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Why don't all speaker manufacturers design for flat on-axis and smooth off-axis?

Krunok

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In Olive's paper, the slope of the Early Reflections Directivity Index and the Sound Power Directivity Index are noted as ERDI_SL and SPDI_SL, respectively. Both anticorrelate with preference with r = ~-0.2. I don't think much can be concluded from this. Also, this number is from data from the smaller test (Test One), not the large-scale study. One way to try to get to the bottom of the influence of ERDI/SPDI might be to do some analysis on the raw data.

In that case you are right, nothing much can be concludedd from that.
 

Thomas_A

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My guess is that manufacturers like Harman don't really perform measurements in different rooms. They aim to manufacture a speaker that would sound better in any room than speaker with worse measurements in anechoic environment.

That is my guess also. And since they use a standardised listening room for tests that probably would translate to an average living room, you cannot translate those results to a different room. If they have an aim to manufacture a speaker, my guess they use the data to make a speaker ideal for the average living room. My preference is to have a wider dispersion for a smaller-than-average room, especially if you are forced to sit very close to the back wall.
 

Krunok

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That is my guess also. And since they use a standardised listening room for tests that probably would translate to an average living room, you cannot translate those results to a different room.

Well, if speaker A and speaker B are so similar in spinorama parameters except for the slope in Di graphs from what @edechamps quoted we cannot possibly tell not only how you would evaluate them in your room but we cannot tell how you would evaluate them in any room (Harman testing room included) as that parameter is not correlated.
 

Thomas_A

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Well, if speaker A and speaker B are so similar in spinorama parameters except for the slope in Di graphs from what @edechamps quoted we cannot possibly tell not only how you would evaluate them in your room but we cannot tell how you would evaluate them in any room (Harman testing room included) as that parameter is not correlated.

I would say that you can only conclude that from the experiments made in the Harman testing room. That room is considerably larger than my room, and has no wall directly behind the listener seat.
 

Krunok

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I would say that you can only conclude that from the experiments made in the Harman testing room. That room is considerably larger than my room, and has no wall directly behind the listener seat.

I think the point of our discussion is not if some speaker would sound the same in your room as it sounds in Harman room - point is if speaker A that sounds better in Harman's room than speaker B would also sound better in your than speaker B.
 

Thomas_A

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I think the point of our discussion is not if some speaker would sound the same in your room as it sounds in Harman room - point is if speaker A that sounds better in Harman's room than speaker B would also sound better in your than speaker B.

With respect to linear on axis and smooth off axis it would sound better in my room as in Harmans room. This can be clearly understood since peaks/dips in the response both on and off axis are audible. Other than that there is no data from the Harman experiment to say if the slope of DI matters in small rooms. I just can say that the back wall close to the listener causes problems that is not easy to deal with but can be "minimised" by "filling in the gaps" with reflections from other boundaries in the room.
 

Krunok

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With respect to linear on axis and smooth off axis it would sound better in my room as in Harmans room. This can be clearly understood since peaks/dips in the response both on and off axis are audible. Other than that there is no data from the Harman experiment to say if the slope of DI matters in small rooms. I just can say that the back wall close to the listener causes problems that is not easy to deal with but can be "minimised" by "filling in the gaps" with reflections from other boundaries in the room.

Most in-room problems with speakers that measure well can be solved with room EQ. Putting something absortpive on that wall may also help.
 

Thomas_A

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Most in-room problems with speakers that measure well can be solved with room EQ. Putting something absortpive on that wall may also help.

I have used parametric EQ in the past (Behringer) for the two subs and plan to buy a HT amp with some option to adjust one or two bass peaks. For the treatment of walls I just use panels on the loudspeaker side and normal furniture, rug on the floor, paintings/decorations on the walls etc. Have tried side and listener wall several times but I threw these panels out quite quickly. Absorption directly behind the head causes some strange studio/dead or airplane feeling in my ears/head.
 

Juhazi

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Dr. Earl Geddes has given a second opinion and many many speaker enthusiasts agree. High DI gives better imaging by inducing less early reflections in small rooms (typical home listening environment).
http://www.gedlee.com/Papers/papers.aspx
http://www.gedlee.com/downloads/AT/Chapter_8.pdf

Other research
https://www.researchgate.net/public..._sound_quality_-_a_review_of_existing_studies
http://iosr.surrey.ac.uk/projects/directivity/
--> "A series of experiments using such a system with a novel elicitation and analysis technique reveals that: changes in loudspeaker directivity interact with changes in room surface absorption to mostly affect perceived width, loudness and reverberence; a narrowing in on-axis directivity is associated with a perceived reduction in width, brightness, closeness and spaciousness; the perceptual changes caused by variations in loudspeaker directivity and in room surface absorption occur in parallel, along one dimension; the magnitude of effects caused by variations in loudspeaker directivity is reduced with the increased presence of reflections; and classical music is an effective signal to highlight the perceptual differences between different loudspeaker directivities. The influence of listener position can be significant, but the degree of its effect is dependent on the range of positions evaluated, and the magnitude of boundary separation has less effect than directivity on the perception of reproduced sound. Finally, loudspeaker directivity does influence listener preference."
http://www.davidgriesinger.com/laaes2.pdf

http://linkwitzlab.com/The_Magic/The_Magic.htm
-->" In a reverberant room, where the listener not only hears the direct sound but also the reflected sound, i.e. the off-axis radiated sound, the ear-brain perceptual apparatus must be allowed to withdraw attention from the room and speakers and focus attention upon the direct sound to create a convincing illusion of the reproduced acoustic event. For this to happen misleading perceptual cues must be eliminated. The speakers must be placed so that reflections are delayed relative to the direct sound. The speakers must be free from spurious resonant radiation and their off-axis radiation must follow their on-axis frequency response for the reverberant sound to be neutral. The polar radiation pattern must be essentially either omni-directional, cardioid or dipolar, aiming for constant directivity. The speakers must be acoustically small, yet capable of realistic volume levels at low non-linear distortion. "

Discussion at other forums and sites
http://techtalk.parts-express.com/f...r-directivity-in-home-sized-rooms-earl-geddes
http://www.acousticfrontiers.com/20...kers-open-up-your-acoustic-treatment-options/
https://www.diyaudio.com/forums/multi-way/195124-ideal-directivity-pattern-stereo-speakers.html

To sum it up I say- high DI increases the direct/reflected sound power ratio in small rooms, it affects stereo imaging, clarity, spaciousness, timbral accuracy etc. perceptual attributes of hearing. Changes in directivity across the passband should be smooth, but it is obvious that there is no
universal ideal value of DI/freq or shape of spinorama.

Differrent rooms, different type of music and just "taste" of the listener have big effect on what directivity profile a listener prefers. Sound monitoring at studio sets a different goal which should be standardized, and there are guidelines for that. I happen to have three different listening rooms with three different kind of speakers to satisfy my desire for variation (di-, omni- and coaxial monopole)!
 
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digitalfrost

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Anybody who has not heard a good full-range speaker should try it. They have their downsides, but they were my start in DIY as they are cheap to make. The imaging is exceptional. Tang Band W3-871S comes to mind. It's a 3" chassis that can produce bass down to 50hz in the right enclosure. Of course, it doesn't go very loud. As you go up in size with full-range drivers, the sweet spot becomes very small. I remember horns with Beyma 8AG/N - an 8" fullrange - you basically had to have your head in a vise to remain in the sweet spot.

I dabbled with multi chassis speakers for a while, but I eventually found my home with KEF coaxial chassis. That said, I listen at very close distances usually, so I'm probably more sensitive than normal people. I think a good multi chassis speaker with controlled directivity can be very good, especially as crossover slopes becomes steeper or actively controlled with 24db LR or steeper.

So from own experience, I agree that higher DI is likely better.
 

Cosmik

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...
http://linkwitzlab.com/The_Magic/The_Magic.htm
-->" In a reverberant room, where the listener not only hears the direct sound but also the reflected sound, i.e. the off-axis radiated sound, the ear-brain perceptual apparatus must be allowed to withdraw attention from the room and speakers and focus attention upon the direct sound to create a convincing illusion of the reproduced acoustic event. For this to happen misleading perceptual cues must be eliminated. The speakers must be placed so that reflections are delayed relative to the direct sound. The speakers must be free from spurious resonant radiation and their off-axis radiation must follow their on-axis frequency response for the reverberant sound to be neutral. The polar radiation pattern must be essentially either omni-directional, cardioid or dipolar, aiming for constant directivity. The speakers must be acoustically small, yet capable of realistic volume levels at low non-linear distortion. "
The Linkwitz quote is yet another 'we hear through the room' statement. SL defines the neutral speaker and tells us that all we need to do is place it in a room and the ears & brain will do the rest. There is no suggestion that you need to measure its in-room response or impose any sort of target curve. This neutrality is what the Grimm, Kii and D&D people are aiming for implicitly.
 

svart-hvitt

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I think most of the problem with getting through with your message - which I partly agree upon, I think - is that you do not have an engineering/technical/scientific background and mindset, and that is revealed in this statement; the idea that science is something that can be agreed upon and solved as a political compromise.

In science there is one correct answer, and then all the other answers are simply wrong. And the decision on what is correct and what is wrong is based in scientifical technical evidence, and the decision process in itself is based on logic. So there is no middle way.

This way, we occasionally find answers that do not fit into our perception of how the world is supposed to be, but we accept the answers as truth because there is a backtrack of evidence and a logical decision behind.

I know no norwegian forum where you can have a meaningful discussion about Toole's work or anything similar.

FREQUENCY RESPONSE: EN ENTICING MARKETING STORY

! Warning! - - - long post!!! - - -

@Kvalsvoll, it’s not as if I am unfamiliar with the history or philosophy (for example epistemology) of science. You wrote:

«In science there is one correct answer, and then all the other answers are simply wrong. And the decision on what is correct and what is wrong is based in scientifical technical evidence, and the decision process in itself is based on logic. So there is no middle way».

What you describe here is actucally a binary system, with only two outcomes, one or zero, absolutely correct or absolutely wrong. Limited numbers of states can be described by pure mathematics. If all properties can be fully predicted by pure logic alone, we don’t need experiments to confirm our beliefs or wisdom. I believe @Cosmik is in the camp of pure mathematics, a camp which I would call “philosophical” not “scientific”.

Reproduction of sound is HIGHLY complex as it is a result of factors such as:

(1) The sound field coming from loudspeaker can be formulated by complex functions, and
(2) Our perception of sound follows a series of complex cognitive processes.

In other words, the prediction of reproduced sound – which means combining (1) and (2) above – is so complex one could liken it to opening a can of worms. However, smart people dealing with complexity have had a recipe for ages: Vox populi. In 1907, Francis Galton, who according to Wikipedia was a “an English Victorian era statistician, polymath, sociologist, psychologist, anthropologist, eugenicist, tropical explorer, geographer, inventor, meteorologist, proto-geneticist, and psychometrician”, had to revisit his estimations of the wisdom of the public. At the annual show of the West of England Fat Stock and Poultry Exhibition people had a chance to guess the weight of an ox. The most correct estimates won prizes. Surprised by the outcome of the public’s guesses, Galton wrote:

“It appears, then, that in this particular instance, that the vox populi is correct to within 1 percent of the real value (…) The result is, I think, more creditable to the trustworthiness of a democratic judgment than might have been expected”.
Source: http://galton.org/essays/1900-1911/galton-1907-vox-populi.pdf

The polling method was later refined by none other than the Project RAND to find fast solutions to complex problems utilizing the power of group judgment, by gathering a group of experts (see: https://en.m.wikipedia.org/wiki/Delphi_method). Needless to say, RAND was populated by the best science people, with the aim of winning the (cold) war. In other words, they didn’t search for a solution as if the outcome were a binary, philosophical one, but a forecasting solution that was adaptive, robust and able to deal with complexity.

So it is in this tradition, the democratic vox populi line of thinking, that audio researchers use polls too instead of mathematics alone to find solutions to the sound reproduction problem, given the fact that predicting both (1) and (2) above is complex when (1) is isolated from (2) and highly complex when (1) and (2) are merged together into one process or experience.

Vox populi and the Delphi method cannot be formulated using mathematics. The outcome may a binary one (“yes” or “no”), but the process leading to “correct” or “incorrect” is not one that can be described by an algorithm. Even the makers of “The Matrix” had to change the formula to yield a better outcome, and the formula needed tweaking all the time!

Because we have entered a scientific process that can be described as vox populi, the wisdom of crowds, we realize the critique against the outcomes – often called “the science” – can be summed up by the usual factors that argue against the polling method. I have for about two decades now worked on vox populi related issues in very big data sets. It gives me some familiarity with the discussion of scientific method, even if my field is not audio related.

My user name is svart-hvitt which means black-white in Norwegian. I chose this user name because of my fascination with science that takes the form of correct-incorrect, like a binary one-zero process. At the same time being in the know that the binary one-zero utcome is a drifting one. I also took the name because I am intrigued by the fact that our utilization of digital ones and zeros are able to represent reality in a convincing manner, while at the same time knowing that “this is not a pipe, it’s a picture of a pipe” (see my avatar).

Science is about getting it about right when we try and describe the world, as Isaac Asmivov brilliantly explained in the essay “The Relativity of Wrong”. He wrote:

“In short, my English Lit friend, living in a mental world of absolute rights and wrongs, may be imagining that because all theories are wrong, the earth may be thought spherical now, but cubical next century, and a hollow icosahedron the next, and a doughnut shape the one after.

What actually happens is that once scientists get hold of a good concept they gradually refine and extend it with greater and greater subtlety as their instruments of measurement improve. Theories are not so much wrong as incomplete”.
Source: https://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm

I urge every ASR member to read the full story as it goes to the core of the scientific process., dealing with the naïve protests by a young student.

Asimov’s use of the word “incomplete” is critical here. When pointing out that ASR’s go to source of audio science may be incomplete, while also being potentially subject to biases (like position related sound fields, i.e. factor (1) above, funding etc.), it’s as if hell breaks loose.

Previously, @oivavoi wrote:

“But take the issue of the dipole speaker, for example. In Harman studies, no good. In one of Søren Bech's studies, however, the dipole received the highest rating given a particular placement, and the worst rating, given a different placement”.
Source: https://www.audiosciencereview.com/...s-and-smooth-off-axis.8090/page-4#post-199430

Instead of unleashing an interesting discussion of Harman’s vox populi process, @oivavoi was forced to take a defensive position, as if one needs to apologize for bringing up critique of Harman’s methods and research results. The paper that @oivavoi quoted didn’t come into the discussion, even if if contains much of interest to this debate.
5D95281F-E3CB-4978-BBF5-A77C5FD018D2.jpeg

Take a look at the excerpt from the article (Evans et al., 2009) above. The table shows at least one obvious weakness of the Harman research; the vox populi process was carried out from one loudspeaker position only. The researchers wrote:

“It is evident that the dependence of listeners’ fidelity ratings on position (and room) is also important. Whilst the dipole is rated as worst in Position 2 (less than 1m from the back wall, central), it is rated as best when moved to Position 1 (over 1m from back and side wall). This suggests that the perceived influence of directivity is de- pendent on both position and room type (…) It is also clear that investigations have been limited based upon the nature of the testing arrangement. The use of ‘clinical’ test environments is arguably not representative of true listening scenarios, and whilst the measured reverberation time may be similar to a domestic listening space, the nature of reflections in many standardised listening rooms are not. Also, the majority of tests are conducted with the listener remaining in a fixed ’sweet-spot’ position. If directivity is to be investigated fully, then listening at more than one position should be included, in order to exploit the characteristic traits of each radiation type — one type of directivity may pro- mote well-balanced timbral and spatial listening across a room, however this would be overlooked with traditional testing methods”.
Source: https://www.researchgate.net/public..._sound_quality_-_a_review_of_existing_studies

The table also shows that research is as much about getting an overview of different voices instead of seeking a favorite voice. That’s why research articles formally contain a part dedicated to literature overview. Meta research articles follow in the same path, where the entire article is devoted to existing research to make a sum-of-the-evidence judgment.

The concept of neutral reproduction of sound has been us for ages. People have searched for colour free sound for over 100 years and Harman have shown that vox populi on average prefers neutral to coloured. However, to reduce factors (1) and (2) above to “frequency response, frequency response and frequency response” is incomplete. It may work as an enticing marketing story if your goal is to push boxes at the highest rate possible, but from a scientific point there is more to factors (1) and (2) above than frequency response.

On the matter of directivity, taken from the Evans et al. (2009) article that @oivavoi quoted previously, the authors concluded thusly:

“An extensive review of studies and opinions regarding the listener response to loudspeaker directivity has been presented, and it is evident that no detailed conclusions with regard to this matter have been established. Whilst some of the literature indicates small preferential trends, most provides little insight and this can be attributed to the limited nature of the tests carried out. The authors propose to conduct a range of more specific tests which will consider the key research questions that have resulted from other studies, namely the isolation of the directivity feature alone, its influence on different auditory attributes and the nature of listening tests conducted”.

Please note that one of the authors of that article, Søren Bech, was one of the co-authors of the 2017 JAES article I brought up earlier, where the authors wrote:

“Loudspeaker specifications have traditionally described the physical properties and characteristics of loudspeakers: frequency response, dimensions and volume of the cabinet, diameter of drivers, impedance, total harmonic distortion, sensitivity, etc. Few of these directly describe the sound reproduction and none directly describe perception of the reproduction, i.e., takes into account that the human auditory system is highly non-linear in terms of spectral-, temporal-, and sound level processing (see, e.g., [3]). This disconnect between specifications and perception have made it challenging for acousticians and engineers (and consumers) to predict how a loudspeaker will sound on the basis of these specifications”.
Source: http://www.aes.org/e-lib/browse.cfm?elib=18729

Bech is professor of audio perception at Aalborg University, director of research for Bang & Olufsen and a member of government expert groups (https://www.linkedin.com/in/s%F8ren-bech-8882aa4/). So Bech is hardly a person who would fall victim of audiophoolery, which I have been accused of when I quoted from his research.

Science is a more complex than a binary process of mathematical properties, a solution waiting for a philosophical answer. “Frequency response, frequency response and frequency response” is an enticing solution to the sound reproduction problem; as enticing as it is incomplete.

This explains too, why I have chosen flat and smooth speakers of excellent vertical and horizontal directivity properties, but still have questions that go beyond the incomplete frequency response answer.
 

Cosmik

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@Cosmik is in the camp of pure mathematics, a camp which I would call “philosophical” not “scientific”.
The try-it-and-see (a.k.a. "scientific") methodology cheats: it purports to respond only to what people like (a.k.a. "prefer") but it starts from a known 'philosophical' position and doesn't deviate very far from it. The ideal amplifier transfer function has already been determined mathematically, and ditto the DAC. Ditto the speaker transducer (all speaker drivers are designed to have basically the same linear transfer function within their range). So the scientists who claim to be investigating empirically have already submitted to 'philosophy' and are just tinkering around the edges.

They can't 'fail' because they don't deviate far from the philosophical starting point. But nor can they 'succeed' because they are essentially blundering around in a world of astronomical 'dimensionality' with no way to map it (except for asking people to choose among an infintesimal selection within an infinite space). For this reason, the 'vox populi' notion appears to 'work' in that after 100 years we still seem to prefer the same core system. But really it is a triumph of philosophy because the philosophy was always correct, and was the only way to create a viable system in the first place. The science can only ask people what they like if a viable system exists, and the 'dimensionality' opened up by deviating from the philosophical/mathematical neutral is so huge that the scientific approach immediately heads off into the noise.

In another 100 years of audio progress, we will still be using the same brilliant-sounding system based on linearity, and speakers with flat frequency response and neutral dispersion, and all scientific attempts to 'discover' something else will be forgotten.
 

Xulonn

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“An extensive review of studies and opinions regarding the listener response to loudspeaker directivity has been presented, and it is evident that no detailed conclusions with regard to this matter have been established.

...and likely will never be. As a science-minded person, I accept the conclusion that predicting sonic preferences from measurements can be quite difficult. I am aware that Harman's research is oriented towards enhancing speaker sales to specific market segments, and not simply basic research in a quest for pure knowledge. There appears to be significant elements of basic research even in Harman's applied audio research program, especially in the area of identifying possible "missing factors" that might ultimately influence personal preferences and motivations for purchasing speakers. I would also assume that Harman includes extensive listening tests, e.g. subjective evaluation - in coordination with their engineering efforts, and does not rely solely on measurements to design speakers.

Unless something is physically changed, the sonic environment and sound-field at a given listening position with a given piece of music played at the same exact level will be a constant. However, the response as "sonic perception" by any human or group of humans - let alone various persons - will vary widely according to mood, state of mind, level of energy (tired and less responsive vs alert and focused), amount of wax in ear canals, etc. Even the specific task of detecting sonic differences can vary from hour-to-hour, day-to-day, and definitely for longer time periods. (Amir or Floyd - can you comment on that assumption by me?)

I assume that Harman researchers are tasked with looking for trends and patterns in human preferences - and not focused solely on measurements and statistical analysis. Capitalism and business interests likely determine that the ultimate goal of Harman research is to help design and market loudspeakers to various market segments and increase revenue. The accusations that "people here at ASR" consider Harman's findings to be gospel is puzzling. I simply see it as the currently favored research findings even though is performed by a business organization. It is a bit unusual that the results of the research are made public, but the conclusions of any research effort are always subject to revision if and when further research contradicts them - if such research can be confirmed and repeated.

The carefully presented image of Harman's Revel loudspeakers, supported by reviewer and customer comments - seems to be working on me currently. I have a strong attraction to Harman's Revel speakers, especially the 206 and 208 models with their gorgeous (to me) wood-veneer cabinets. (I love art, and place a high value on my perception of what I consider to be attractive design.)

When I try a bit of introspection with respect to this desire to own a pair of used Revel 206's, I can find no logical reason to support it, and I don't believe that my knowledge of Harman's research program is a factor. I have never heard the Revel 206's in a double blind - or any other comparison. But something has triggered my desire - even though I cannot afford such "luxuries" as a retiree living on a pension. It is worth noting, however, that positive comments about the Revel 206/208 series here at ASR by members I respect adds a lot to the credibility aspect for me.

In the meantime, my truly excellent little loudspeakers - a pair of Paradigm Atom v6 Monitors - provide everything I "need" sonically in terms of accuracy and clarity. (They just don't have that extra 24Hz of bass and a gorgeous wood-veneer cabinet.)
 

svart-hvitt

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The try-it-and-see (a.k.a. "scientific") methodology cheats: it purports to respond only to what people like (a.k.a. "prefer") but it starts from a known 'philosophical' position and doesn't deviate very far from it. The ideal amplifier transfer function has already been determined mathematically, and ditto the DAC. Ditto the speaker transducer (all speaker drivers are designed to have basically the same linear transfer function within their range). So the scientists who claim to be investigating empirically have already submitted to 'philosophy' and are just tinkering around the edges.

They can't 'fail' because they don't deviate far from the philosophical starting point. But nor can they 'succeed' because they are essentially blundering around in a world of astronomical 'dimensionality' with no way to map it (except for asking people to choose among an infintesimal selection within an infinite space). For this reason, the 'vox populi' notion appears to 'work' in that after 100 years we still seem to prefer the same core system. But really it is a triumph of philosophy because the philosophy was always correct, and was the only way to create a viable system in the first place. The science can only ask people what they like if a viable system exists, and the 'dimensionality' opened up by deviating from the philosophical/mathematical neutral is so huge that the scientific approach immediately heads off into the noise.

In another 100 years of audio progress, we will still be using the same brilliant-sounding system based on linearity, and speakers with flat frequency response and neutral dispersion, and all scientific attempts to 'discover' something else will be forgotten.

Well, I think the vox populi type of research is interesting. And my point boils down to this:

Say Salón is preferred over M2. How should one use one’s general insight into speaker design to predict such an outcome? If I am not mistaken, people were surprised at the majority of listeners prefering the Salon in the much talked about audio society blind test. Which of the two speakers do you think is the better based on your insights? Do you think «frequency response» alone could predict the outcome of the audio society blind test?
 

Biblob

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Well, I think the vox populi type of research is interesting. And my point boils down to this:

Say Salón is preferred over M2. How should one use one’s general insight into speaker design to predict such an outcome? If I am not mistaken, people were surprised at the majority of listeners prefering the Salon in the much talked about audio society blind test. Which of the two speakers do you think is the better based on your insights? Do you think «frequency response» alone could predict the outcome of the audio society blind test?
Take the amount of variables @Xulonn mentioned. The fact that in a relative casual test the Salons were preffered, does'nt have to mean a lot. It could well mean that both speakers are technically excellent but the dispersion makes the differrence in taste. That would mean that in another test the M2's could be preffered. I'd say, take those results with a pinch of salt.
 
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MSNWatch

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FREQUENCY RESPONSE: EN ENTICING MARKETING STORY

! Warning! - - - long post!!! - - -

@Kvalsvoll, it’s not as if I am unfamiliar with the history or philosophy (for example epistemology) of science. You wrote:

«In science there is one correct answer, and then all the other answers are simply wrong. And the decision on what is correct and what is wrong is based in scientifical technical evidence, and the decision process in itself is based on logic. So there is no middle way».

What you describe here is actucally a binary system, with only two outcomes, one or zero, absolutely correct or absolutely wrong. Limited numbers of states can be described by pure mathematics. If all properties can be fully predicted by pure logic alone, we don’t need experiments to confirm our beliefs or wisdom. I believe @Cosmik is in the camp of pure mathematics, a camp which I would call “philosophical” not “scientific”.

Reproduction of sound is HIGHLY complex as it is a result of factors such as:

(1) The sound field coming from loudspeaker can be formulated by complex functions, and
(2) Our perception of sound follows a series of complex cognitive processes.

In other words, the prediction of reproduced sound – which means combining (1) and (2) above – is so complex one could liken it to opening a can of worms. However, smart people dealing with complexity have had a recipe for ages: Vox populi. In 1907, Francis Galton, who according to Wikipedia was a “an English Victorian era statistician, polymath, sociologist, psychologist, anthropologist, eugenicist, tropical explorer, geographer, inventor, meteorologist, proto-geneticist, and psychometrician”, had to revisit his estimations of the wisdom of the public. At the annual show of the West of England Fat Stock and Poultry Exhibition people had a chance to guess the weight of an ox. The most correct estimates won prizes. Surprised by the outcome of the public’s guesses, Galton wrote:

“It appears, then, that in this particular instance, that the vox populi is correct to within 1 percent of the real value (…) The result is, I think, more creditable to the trustworthiness of a democratic judgment than might have been expected”.
Source: http://galton.org/essays/1900-1911/galton-1907-vox-populi.pdf

The polling method was later refined by none other than the Project RAND to find fast solutions to complex problems utilizing the power of group judgment, by gathering a group of experts (see: https://en.m.wikipedia.org/wiki/Delphi_method). Needless to say, RAND was populated by the best science people, with the aim of winning the (cold) war. In other words, they didn’t search for a solution as if the outcome were a binary, philosophical one, but a forecasting solution that was adaptive, robust and able to deal with complexity.

So it is in this tradition, the democratic vox populi line of thinking, that audio researchers use polls too instead of mathematics alone to find solutions to the sound reproduction problem, given the fact that predicting both (1) and (2) above is complex when (1) is isolated from (2) and highly complex when (1) and (2) are merged together into one process or experience.

Vox populi and the Delphi method cannot be formulated using mathematics. The outcome may a binary one (“yes” or “no”), but the process leading to “correct” or “incorrect” is not one that can be described by an algorithm. Even the makers of “The Matrix” had to change the formula to yield a better outcome, and the formula needed tweaking all the time!

Because we have entered a scientific process that can be described as vox populi, the wisdom of crowds, we realize the critique against the outcomes – often called “the science” – can be summed up by the usual factors that argue against the polling method. I have for about two decades now worked on vox populi related issues in very big data sets. It gives me some familiarity with the discussion of scientific method, even if my field is not audio related.

My user name is svart-hvitt which means black-white in Norwegian. I chose this user name because of my fascination with science that takes the form of correct-incorrect, like a binary one-zero process. At the same time being in the know that the binary one-zero utcome is a drifting one. I also took the name because I am intrigued by the fact that our utilization of digital ones and zeros are able to represent reality in a convincing manner, while at the same time knowing that “this is not a pipe, it’s a picture of a pipe” (see my avatar).

Science is about getting it about right when we try and describe the world, as Isaac Asmivov brilliantly explained in the essay “The Relativity of Wrong”. He wrote:

“In short, my English Lit friend, living in a mental world of absolute rights and wrongs, may be imagining that because all theories are wrong, the earth may be thought spherical now, but cubical next century, and a hollow icosahedron the next, and a doughnut shape the one after.

What actually happens is that once scientists get hold of a good concept they gradually refine and extend it with greater and greater subtlety as their instruments of measurement improve. Theories are not so much wrong as incomplete”.
Source: https://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm

I urge every ASR member to read the full story as it goes to the core of the scientific process., dealing with the naïve protests by a young student.

Asimov’s use of the word “incomplete” is critical here. When pointing out that ASR’s go to source of audio science may be incomplete, while also being potentially subject to biases (like position related sound fields, i.e. factor (1) above, funding etc.), it’s as if hell breaks loose.

Previously, @oivavoi wrote:

“But take the issue of the dipole speaker, for example. In Harman studies, no good. In one of Søren Bech's studies, however, the dipole received the highest rating given a particular placement, and the worst rating, given a different placement”.
Source: https://www.audiosciencereview.com/...s-and-smooth-off-axis.8090/page-4#post-199430

Instead of unleashing an interesting discussion of Harman’s vox populi process, @oivavoi was forced to take a defensive position, as if one needs to apologize for bringing up critique of Harman’s methods and research results. The paper that @oivavoi quoted didn’t come into the discussion, even if if contains much of interest to this debate.
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Take a look at the excerpt from the article (Evans et al., 2009) above. The table shows at least one obvious weakness of the Harman research; the vox populi process was carried out from one loudspeaker position only. The researchers wrote:

“It is evident that the dependence of listeners’ fidelity ratings on position (and room) is also important. Whilst the dipole is rated as worst in Position 2 (less than 1m from the back wall, central), it is rated as best when moved to Position 1 (over 1m from back and side wall). This suggests that the perceived influence of directivity is de- pendent on both position and room type (…) It is also clear that investigations have been limited based upon the nature of the testing arrangement. The use of ‘clinical’ test environments is arguably not representative of true listening scenarios, and whilst the measured reverberation time may be similar to a domestic listening space, the nature of reflections in many standardised listening rooms are not. Also, the majority of tests are conducted with the listener remaining in a fixed ’sweet-spot’ position. If directivity is to be investigated fully, then listening at more than one position should be included, in order to exploit the characteristic traits of each radiation type — one type of directivity may pro- mote well-balanced timbral and spatial listening across a room, however this would be overlooked with traditional testing methods”.
Source: https://www.researchgate.net/public..._sound_quality_-_a_review_of_existing_studies

The table also shows that research is as much about getting an overview of different voices instead of seeking a favorite voice. That’s why research articles formally contain a part dedicated to literature overview. Meta research articles follow in the same path, where the entire article is devoted to existing research to make a sum-of-the-evidence judgment.

The concept of neutral reproduction of sound has been us for ages. People have searched for colour free sound for over 100 years and Harman have shown that vox populi on average prefers neutral to coloured. However, to reduce factors (1) and (2) above to “frequency response, frequency response and frequency response” is incomplete. It may work as an enticing marketing story if your goal is to push boxes at the highest rate possible, but from a scientific point there is more to factors (1) and (2) above than frequency response.

On the matter of directivity, taken from the Evans et al. (2009) article that @oivavoi quoted previously, the authors concluded thusly:

“An extensive review of studies and opinions regarding the listener response to loudspeaker directivity has been presented, and it is evident that no detailed conclusions with regard to this matter have been established. Whilst some of the literature indicates small preferential trends, most provides little insight and this can be attributed to the limited nature of the tests carried out. The authors propose to conduct a range of more specific tests which will consider the key research questions that have resulted from other studies, namely the isolation of the directivity feature alone, its influence on different auditory attributes and the nature of listening tests conducted”.

Please note that one of the authors of that article, Søren Bech, was one of the co-authors of the 2017 JAES article I brought up earlier, where the authors wrote:

“Loudspeaker specifications have traditionally described the physical properties and characteristics of loudspeakers: frequency response, dimensions and volume of the cabinet, diameter of drivers, impedance, total harmonic distortion, sensitivity, etc. Few of these directly describe the sound reproduction and none directly describe perception of the reproduction, i.e., takes into account that the human auditory system is highly non-linear in terms of spectral-, temporal-, and sound level processing (see, e.g., [3]). This disconnect between specifications and perception have made it challenging for acousticians and engineers (and consumers) to predict how a loudspeaker will sound on the basis of these specifications”.
Source: http://www.aes.org/e-lib/browse.cfm?elib=18729

Bech is professor of audio perception at Aalborg University, director of research for Bang & Olufsen and a member of government expert groups (https://www.linkedin.com/in/s%F8ren-bech-8882aa4/). So Bech is hardly a person who would fall victim of audiophoolery, which I have been accused of when I quoted from his research.

Science is a more complex than a binary process of mathematical properties, a solution waiting for a philosophical answer. “Frequency response, frequency response and frequency response” is an enticing solution to the sound reproduction problem; as enticing as it is incomplete.

This explains too, why I have chosen flat and smooth speakers of excellent vertical and horizontal directivity properties, but still have questions that go beyond the incomplete frequency response answer.


Well, I think the vox populi type of research is interesting. And my point boils down to this:

Say Salón is preferred over M2. How should one use one’s general insight into speaker design to predict such an outcome? If I am not mistaken, people were surprised at the majority of listeners prefering the Salon in the much talked about audio society blind test. Which of the two speakers do you think is the better based on your insights? Do you think «frequency response» alone could predict the outcome of the audio society blind test?

Anecdotal evidence versus larger scale trials which AFAIK only the Harman group has done in a systematic way. Would you take a medicine that was shown to be effective in a 5-10 patient trial or one that was shown to be effective in a systematically done trial of over a hundred patients? Bech may be distinguished in his field but in fields like medicine, expert opinion is considered the weakest form of evidence and certainly takes a backseat to properly done large scale blinded randomized studies.

Show us actual data from studies of the caliber of the Harman group that comes up with different conclusions then that's worth discussing. Otherwise it's a lot of brownian motion.
 

Juhazi

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To svart-hvitt (jag visste vad det menar), hard science might be B/W but hearing stereo is cognitive or behavioral science! My expertise medicine as well - not to mention psychology and psychiatry!
 

Cosmik

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To svart-hvitt (jag visste vad det menar), hard science might be B/W but hearing stereo is cognitive or behavioral science! My expertise medicine as well - not to mention psychology and psychiatry!
Hearing stereo may not totally be cognitive or behavioural science: Blumlein stereo creates a real, physical, probably measurable, interaural delay at the ears from a level-only difference at the speakers. But a further refinement may be that the brain cancels out the cancellation and comb filtering thus caused because it is a mirror image at the ears - or something like that.

Now whether Blumlein knew about this (philosphically/mathematically) when he invented it, I don't know. It was always going to be invented that way, I guess (big cinema screen, sounds needed from left, right and middle needing at least two speakers), but it works out so much better than I would have guessed it would.

Again, we are still using it going on for 100 years after it was invented, and I doubt there'll be any change in it in the future.
 

amirm

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...and likely will never be. As a science-minded person, I accept the conclusion that predicting sonic preferences from measurements can be quite difficult. I am aware that Harman's research is oriented towards enhancing speaker sales to specific market segments, and not simply basic research in a quest for pure knowledge.
Not true at all. This research originated when Dr. Toole was at nonprofit National Research Council of Canada (NRCC). Harman test data simply expands on it as there were more resources when Dr. Toole and Olive joined the company. If you look at the research papers, tons of them are from NRC days with exactly the same conclusions.

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Really guys, let's not keep reliving this. This is proper research, grounded in the fundamental question of what listeners prefer in controlled testing. The data is offered to the world to benefit from it, competitors and all.
 
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