ronc said:
Ron,
It's pure and simple distortion of the acoustic wave measured by the mic. Input a pure sine wave to the driver motor, out comes an acoustic wave form. Then record and analyze that wave form for distortion.
Bud, I'll respond to your comments tomorrow but the videos you pointed to aren't anything particularly unique. They are just dust responding to surface motion at frequencies high enough to excite modal response. Back in the mid 60's I had a summer job at Campbell’s Soup. One of the machines I helped design used acoustic vibrations (waves) to move a macaroni product up a spiral ramp.
How is the distortion represented? Is it shown in the acoustic domain as distortion in the acoustic output or is it a distortion of the mechanical vibrational modes? Can it predict the distortion imposed in the acoustic domain? Can it be translated into the acoustic domain in some way that is predictive of the acoustic impact, since that is the domain of interest in a driver
You mention "domain: at least four (4) times? Is this a question? Or can you find an analogy? Please dont take my time in something that is only ment to impress others. I am not impressed.
ron
If you have something worthwhile , please contact me offline, out of forum.
You mention "domain: at least four (4) times? Is this a question? Or can you find an analogy? Please dont take my time in something that is only ment to impress others. I am not impressed.
ron
If you have something worthwhile , please contact me offline, out of forum.
Let's remember that distortion simply measures changes from the signal that's provided. If that signal is lacking in qualitative aspects of the source, then distortion can, in fact, BENEFIT the listener IF that distortion more accurately reflects the listener's live experience or what the listener WANTS to hear. Measurements are nice, but what matters is what the listener hears. If you can't separate yourself from the measurements enough to HEAR the things you like, then the emperor has no clothes.
I wonder how many on this thread have actually listened to these mods in a blind side-by-side test with unmodified versions...
Carl
(a lurker on this thread with a strong science and statistics background who also has a liberal arts degree among others).
I wonder how many on this thread have actually listened to these mods in a blind side-by-side test with unmodified versions...
Carl
(a lurker on this thread with a strong science and statistics background who also has a liberal arts degree among others).
Oh, and FWIW, I think my comments above reflect what I hear when I listen to highly (relatively speaking) distorting SET amps. I tend to like them. I am inclined to believe that the reason has to do with something related to HOW they distort the signal relative to how I hear in the real world. They do for the signal what my ears want to hear...
Carl
Carl
Carl,
Welcome to the EnABL juggernaught. Glad to see a 'lurker' come out of the cold...aside from a few exceptions, you will find a friendly group of folks enjoying music and exploring the diverse world of DIY transducer mods. If you feel so inclined, post questions about the process, tools and materials needed, and any driver-specific data and no doubt Bud et. al. will chime in and try to answer. All types here...SET/single driver folks to transistor, Class D and T with multiple drivers and xovers...all are welcome.
t (Richard)
Welcome to the EnABL juggernaught. Glad to see a 'lurker' come out of the cold...aside from a few exceptions, you will find a friendly group of folks enjoying music and exploring the diverse world of DIY transducer mods. If you feel so inclined, post questions about the process, tools and materials needed, and any driver-specific data and no doubt Bud et. al. will chime in and try to answer. All types here...SET/single driver folks to transistor, Class D and T with multiple drivers and xovers...all are welcome.
t (Richard)
Quick and dirty thing to do is subtract the speakers' impulse response from the original one. We get everything.*
Isn't that what we want? Isn't the subtrahend also an impulse response?
What's needed is the power spectrum of of all that's left over.
Get it for treated and untreated speakers at low and high SPL's.
Then we can see the global effect of the treatment.
Then we can see what psychoacoustic effect these remainders might have. Either there are masking effects or there are not. That's easier said than done by amateurs like me.
Looking for ways to do that I found a really interesting paper by Ivo Mateljan, who designed the ARTA software, "Detection of Audible Resonances"
Abstract: The paper discusses the problem of the detection of audible resonances. The basic psychoacoustic researches have shown that the threshold of resonance detection can be classified by resonance level and Q-factor. In this work a third criteria is introduced. It is the energy of the resonance. By analyzing the influence of resonances on the frequency response and group delay, it is shown that it is almost impossible to detect resonances that are near the threshold of audibility. Finally, three common techniques for resonance detection are compared: the cumulative spectral decay, the shaped sine burst decay and the transfer function pole–zero identification. In the conclusion suggestions for the use of the particular method are given
http://www.fesb.hr/~mateljan/arta/papers/im-aaaa2007.pdf
Parts of the paper are in ARTA users' manual. ARTA is good; it doesn't cost a lot an it's free to try out. Going to take me while to understand it well (article and software).
In this connection, the article below was written by a coauthor of one of THE books on psychoacoustics. Very cogent
The Psychoacoustics of Sound-Quality Evaluation - H. Fastl
http://www.zainea.com/fastl.htm
The two power point presentations at the Finnish site have most same diagrams and they are more legible.
http://www.acoustics.hut.fi/teaching/S-89.3320/KA6a.pdf
http://www.acoustics.hut.fi/teaching/S-89.3320/KA6b.pdf
.............................
*What's left over includes contribution from voice coil, spider and surround but what the heck, I said dirty.
Isn't that what we want? Isn't the subtrahend also an impulse response?
What's needed is the power spectrum of of all that's left over.
Get it for treated and untreated speakers at low and high SPL's.
Then we can see the global effect of the treatment.
Then we can see what psychoacoustic effect these remainders might have. Either there are masking effects or there are not. That's easier said than done by amateurs like me.
Looking for ways to do that I found a really interesting paper by Ivo Mateljan, who designed the ARTA software, "Detection of Audible Resonances"
Abstract: The paper discusses the problem of the detection of audible resonances. The basic psychoacoustic researches have shown that the threshold of resonance detection can be classified by resonance level and Q-factor. In this work a third criteria is introduced. It is the energy of the resonance. By analyzing the influence of resonances on the frequency response and group delay, it is shown that it is almost impossible to detect resonances that are near the threshold of audibility. Finally, three common techniques for resonance detection are compared: the cumulative spectral decay, the shaped sine burst decay and the transfer function pole–zero identification. In the conclusion suggestions for the use of the particular method are given
http://www.fesb.hr/~mateljan/arta/papers/im-aaaa2007.pdf
Parts of the paper are in ARTA users' manual. ARTA is good; it doesn't cost a lot an it's free to try out. Going to take me while to understand it well (article and software).
In this connection, the article below was written by a coauthor of one of THE books on psychoacoustics. Very cogent
The Psychoacoustics of Sound-Quality Evaluation - H. Fastl
http://www.zainea.com/fastl.htm
The two power point presentations at the Finnish site have most same diagrams and they are more legible.
http://www.acoustics.hut.fi/teaching/S-89.3320/KA6a.pdf
http://www.acoustics.hut.fi/teaching/S-89.3320/KA6b.pdf
.............................
*What's left over includes contribution from voice coil, spider and surround but what the heck, I said dirty.
Carlp said:
Yes, it's established that SET style 2nd order distortion is very benign in terms of subjectively appreciating the music (not necessarily enjoying it, but accepting it as sounding convincingly close to the original). Whereas solid-state odd order distortion is thoroughly unpleasant sonic poison - we are exquisitely sensitive to even tiny amounts of it and the resulting nasty edge intrudes way beyond what the measured levels might suggest and destroys that feeling of "close to the original".
Hence I am not hopeful for the quest in this thread. We're not even at the stage of agreeing on the nature - or even the presence - of the distortions involved. However, happy to be be surprised here - FrankWW makes sense to me ... but I'm lost with the more complex stuff.
Hi Frank,
>> Quick and dirty thing to do is subtract the speakers' impulse response from the original one. We get everything. What's left over includes contribution from voice coil, spider and surround but what the heck, I said dirty. <<
but I still don't think this test would be directly relatable to the way in which reproduction becomes modified due to cumulative air motion effects arising in series with voice coil impedance; ie. what we hear via music drive with repeated cycles.
However, it could be a good starting point as long as this is borne in mind:-
Distortion/CSD plots etc. made using a 'reference' SS amplifier are not going to be relevent if the driver is then to be driven by a SE tube amplifier, because the way in which resonant energies become trapped/dissipated in the LS system wrt amplifier output is totally different.
A NFB SS amplifier is like a 'mirror' to LS system generated energies, and thus they become concentrated/tuned via the driver's voice coil/cable, whereas a SET amp 'ignores' them and they dissipate naturally (comparative terms).
So results obtained via one type of source only cannot be deemed universal, and this might explain why some hear the effect of EnABL more than others.
Cheers ......... Graham.
>> Quick and dirty thing to do is subtract the speakers' impulse response from the original one. We get everything. What's left over includes contribution from voice coil, spider and surround but what the heck, I said dirty. <<
but I still don't think this test would be directly relatable to the way in which reproduction becomes modified due to cumulative air motion effects arising in series with voice coil impedance; ie. what we hear via music drive with repeated cycles.
However, it could be a good starting point as long as this is borne in mind:-
Distortion/CSD plots etc. made using a 'reference' SS amplifier are not going to be relevent if the driver is then to be driven by a SE tube amplifier, because the way in which resonant energies become trapped/dissipated in the LS system wrt amplifier output is totally different.
A NFB SS amplifier is like a 'mirror' to LS system generated energies, and thus they become concentrated/tuned via the driver's voice coil/cable, whereas a SET amp 'ignores' them and they dissipate naturally (comparative terms).
So results obtained via one type of source only cannot be deemed universal, and this might explain why some hear the effect of EnABL more than others.
Cheers ......... Graham.
Me too, and it's quite a daunting thread to work through. But I'm trying to wade through it as I can. Maybe I'll play around with mods of some cheapo drivers some day...
Interesting comments about SS vs SET 2nd order harmonic distortion from Alan. I'd not heard that before. Again, distortion doesn't bother me. Bad sound does. Hence why I wonder who has heard these mods. Anyone want to chime in with a quick "Me" and "I like" or "I don't like" the mods?
Carl
soongsc said:
An externally hosted image should be here but it was not working when we last tested it.
Wonder how something like this would sound compared to previous posts?
me...i like...
ronc said:
I understand study of root effect. I'd be pleased to have that kind of equipment to use for investigation of it. My questions relate to what matters in the end, the distortion in the acoustic response of the driver. John certainly picked up on the intent of my questions. The systems that are readily available for acoustic measurements will show the distortion in the acoustic domain (please excuse me if this reference disturbs you). However, it sounds as if the types and levels of distortion as observed in the scheme that you described will not show the impact on the acoustic response directly, fine. That was where my questions were leading. Though it would be a useful tool to find the "root effect" to help determine means to improvement, if no one here has or will have a the type of test equipment that you described, in the end it serves us no purpose to know that it's possible to do it.
My questions were also an attempt to get around the condescension in your reply (and now this one), but it evidently did not work as I had hoped.
ronc said:
It was not meant to impress and I likewise am also not impressed. I have no desire to contact you offline at this point in any event. I won't waste my time nor yours in the future. Let's just leave it at that.
Dave
Still working on it. Two things I'd like to optimize some more, one is the resonance around 1.2KHz, the other is that thing above 20KHz. But now as it is, the sound is clean relaxing, good image. Not all large scale performances are good at loud levels, but for low level listening, it's good for all kinds of music. I just thought this would be a good demonstration of process of tuning.jkeny said:
Lots of people talk about audibility of many tweaks. But it is when the CSD in speakers get below a certain level till you really know an improvement from a difference. This is also when you will notice the importance of absolute polarity, zobels, impedance matching a flattening.
Upgrading from toothpaste,😀 some of the tools I use to try various patterns.
The two important things are the sticky dots and the metal strips. The others are tools to work with the strips.
An externally hosted image should be here but it was not working when we last tested it.
The two important things are the sticky dots and the metal strips. The others are tools to work with the strips.
Now I have put some paint on the new victims.
Pictures here:
http://picasaweb.google.dk/klauskaan
I might even have gotten it right this time around 😉
So now I'm waiting for paint to dry
Pictures here:
http://picasaweb.google.dk/klauskaan
I might even have gotten it right this time around 😉
So now I'm waiting for paint to dry
Soongsc,
I take it these are the JX92S speakers you are showing CSD & materials used. You didn't use Aluminium Oxide paint then?
I take it these are the JX92S speakers you are showing CSD & materials used. You didn't use Aluminium Oxide paint then?
Just a general note to all lurkers and subjective optimists here.
Do not be dismayed by the wrangling going on between various factions. Do not be dismayed by the objectivist cautions concerning use of EnABL on your drivers.
We are all on the same page.
The science and engineering types are here because of hope. That the subjective stalwarts are very tenacious in defense of their subjective appraisal of EnABL, just gives them more reason to be insistent about finding the mechanisms at play here.
If, from all camps concerned, we can derive a repeatable set of test parameters and at least a reasonably well understood synthesis of physical parameters, that describe EnABL and it's descendent's, then it can and will be adopted within the engineering driven professional community of manufacturers.
John K, dlr, MJK, SY, ronc and others are doing us all a favor in looking at this with clear eyed proffessionalism. Equally important are Dave Dlugos, ChrisB, T-Head and a small army of other experimenters, for their subjective enthusiasm, for changes provided by EnABL that improve their enjoyment of music.
The third camp is somewhat more mixed. Providing ammunition to the seeming war, on both sides. FrankWW, Grayham Maynard, Lynn Olson and many others are working here to provide help that the other camps haven't the time to look for. And John and AJ have to be included here, humor and derision are useful tools in this sort of endeavor.
And then there is Soongsc. In a very surreptitious fashion, typically inscrutable, he is actually leading this investigation, not I.
So, progress is being made, each of the view points driving and feeding the others. This is how this community is supposed to work and I just cannot get enough of it.
Bud
Do not be dismayed by the wrangling going on between various factions. Do not be dismayed by the objectivist cautions concerning use of EnABL on your drivers.
We are all on the same page.
The science and engineering types are here because of hope. That the subjective stalwarts are very tenacious in defense of their subjective appraisal of EnABL, just gives them more reason to be insistent about finding the mechanisms at play here.
If, from all camps concerned, we can derive a repeatable set of test parameters and at least a reasonably well understood synthesis of physical parameters, that describe EnABL and it's descendent's, then it can and will be adopted within the engineering driven professional community of manufacturers.
John K, dlr, MJK, SY, ronc and others are doing us all a favor in looking at this with clear eyed proffessionalism. Equally important are Dave Dlugos, ChrisB, T-Head and a small army of other experimenters, for their subjective enthusiasm, for changes provided by EnABL that improve their enjoyment of music.
The third camp is somewhat more mixed. Providing ammunition to the seeming war, on both sides. FrankWW, Grayham Maynard, Lynn Olson and many others are working here to provide help that the other camps haven't the time to look for. And John and AJ have to be included here, humor and derision are useful tools in this sort of endeavor.
And then there is Soongsc. In a very surreptitious fashion, typically inscrutable, he is actually leading this investigation, not I.
So, progress is being made, each of the view points driving and feeding the others. This is how this community is supposed to work and I just cannot get enough of it.
Bud
Though it would be a useful tool to find the "root effect" to help determine means to improvement, if no one here has or will have a the type of test equipment that you described, in the end it serves us no purpose to know that it's possible to do it.
I have the equipment, after all its my job. This will be done.
The only question that bothers me is the excessive theory factors that have been brought into this question.
I am totally sure that if i published actual responses that were performed under controled conditions that there would be an ever increasing imput as to the validity of my measurements.
That type action has been the driving force in this question. If you cant understand something , you question.
As far as you and i responding to each other , as i have stated before, i could care less. I work on facts and results from tests, nothing more,nothing less. I am not a popular people person, i never have been and never will be, the only reason companies hire me is i get actual applicable results. This question is no different.
ron
I have the equipment, after all its my job. This will be done.
The only question that bothers me is the excessive theory factors that have been brought into this question.
I am totally sure that if i published actual responses that were performed under controled conditions that there would be an ever increasing imput as to the validity of my measurements.
That type action has been the driving force in this question. If you cant understand something , you question.
As far as you and i responding to each other , as i have stated before, i could care less. I work on facts and results from tests, nothing more,nothing less. I am not a popular people person, i never have been and never will be, the only reason companies hire me is i get actual applicable results. This question is no different.
ron
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