the resulting differences could just be the result of an interasample shift. It would be necessary to look at the software to see how this is resolved. Since Bill Waslo developed the software I suspect it has been addressed.
Sounds like a good idea.🙂 It's been a few years since I've last visited the US. It seems reasonable for people whom claim to hear a difference to bring in the speakers and have others listen as well, just to get some feeling whether others think there is a difference or not, and whether it's considered an improvement. Whomever thinks there is an improvement can recommend how measurements can be made to appropriately show technically that there is an improvement.Carlp said:
In my own measurements and teaking process, I did notice that certain spectral decay patterns can produce the illusion that some specific instruments have more detail. Additionally, driver that has a longer decay time will seem louder than the one that sounds cleaner (which has a shorter decay time). Furthermore, the decay properies actually might create more audible difference in sound balance than just looking at the frequency response.
Hi John,
'Ranting' ?
'Sour Grapes' ?
Any chance of you stopping this attemptedly belittling behavior ?
I have see such attitudes as spoiling the original and this technical thread, whether intend as such or not.
And there is no need for your attempted lecturing of me either, because I have suggested obviating loudspeaker mass change induced effects by monitoring changes at a baffle edge or a port where re-distributed driver mass *cannot* be involved !!!
Can anyone look at measured differences (CSD etc.) in isolation, and know what the composite of those differences will do to the on-going music reproduction we hear ?
We need to isolate the changes we are hearing, and if we do obtain a 'difference' signal then we can also gain cues about what causes it; these cues then suggesting what/when/how to measure !
And if we cannot hear a difference then there is no point in devising any measurement procedure either. However; if we do hear EnABL induced changes at a baffle edge or a port, then 'distributed additional mass' cannot be stated as being the only reason for EnABL having an effect when applied to cones.
Thus, much could be learned from testing EnABL at a baffle edge or in a port with music drive, and whether anyone wants to use their favourite test methods thereafter is up to them. Until then there should not be any attempts by anyone to impose any specific methodolgy upon anyone else, which is why I merely present a case for my suggestion.
Cheers .......... Graham.
'Ranting' ?
'Sour Grapes' ?
Any chance of you stopping this attemptedly belittling behavior ?
I have see such attitudes as spoiling the original and this technical thread, whether intend as such or not.
And there is no need for your attempted lecturing of me either, because I have suggested obviating loudspeaker mass change induced effects by monitoring changes at a baffle edge or a port where re-distributed driver mass *cannot* be involved !!!
Can anyone look at measured differences (CSD etc.) in isolation, and know what the composite of those differences will do to the on-going music reproduction we hear ?
We need to isolate the changes we are hearing, and if we do obtain a 'difference' signal then we can also gain cues about what causes it; these cues then suggesting what/when/how to measure !
And if we cannot hear a difference then there is no point in devising any measurement procedure either. However; if we do hear EnABL induced changes at a baffle edge or a port, then 'distributed additional mass' cannot be stated as being the only reason for EnABL having an effect when applied to cones.
Thus, much could be learned from testing EnABL at a baffle edge or in a port with music drive, and whether anyone wants to use their favourite test methods thereafter is up to them. Until then there should not be any attempts by anyone to impose any specific methodolgy upon anyone else, which is why I merely present a case for my suggestion.
Cheers .......... Graham.
Graham Maynard said:
Hi,
I thought you were going to give it a rest ..... no such luck.
Whatever, test away for port / baffle EnABL with whatever method
you like. The only thing of note would be some repeatable significant
result. Which you could learn from if it occurs. You will learn nothing
pontificating on what would cause such a result and therefore its
consequences when no such result is expected.
You do not understand the meaning of objective.
The above is tedious ranting that is utterly pointless.
Spoiling a technical thread ? I'd suggest that is your department ....
🙂/sreten.
Graham Maynard said:
Sure sounds like ranting to me.
Go listen. Go measure. Go make the difference comparisons (I gave you a link to free software to do it). Define what you have done so that it can be independently verified. Do something constructive.
Hi John K,
I'd would so love to do something constructive, but I have long term injury which prevents me from doing so many things almost everyone else takes for granted.
For me everyday life is a toss up of what I can do - like talking, like washing, like doing things with my arms; for everything has a cost which then means I am finished with grinding in-head pains, tinnitus and I can't do anything else but sit quietly until the next day or two or....
In case you don't realise I am merely (and quite calmly) trying to prompt others to carry out further investigations, and there is nothing wrong with that !
So for the 3rd time - I cannot do any of this testing.
And Sreten,
Please do not make quotes of my words out of their posting context.
I am looking forwards to seeing irrefutable verification of EnABL effect at a port/baffle either way, not as you are making out with my words - as if I expect there to be a positive verification of EnABL effect ONLY.
The pressure/contour aspect has not been covered (if I am wrong here please correct me), but if there is no EnABL effect then there is no reason to consider such possibility any further.
Laser CT of pressure contours at a port exit might be interesting too - from a technical viewpoint; even though I don't like the sound of resonant augmentation, and so would be wary of using same.
Cheers ......... Graham.
I'd would so love to do something constructive, but I have long term injury which prevents me from doing so many things almost everyone else takes for granted.
For me everyday life is a toss up of what I can do - like talking, like washing, like doing things with my arms; for everything has a cost which then means I am finished with grinding in-head pains, tinnitus and I can't do anything else but sit quietly until the next day or two or....
In case you don't realise I am merely (and quite calmly) trying to prompt others to carry out further investigations, and there is nothing wrong with that !
So for the 3rd time - I cannot do any of this testing.
And Sreten,
Please do not make quotes of my words out of their posting context.
I am looking forwards to seeing irrefutable verification of EnABL effect at a port/baffle either way, not as you are making out with my words - as if I expect there to be a positive verification of EnABL effect ONLY.
The pressure/contour aspect has not been covered (if I am wrong here please correct me), but if there is no EnABL effect then there is no reason to consider such possibility any further.
Laser CT of pressure contours at a port exit might be interesting too - from a technical viewpoint; even though I don't like the sound of resonant augmentation, and so would be wary of using same.
Cheers ......... Graham.
Graham Maynard said:
Let's see, you say that you want measurements to show what's occurring, whether positive or negative. John has made a number of measurements that show that essentially nothing is going on. Each time, someone found fault. So John responded. Still nothing. You reject it. You claim to be neutral, yet deny the evidence when it's not positive and insist on some other measurement method due to your rejection of the essentially ubiquitous MLS. I don't think your words are being misconstrued one bit, you will accept only a positive.
Wouldn't we all be interested in this! So what? It's not necessary to measure the acoustic output of a port. All evidence to date points to an enabled baffle or port not showing anything out of the ordinary happening and face it, there is hard evidence on both. It's not going to happen anyway, so why even talk about it? It's better to focus on the realistic.
Dave
Graham Maynard said:
I sincerely hope that you make a full recovery. On the other hand, I don't intend to do any further measurements until I find something that prompts me to believe they are necessary. I think it should be stated that I don't just sit around and take a couple of measurements, post them and get pompous. I have spend more than a few hours doing research on this subject and have probably spend over $400 on advanced books and references on acoustic to bolster my basic understanding (just because I’m interested). I use such exchanges not only to partake in the discussion but also to as a means of finding interesting topics from which I can increase my knowledge. When I look into other factors that might influence propagation of acoustic waves what I find is that yes, there are things that move the results around but none of these would impact the effect (or lack there of) of enable patches. That’s on the analysis side. The measurements remain what they are and the theory tells me things aren’t going to change. So until I see a well documented measurement that shows something odd happening I see no reason to increase my efforts on the experimental side. I’m not opposed to changing my opinion on anything. I just don’t do it lightly.
Absolutely tongue-in-cheek, but also somewhat seriously. John K has fairly definitively demonstrated that given his technique and the forces he was trying to measure, nothing was happening (at least audibly). Others have suggested issues that perhaps John K hasn't addressed (I don't have enough understanding of the issues and physics to have an opinion here). There is debate over that, sure, but that's exactly why, at some level, the double blind testing seems to be the only thing left. Unless we can first put to bed the question of whether or not there is an audible difference, I don't hold out much hope for progress beyond where we are right now.
Re: John K's listening test, I don't seem to recall it being double blind (or even blind, though I might be mistaken), so I'd hardly call that the next step.
Finally, I agree about measuring ports, but at some level we haven't even yet determined that we agree for sure on what to measure (let's assume we did double blind testing and you and John K found an audible difference from EnABL'd ports and baffles - crazy I know - that would suggest John K missed the mark in his measurements), so I'm not sure I agree that measuring is a worthwhile next step before the objective listening tests.
(Frustrating how, statistically, the burden on those wishing to disprove is harder than the burden on those who wish to prove... Otherwise, we'd have put this to rest long ago.)
Carl
Carlp said:
I'm sorry Carl, those who continually suggest that something is not being measured somehow do not understand the capabilities of MLS measurements. No amount of explanation gets through. If MLS did not work, then manufacturers would not use it as their primary measurement systems. It's almost universal. Even those with true anechoic chambers use it in one way or another.
Of course it wasn't double blind, but then neither are those of any proponents. That's secondary, anyway, the "next step" was actual measurements that John produced, as requested remember. The clamor was for modding, measuring and listening. It didn't have to be double blind to be accepted if it was positive. No proponent has ever been skeptical of anything another proponent claimed. Never. It was all accepted and praised while at the same time if you didn't hear a difference, then the immediate response was to question how the application was made. We don't need to go back there again.
"At some level" is being stuck on denying the facts and the capabilities of the measurement systems. It's part of the denial. Ports can be measured easily. The acoustic response doesn't have some mystical property that eludes the current measurement systems. There's no other way to put it.
Actually, the burden is not on skeptics, it is on the proponents to prove the positive claimed. So far, the score is zero on that. The measurements provided, done to show reality, not positive or negative, has fallen only on the negative side for baffles and ports. As John said, the measurements are what they are, a mic doesn't care one way or the other about the source. All it does, very effectively, is measure the sound pressure changes. You can't even say dispassionately, since it's inanimate and simply responds according to the physics.
And as John so deftly pointed out, every recording anyone in the world listens to was first sensed by a mic that output a time-continuous analog voltage in reaction to the sound pressure variations at that single point in space. The end result is a time-continuous analog voltage supplied to the driver. It can be no better than the analog output from that first mic. That's if everything in between were perfect. But one thing is sure, the measurement mic can be the equivalent of that recording mic. It's kind of the analog (excuse the pun) to the computer case of garbage in, garbage out. What you hear can be no better than that first mic.
Dave
I don't know MLS so can't comment except to say that some still question the adequacy of John's measurements to put the issue to bed. Again, that's not my position specifically, but it's part of why I said the only thing that would put this to bed is double blind testing with both sides involved (the not-tongue-in-cheek part). That way, either side would have to accept the straight-face test. If skeptics heard a difference, maybe they'd be motivated to continue the discussion with an eye toward what's been missed, and if proponents couldn't hear a difference, then they'd have to accept the results John you and others have been trying to convince them of for some time now.
Carl