Hmmm. Auplater, are you suggesting the difference between baffle EnABL and faceplate screwholes is the same as between a bunker-buster and bb gun? I'm genuinely interested in your (or Dave's) take on the physics here as maybe more extreme treatment (e.g. bigger bumps) might make a bigger difference (to keep on topic).
Carl
Re: into the fray
Since I am subscribed to the AudioCircle and others here may be, but are not offering to report detail, I'll post some of Danny's info.
Danny did not limit his listening to 2.5k, he listened to them full-range. He did not feel that measuring at 90 degrees off-axis was warranted since that size driver rolls off dramatically in that range and nothing would be gained. He did measure full-range on-axis and at 20, 40 and 60 degrees, however. Differences were within standard driver tolerances as reported by him.
He reported neither improvement nor just a change, he reported no change, as Bud notes below. He did not listen to them limited to 2.5k for the reason he stated below.
This is not a valid statement for two reasons. One, Danny did measure a difference, it's just that they were within the typical tolerance of production. Two, it's very easy to make any number of measurable differences that are not audible. This has been shown consistently through various research for years. There is a known limit to the audibility of various types of changes. You are aware of this, aren't you Bud?
At the end of his posts he added this:
Just reporting his relevant comments for those who cannot read the entire posting.
Dave
Since I am subscribed to the AudioCircle and others here may be, but are not offering to report detail, I'll post some of Danny's info.
Nanook said:
Danny did not limit his listening to 2.5k, he listened to them full-range. He did not feel that measuring at 90 degrees off-axis was warranted since that size driver rolls off dramatically in that range and nothing would be gained. He did measure full-range on-axis and at 20, 40 and 60 degrees, however. Differences were within standard driver tolerances as reported by him.
He reported neither improvement nor just a change, he reported no change, as Bud notes below. He did not listen to them limited to 2.5k for the reason he stated below.
This is not a valid statement for two reasons. One, Danny did measure a difference, it's just that they were within the typical tolerance of production. Two, it's very easy to make any number of measurable differences that are not audible. This has been shown consistently through various research for years. There is a known limit to the audibility of various types of changes. You are aware of this, aren't you Bud?
At the end of his posts he added this:
Just reporting his relevant comments for those who cannot read the entire posting.
Dave
dlr said:
Gee, thanks...
Here's some "relevant comments" that didn't make the cut.
Bottom line then?
- listening comparison (and measurements) were made between an EnABL'd driver with 1 hour burn in vs. stock driver with 48 hours burn in 🙄
- the significant difference in burn in time renders frequency response plots comparisons inconclusive
- surface reflections from the cabinet make the off axis measurements inconclusive at best
- in his conclusion, the author notes the significance of burn in with regard to measureable effect in the drivers output.
Here is a cached version of the entire posting:
http://74.125.155.132/search?q=cach...opic=59575.msg530173&cd=1&hl=en&ct=clnk&gl=au
I won't lose any sleep over this one.
Cheers,
Alex
dlr
No, I was not aware of that testing. Can you point me to a source please? I am aware of anecdotal comments about 1/2 dB, 1 db and 3 db as "limits" to comprehension of a change. I would be very interested to see information regarding frequency vs amplitude change vs phase change.
Bud
No, I was not aware of that testing. Can you point me to a source please? I am aware of anecdotal comments about 1/2 dB, 1 db and 3 db as "limits" to comprehension of a change. I would be very interested to see information regarding frequency vs amplitude change vs phase change.
Bud
BudP said:
So you are aware. It's not made available freely. You'll have to purchase much if not most of it from the AES and/or other sources. Here's a link for a good paper. I'm sure that there are more recent ones as well. The last I recall reading indicated that for tests to be considered valid, differences between tests had to within +/- 0.25db, but it may depend on the test protocol.
AES paper on The Audibility of Frequency Response Irregularities
JAES Volume 29 Issue 3 pp. 126-131; March 1981
Here's the synopsis:
The research exists and is available. That's just one. It's not all anecdotal. Most of that anecdotal information probably originated from those who read the research papers.
Dave
Edit: Some more references
On the Audibility of Midrange Phase Distortion in Audio Systems
Authors: Lipshitz, Stanley P.; Pocock, Mark; Vanderkooy, John
The Audibility of Doppler Distortion in Loudspeakers
Authors: Allison, Roy; Villchur, Edgar
Synopsis:
dlr,
Thank you Dave. I will purchase at least the one from 1981. I have been aware of the inaudibility of valleys Vs peaks for quite a while.
Soongsc,
Actually, these even more impressive CSD plots were lodged in my brain.
http://www.diyaudio.com/forums/showthread.php?postid=1363355#post1363355
Thank you for the location of more of your work. I suppose I am going to have to actually reread that entire monster thread...sigh.
Bud
Thank you Dave. I will purchase at least the one from 1981. I have been aware of the inaudibility of valleys Vs peaks for quite a while.
Soongsc,
Actually, these even more impressive CSD plots were lodged in my brain.
http://www.diyaudio.com/forums/showthread.php?postid=1363355#post1363355
Thank you for the location of more of your work. I suppose I am going to have to actually reread that entire monster thread...sigh.
Bud
Too technical??
Why not humour us on the "too technical" side...
Some of us have advanced materials science degrees... and hold patents in the electrochemical field..no?? 😀
Chrome plated nickel is what constitutes car bumpers... nothing special there.... please enlighten we heathens...
John L.
soongsc said:
Why not humour us on the "too technical" side...
Some of us have advanced materials science degrees... and hold patents in the electrochemical field..no?? 😀
Chrome plated nickel is what constitutes car bumpers... nothing special there.... please enlighten we heathens...
John L.
I was going to post somthing humorous in response to that remark, but on second thoughts, some people might find it offending.
this line left intentionally blank
yeah...just trying to maintain the bandwidth consumption guidelines for this thread I guess...😀
yeah...just trying to maintain the bandwidth consumption guidelines for this thread I guess...😀
Bud, are you claiming that the noise floor (how do you define that in your mind?) is 90db down? Down from what? How have you determined that the noise floor moved down another 50db, that being an unequivocal statement? I'm asking clear, specific questions directly related to your comments. Given your certitude, I'm sure that you have clear, specific answers.
Dave
Dave,
Noise floor in my usage, refers to the intelligibility of downward dynamic range. This being the low level, wide band signals that carry the physical description information, from musical instruments being played, in a confined space, or out in open air.
The key here is intelligibility. I am well aware that a common noise floor in a home is about 50 db. Most of these noises are blocked by our correlator, as it scans for new threats in our environment. This means that we are actually filtering out this background noise, something our microphones cannot do. This is something we all have experience with and only those folks sitting in meditation, or very frightened for their lives, can overcome.
This correlator is interested in input that can be parsed into descriptions, labeled as threat or not and either ignored or focused on, eventually consciously. This is the portion of the human experience that, while not at all objective or as accurate as a microphone, is still capable of making sense out of what is just the grass at the bottom of a spectral analysis plot.
When a loudspeaker has an intelligibility floor at about 40 db down from transient signal peak, not averaged SPL, the information it would provide below that level becomes noise, but only to a correlated processor. All signals are noise to a microphone as there is no level of correlated intelligibility, in short, all of a microphones input is nonsense. Not being negative here, just drawing a comparison.
This is the place that EnABL provides the bulk of its benefit. It will allow a driver to emit intelligible signals, below a level that was not available before treatment. The correlator can actually track these signals to well below the noise floor, in a quiet room, that has a noise floor comprised of known, labeled and ignored signals.
John K's blink comparison showed this sort of refinement of low level signal coherence, on the steps of the major ringing node at 9 kHz.
http://planet10-hifi.com/johnK-test/
This is not "better" in the normal objective categories. None of the problems observable in a gross analysis of the two plots have been solved. All that has occurred is, that a signal that was decohering as it emitted, was forced to emit as a more coherent representation of the driving signal.
You cannot pick out any refinement of intelligibility in any of the rest of this CSD plot, by looking at the rest of the frequency range. By inductive inference, it is there, and if intelligence was correlating this data represented in the CSD plot the refinements in coherence would be recognized.
So, this is a description of noise floor in relation to EnABL and what its uses are. Not an objective noise floor bound by the limits of machine human interface with an objective and isolated graph. Instead a reference to the ability of a directly perceiving intelligence to track coherent information to below an objective noise floor, in a known and analyzed environment, our listening spaces.
Bud
Noise floor in my usage, refers to the intelligibility of downward dynamic range. This being the low level, wide band signals that carry the physical description information, from musical instruments being played, in a confined space, or out in open air.
The key here is intelligibility. I am well aware that a common noise floor in a home is about 50 db. Most of these noises are blocked by our correlator, as it scans for new threats in our environment. This means that we are actually filtering out this background noise, something our microphones cannot do. This is something we all have experience with and only those folks sitting in meditation, or very frightened for their lives, can overcome.
This correlator is interested in input that can be parsed into descriptions, labeled as threat or not and either ignored or focused on, eventually consciously. This is the portion of the human experience that, while not at all objective or as accurate as a microphone, is still capable of making sense out of what is just the grass at the bottom of a spectral analysis plot.
When a loudspeaker has an intelligibility floor at about 40 db down from transient signal peak, not averaged SPL, the information it would provide below that level becomes noise, but only to a correlated processor. All signals are noise to a microphone as there is no level of correlated intelligibility, in short, all of a microphones input is nonsense. Not being negative here, just drawing a comparison.
This is the place that EnABL provides the bulk of its benefit. It will allow a driver to emit intelligible signals, below a level that was not available before treatment. The correlator can actually track these signals to well below the noise floor, in a quiet room, that has a noise floor comprised of known, labeled and ignored signals.
John K's blink comparison showed this sort of refinement of low level signal coherence, on the steps of the major ringing node at 9 kHz.
http://planet10-hifi.com/johnK-test/
This is not "better" in the normal objective categories. None of the problems observable in a gross analysis of the two plots have been solved. All that has occurred is, that a signal that was decohering as it emitted, was forced to emit as a more coherent representation of the driving signal.
You cannot pick out any refinement of intelligibility in any of the rest of this CSD plot, by looking at the rest of the frequency range. By inductive inference, it is there, and if intelligence was correlating this data represented in the CSD plot the refinements in coherence would be recognized.
So, this is a description of noise floor in relation to EnABL and what its uses are. Not an objective noise floor bound by the limits of machine human interface with an objective and isolated graph. Instead a reference to the ability of a directly perceiving intelligence to track coherent information to below an objective noise floor, in a known and analyzed environment, our listening spaces.
Bud
You're mistaken about the capability of measurement system on two accounts. First, a mic responds to a signal similarly to our ear and is more sensitive. The question is the ability to process that signal. Your second mistake is to say that a measurement system based on a microphone cannot filter background noise in its processing. This is patently wrong and is a specific characteristic of various measurement systems. It is in fact a well-defined characteristic of MLS-based systems among others. Background noise is generally uncorrelated which is what makes it possible for a measurement system to "hear" through the noise, so-to-speak.
You claimed an additional 50db reduction of your "floor". That's what, 90db by your reference? Are you saying that there is unambiguous ability to detect signals that are 90db down from the peaks? At what signal level are these peaks? Remember, 0db is by definition the minimum level of perception of a human with good hearing. If the peaks to which you refer were at 90db, not very high of course, but a common listening level, you're saying that somehow the change makes it possible to hear signals in music essentially near 0db in a room with a noise floor of, say, 50db. I don't think so.
This is an absurd statement and somewhat meaningless and nonsense itself. Microphones measure without subjective interpretation or misinterpretations. Which of the two is the result is not based on the measurement system.
It did nothing of the sort. You're making interpretations and inferring things that have no basis in his measurements. I'm surprised that you'd try to make such inferences from "microphone" measurements given your opinion of them.
Dave
That sight has some interesting reading.
This is a good article:
Microphone vs the Ear
This one is a classic:
Mikrodigi 360 Digital Microphone
Cheers,
Alex
This is a good article:
Microphone vs the Ear
This one is a classic:
Mikrodigi 360 Digital Microphone
Cheers,
Alex
Alex from Oz said:
Nothing much new in the first one. Stereo reproduction is flawed. We know that. It focused precisely on my point about how the signal is processed. That page is on reproduction, not the individual mic vs. ear though that was the title. It encompasses the whole chain, including the output side. It's old news.
The second one is interesting. It is supports, rather dramatically, the fact that a microphone can easily be far more sensitive than anyone's ear, certainly now. Precisely what I said earlier as well. It also totally dismisses the arguments about mics and dynamic range issues. Older ones were good, this one is better. Looks like it may allow use of a single mic vs. the varied recording techniques used today.
The difference in that mic is, again, how the signal is processed. It's a further attempt to improve the recording for the reproduction and is an attempt to provide a signal for processing that comes closer to making us believe in an illusion. Certainly worthwhile.
It's all about the signal processing. Thanks for providing a link that directly supports what I have been saying for a while now.
Dave
SimontY said:
At least you're able to display a sense of humour now
Re-read my post. I've added the relevant page that directly supports that from the link provided by Alex.
Dave
I don't think anyone disagrees that mics can pretty much measure what the ear hears. The most complicated and controversial issue is relating measured data with what is perceived from what is heard.
soongsc said:
Look back through the thread and you'll see that this was not the case throughout most of the debate related to mics. I'm not sure that there isn't still disagreement. Has that changed to acceptance now?
Dave
Well, if we try to understand the aspects of this, most that seem to disagree really are under the impression that systems can sound pretty bad even if the published data show performance to be good according to common interpretation of the data. I really don't recall seeing anyone actually pointing out that normal measurement mics are the limitation.dlr said:
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