Single photons in some cases. 1 lumen is 1015 photons/second, so I have no idea where that "1000" comes from.
Yes, but beyond the dynamic range of 60dB?Sure it has. A number of us lighting designers were doing that back in the 1980s. Pushing the limits of visual perception. I was quite entertaining - to us, at least.
If a whole industry is based on accepting less than 60dB S/N as being sufficient for getting the message across, for decades, I don't think a specific research paper done to "prove" this tells one much. Imagine if at the advent of tape recording a few scientists did experiments to justify similar quality levels for that media, what value that would have today ...
Speaking of which, they "proved" that you didn't need extended FR as I recall -- I think the bedding down with time, of concepts, tells one where the "truth" is ...
Edit: that 60dB, 1 in 1,000, means what it means: something visual that depends on the ability for the eye to quickly discern a gradation finer than that is going to fail. Only if the whole envelope of the dynamic range that is being used at the moment is raised or lowered will there be usefulness; if one is prepared to spend minutes allowing the eye to acclimatise then it will be capable of jumping over high walls in terms of registering light intensities ...
Frank
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Well, things are never quite what they seem at first glance ... hmmm, wonder if anyone's thought of that concept before ... could be a patent in it, or maybe a Nobel Prize ...
Meaning, I looked further on the eye issue and dynamic range, and it's a nest of worms: absolutely everyone is stating different figures, which I guess means, it depends ... just like with the ear, whether the butterfly flapped away on the other side of the world could make a difference ... bugger!!
The best, concise rundown I've come across so far is here: Eyes On The Lake ...
Which means that the dynamic range is quoted on the net as anything between 6 and 20 stops, in fact 24 is the best I saw ... pick a number that suits ...
Frank
Meaning, I looked further on the eye issue and dynamic range, and it's a nest of worms: absolutely everyone is stating different figures, which I guess means, it depends ... just like with the ear, whether the butterfly flapped away on the other side of the world could make a difference ... bugger!!
The best, concise rundown I've come across so far is here: Eyes On The Lake ...
There's a perfect correlation with a vision "stop" and digital bit ...
Which means that the dynamic range is quoted on the net as anything between 6 and 20 stops, in fact 24 is the best I saw ... pick a number that suits ...
Frank
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Can you hear a mosquito buzzing next to a jack-hammer? No.
The ear has active damping, in part to protect it from the sounds of chewing and use of voice.
On a good day, human ear has maybe 47dB of useable dynamic range.
But in the post prior I attended to my "misunderstanding" of how the vision adaptation mechanism worked ... and the hearing system has something similar as you say. So, the exercise in understanding now develops a new phase - how rapidly does, in particular, the hearing system adapt to enormous, or lesser, variations in intensity.
Thinking back, many years ago, to listening to intense firecrackers going off, probably 140dB peaks - this was an enormous Chinese hanging cracker tree at about 20 feet - I was "deaf" for about 15 minutes afterwards ... was an extreme of this. So if you hear a few peaks at 120dB does that restrict your ability to hear details at 60dB a few seconds later? What if the peaks were 100dB, can you hear "micro" stuff at 40dB that same time period later? What if the delay was 1 sec, or 10 secs? How many peaks, at a certain intensity, cause the "damping" to alter? How does it vary with sex, age, physical condition, amount of alcohol in the system, etc, etc, etc ...?
Frank
Thinking back, many years ago, to listening to intense firecrackers going off, probably 140dB peaks - this was an enormous Chinese hanging cracker tree at about 20 feet - I was "deaf" for about 15 minutes afterwards ... was an extreme of this. So if you hear a few peaks at 120dB does that restrict your ability to hear details at 60dB a few seconds later? What if the peaks were 100dB, can you hear "micro" stuff at 40dB that same time period later? What if the delay was 1 sec, or 10 secs? How many peaks, at a certain intensity, cause the "damping" to alter? How does it vary with sex, age, physical condition, amount of alcohol in the system, etc, etc, etc ...?
Frank
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The stapedius reflex, like any reflex, varies with the individual.
Answering for myself, the ability to hear low level detail after exposure to high level peaks is dependent on the frequency content of either.
The louder the level in the 2000 to 5000Hz range for me, the less dynamic level change I can perceive in that range, and the longer the stapedius reflex persists.
Loud level (120 dB) at frequencies below around 120 Hz have very little effect on my dynamic range in the 2000 to 5000Hz region.
If you are interested in more details on the subject, check out this article and the sources:
Acoustic reflex - Wikipedia, the free encyclopedia
Regarding the OP subject "Inherent sonic characteristics that can't be measured", though sonic characteristics of virtually anything the ear is subjected to can be accurately measured, since hearing (and opinions) take place in the brain, measurements of speakers will not determine whether their sound will be acceptable to anybody not sharing the same opinion of what is desirable.
Having heard thousands of different systems, and having measured responses of hundreds, I can reliably predict by measurement many attributes I find objectionable to listen to, while others might find the same attributes quite enjoyable.
The nice thing about measurement is it can save money and time, one does not have to purchase and "live with" a speaker to identify basic faults that one knows will be eventually found objectionable.
Art
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The things we hear but cannot measure take place in the audio pathway after the inner ear; that is the cochlear nerve, the three cochlear nuclei in the brainstem, the two superior olivary complexes, the lateral lemnisus, the intermediate acoustic stria, and then onward to higher brain parts various.
That is, neurology and psychology. We can't measure them so well.
That is, neurology and psychology. We can't measure them so well.
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The last few posts are very interesting, thanks..
I owned N801 speakers 10 years ago and lived with them, miserably, for two years..The biggest issue(there were several) was audible cone breakup in the kevlar midrange..The company's info declared that they operate within the breakup modes but its not audible..
I went on another forum and there was a long discussion(debate) about said problem.. A few other owners had heard it and some said they couldn't hear it.. The majority of the posters had never listened to those speakers before and, not surprisingly after reading this thread, most of that group were adamant that it wasn't possible to hear a problem like this with such a respected product and company..
After selling the N801 I travelled a bit to hear 801D in three different shops. Each setup was unique.. Different amplifiers were used at each location and the cone breakup was very audible and annoying..
You may ask if I'm sure if it was cone breakup?.. I didnt measure it but I assumed it was from the sound of it-like a pressure wave that is audble but dosen't contain the music signal but rides overtop of the music and was distinctlty seperate from the music..
Okay Here's my Stereophile Rant: This is when I stopped reading a magazine with intentionaly absent information.. The N801 was also very edgy sounding with many amplifiers and a very difficult load dispite highish sensitivity.. Magazine review should have stated " Forget about personal taste, You will be f'd unless you select a very specific amplifier to keep this speaker from sounding terrible." and on and on to make people aware... Kelvlar Midrange issue- well maybe some were unable to hear it
I owned N801 speakers 10 years ago and lived with them, miserably, for two years..The biggest issue(there were several) was audible cone breakup in the kevlar midrange..The company's info declared that they operate within the breakup modes but its not audible..
I went on another forum and there was a long discussion(debate) about said problem.. A few other owners had heard it and some said they couldn't hear it.. The majority of the posters had never listened to those speakers before and, not surprisingly after reading this thread, most of that group were adamant that it wasn't possible to hear a problem like this with such a respected product and company..
After selling the N801 I travelled a bit to hear 801D in three different shops. Each setup was unique.. Different amplifiers were used at each location and the cone breakup was very audible and annoying..
You may ask if I'm sure if it was cone breakup?.. I didnt measure it but I assumed it was from the sound of it-like a pressure wave that is audble but dosen't contain the music signal but rides overtop of the music and was distinctlty seperate from the music..
Okay Here's my Stereophile Rant: This is when I stopped reading a magazine with intentionaly absent information.. The N801 was also very edgy sounding with many amplifiers and a very difficult load dispite highish sensitivity.. Magazine review should have stated " Forget about personal taste, You will be f'd unless you select a very specific amplifier to keep this speaker from sounding terrible." and on and on to make people aware... Kelvlar Midrange issue- well maybe some were unable to hear it
Thanks for that, Art ...
The down side of what I quoted, is that the message you present is that everyone has to "learn", by whatever means, what are the significant characteristics as revealed by measurements that they're personally sensitive to.
Most I suspect will still follow the journey of purchase after purchase after purchase to determine them ...
Frank
Had a look at the stapedius reflex reference, very interesting material ... it explains a lot that I knew "instinctively" ...
Particularly the item about one's ability to pre-attenuate the sensitivity; and about birds, I have wondered at times why they don't deafen themselves ...!! We have white cockatoos here, and their call is ferocious, I note the record, for a non-Oz species, is 135dB!! At times we get enormous flocks of cockies wheeling about overhead, around and around they go, every individual in full voice -- this is wake the dead material ...!!
Frank
Particularly the item about one's ability to pre-attenuate the sensitivity; and about birds, I have wondered at times why they don't deafen themselves ...!! We have white cockatoos here, and their call is ferocious, I note the record, for a non-Oz species, is 135dB!! At times we get enormous flocks of cockies wheeling about overhead, around and around they go, every individual in full voice -- this is wake the dead material ...!!
Frank
Art - a wise post.
A further point that I would make is about "expectation". We tend to like things that meet our "expectation". This is true of loudspeakers as well. Unless you have heard some really good systems and even then for an extended period of time, ones "expectation" may be for a lessor quality. Measurements tell us when things are moving in the right direction even while our brains may be telling us something else.
Learning how to correlate measurement with what you are hearing does not come very quickly.
I'm pretty good at it, but at my age now my hearing is getting to be so poor that nothing sounds as good as my memories..
Art
Yes, there is: http://www2.ak.tu-berlin.de/~akgrou...MQFjAA&usg=AFQjCNH0EUYr2BjEGZ_a921zDyi1A-HVIw
Unfortunately in German, I don't know if there's a translation to English.
Summary: in an anechoic room, with distortion below perceptability, and identical frequency response, there is no difference between domes, planars, and other stuff.
From this result follows that all differences heard under real-world applications are from non-linearities, directivity, and frequency response, and not from something esoteric like diaphragm material or extremely low mass.
Unfortunately in German, I don't know if there's a translation to English.
Summary: in an anechoic room, with distortion below perceptability, and identical frequency response, there is no difference between domes, planars, and other stuff.
From this result follows that all differences heard under real-world applications are from non-linearities, directivity, and frequency response, and not from something esoteric like diaphragm material or extremely low mass.
This adress should work:
http://www2.ak.tu-berlin.de/~akgroup/ak_pub/abschlussarbeiten/2010/RotterAndreas_MagA.pdf
http://www2.ak.tu-berlin.de/~akgroup/ak_pub/abschlussarbeiten/2010/RotterAndreas_MagA.pdf
I think that there is a circularity that operates in the way most experts view measurements. They think they know all about how the device under test operates so they just don't measure for certain things. This leaves gaps and crevices for the subjectivists to occupy and propagate their doubts from.
I think I could design a device that would pass the 'standard' tests but still sound terrible. An expert would look at it and say "but an amplifier couldn't possibly do that!" and he'd probably be right, but in a world where people claim to be able to hear distortion at -100dB and the differences between short lengths of wire, I think it is worth testing for pretty much everything, especially if a computerized gizmo could do it 'for free'.
I'm thinking along the lines of why only use sinusoidal test tones or noise for testing a circuit? They immediately leave the test open to the charge that it isn't 'real'. Is the frequency domain the only worthwhile way to characterise an audio device? Why only use resistors as amplifier loads? This is where the experts say "but everyone knows that as long as your load is lower in impedance than the lowest expected dip in speaker impedance, it will give you the worst case! And anyway it's an established standard, now, so too late to change". But is that true? It assumes some knowledge of how every amplifier works and hence leaves a gap for people to propagate doubts about the sound of feedback, stability with varying load and so on.
I think I could design a device that would pass the 'standard' tests but still sound terrible. An expert would look at it and say "but an amplifier couldn't possibly do that!" and he'd probably be right, but in a world where people claim to be able to hear distortion at -100dB and the differences between short lengths of wire, I think it is worth testing for pretty much everything, especially if a computerized gizmo could do it 'for free'.
I'm thinking along the lines of why only use sinusoidal test tones or noise for testing a circuit? They immediately leave the test open to the charge that it isn't 'real'. Is the frequency domain the only worthwhile way to characterise an audio device? Why only use resistors as amplifier loads? This is where the experts say "but everyone knows that as long as your load is lower in impedance than the lowest expected dip in speaker impedance, it will give you the worst case! And anyway it's an established standard, now, so too late to change". But is that true? It assumes some knowledge of how every amplifier works and hence leaves a gap for people to propagate doubts about the sound of feedback, stability with varying load and so on.
Very interesting article!
BUT...
Surely the reproduction from a planar/ribbon/ESL shows different break up 'fingerprints' to those of more conventional drivers?
Since conventional drivers are far more prevalent, doesn't that mean most listeners are accustomed to the break up of conventional drivers, and as a result more sensitive to the break up fingerprint of Ribbon/planar/ESL drivers?
Also 'extremely low mass'...surely that has an effect? With respect to the likelihood of micro-resonance within ultra light diaphragms (like a ribbon) being, I imagine, much greater. I for one, would like to be able to find breakup characteristics of a ribbon-The 'entire diaphragm mass being driven' argument does not negate the possibility of break up IMHO.
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@Rudolf: thanks, whatever happened to my link
@mondogenerator: if every single tweeter system, is it ribbon, esl, AMT or anything, has its own "break up fingerprint", than the frequency response would show it. This was handled in the test, because the frequency response was equalized so that all tweeters had the same.
@mondogenerator: if every single tweeter system, is it ribbon, esl, AMT or anything, has its own "break up fingerprint", than the frequency response would show it. This was handled in the test, because the frequency response was equalized so that all tweeters had the same.
@baseballbat. I dont totally agree. I have seen quite a few drivers where breakup isnt obvious in freq response, but very clear in impedance plots and THD vs freq plots. What I am meandering towards is a possible phenomenon where micro resonance in the near ultrasonic range and beyond, could cause a particular like or dislike of planar/ribbons to various listeners to varying degrees.
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