Lama ,Bud,
I'll try your applying your patterns probably tonight, I must go and print it first, as I don't own a printer right now, starting form the outer patterns first. The middle pattern will be very tricky to apply since I use paintbrush , so I'll first practice on my long lost art skill
, please be patient.
Hartono
I'll try your applying your patterns probably tonight, I must go and print it first, as I don't own a printer right now, starting form the outer patterns first. The middle pattern will be very tricky to apply since I use paintbrush , so I'll first practice on my long lost art skill
, please be patient. Hartono
soongsc said:
Hi Soongsc,
I've just discovered this thread and am excited by your experiments on the JX92S speakers and the ENABL techniques in general. I have these speakers to be mounted and was looking to try this particularly as its a reversible mod.
I'm not sure, based on the above quote, if the outcome for these speakers was successful or not (I can't yet fully read the plots intelligently). Are the early reflections a problem in reality or is this a statement about the theoretically ideal?
Is it easy to remove toothpaste without damage to the speakers & is it a long term solution with issues of drying to consider?
Thanks for your excellent expertise in this thread.
jkeny said:
Hi jkeny,
These mods are reversable, the toothpaste is removable using just transparent slides type of plasic film or anything of that sort thin with some stiffness but not so stiff that mishandling will dent the cone. All you have to do is scoop it up, much easier when dried.
The first set of graphs are just to understand what happens as patterns are addid to different locations of the JX92S.
The second try eliminated the cone resonances above 10KHz, this usually results in cleaner and smoother sound in the high frequencies. I have not compared this particular mod with unmodded versions though. This is only because I could not find a system with unmodded JX92S here yet.
The two drivers I modded had exactly the same characteristics, so the location of the rings are the same. It's best to do some measurements prior to modification just to make sure. 1mm difference may not clean these resonances up.
jkeny said:
I would say in a strict sense, the resonances are distributed to much lower levels with this last run, and can be further reduced if more time is spent on it. If you compare the CSDs within 0.38ms, the ridges do not connect with the peaks any more.
From other tests, toothpaste has not fallen off yet. I think if the toothpaste comes off, you can easily reapply it.
Ped,
If you can provide some simple measurements I can provide the sorts of conic sections and treatment guide rings shown here, for a set of Lowthers and a Fostex 127 E, for your Fostex drivers.
http://picasaweb.google.com/hpurvine/FinalLowtherPatternRings
http://picasaweb.google.com/hpurvine/LowthwerDX4EnABLPatterns
http://picasaweb.google.com/hpurvine/Fostex127ETreatment
I need an upper cone diameter at the joint with the surround or end of cone, if the surround is attached to the back side. A second dimension at the joint of cone and voice coil and a third linear dimension between these two points, on the cone surface. These same measurements will be needed for the whizzer cone too.
I use a two pin tipped divider from a mechanical drawing set and dial or digital calipers or a fine gradient ruler in 10th's of an inch or metric scales.
Please note that these will be generic patterns in so far as they do not reflect Sonngsc's important findings concerning where to place the lower ring, or where to add a third ring, to suppress the major systemic frequency null/ringing storage mode area of the cone.
This is an important thing to know and control, but, the generic pattern will make such a significant improvement in what you hear you may not care to experiment further.
Perhaps we can get Sonngsc to add a lower pattern to his controlled experiment cone to see if that impairs the functioning of that intermediate control ring. If the lower, generic ring does not impair the functioning of the control ring this would allow you to pattern the cone, coat it with a single coat of gloss and then use toothpaste and a syringe to add and remove the third pattern until testing shows results.
Applying another pattern in this fashion will allow you to find the ideal position and then use acrylic paint for a more durable pattern. A second and likely third coat of gloss can then be used. Though one of the current uses for the gloss coating is to help distribute this corruption over the cone surface, so that the generic patterns can quench the ringing, the third pattern may eliminate the need for more, or any gloss coatings.
Bud
If you can provide some simple measurements I can provide the sorts of conic sections and treatment guide rings shown here, for a set of Lowthers and a Fostex 127 E, for your Fostex drivers.
http://picasaweb.google.com/hpurvine/FinalLowtherPatternRings
http://picasaweb.google.com/hpurvine/LowthwerDX4EnABLPatterns
http://picasaweb.google.com/hpurvine/Fostex127ETreatment
I need an upper cone diameter at the joint with the surround or end of cone, if the surround is attached to the back side. A second dimension at the joint of cone and voice coil and a third linear dimension between these two points, on the cone surface. These same measurements will be needed for the whizzer cone too.
I use a two pin tipped divider from a mechanical drawing set and dial or digital calipers or a fine gradient ruler in 10th's of an inch or metric scales.
Please note that these will be generic patterns in so far as they do not reflect Sonngsc's important findings concerning where to place the lower ring, or where to add a third ring, to suppress the major systemic frequency null/ringing storage mode area of the cone.
This is an important thing to know and control, but, the generic pattern will make such a significant improvement in what you hear you may not care to experiment further.
Perhaps we can get Sonngsc to add a lower pattern to his controlled experiment cone to see if that impairs the functioning of that intermediate control ring. If the lower, generic ring does not impair the functioning of the control ring this would allow you to pattern the cone, coat it with a single coat of gloss and then use toothpaste and a syringe to add and remove the third pattern until testing shows results.
Applying another pattern in this fashion will allow you to find the ideal position and then use acrylic paint for a more durable pattern. A second and likely third coat of gloss can then be used. Though one of the current uses for the gloss coating is to help distribute this corruption over the cone surface, so that the generic patterns can quench the ringing, the third pattern may eliminate the need for more, or any gloss coatings.
Bud
Soongsc,
I have to admit, I have gotten lost on which rings are where. When you speak of a "ring", do you mean the two rows of blocks or just a single row of blocks? This refers to the pic back on Post #250 and the graphs on Post #255, which I think are related?
I am not particularly conversant with the implications within CSD plots so I am missing what you are pointing to with respect to high frequencies changing. I see the phase angle changing but the frequency curve looks remarkably stable.
Then there is your conversation with John K about the phase information not being quite what is shown.
http://www.diyaudio.com/forums/showthread.php?postid=1240836#post1240836
This left me completely in the dark. Perhaps you would be kind enough explain what some of these questions relate to, as I suspect I am not alone in having a very incomplete understanding of what is being pointed to.
Bud
I have to admit, I have gotten lost on which rings are where. When you speak of a "ring", do you mean the two rows of blocks or just a single row of blocks? This refers to the pic back on Post #250 and the graphs on Post #255, which I think are related?
I am not particularly conversant with the implications within CSD plots so I am missing what you are pointing to with respect to high frequencies changing. I see the phase angle changing but the frequency curve looks remarkably stable.
Then there is your conversation with John K about the phase information not being quite what is shown.
http://www.diyaudio.com/forums/showthread.php?postid=1240836#post1240836
This left me completely in the dark. Perhaps you would be kind enough explain what some of these questions relate to, as I suspect I am not alone in having a very incomplete understanding of what is being pointed to.
Bud
Bud,
Post 250 is the picture of the result from the test series shown in post 255. Post 273 overlaps the graphs.
From the explanation in post 255, you can see the various effects occuring in the sequence the tests were carried out. The only exception was the clean configuration which was done last.
I think the experience in testing and mod is more valuable than this particular result.
Discussion with John covers two things, 1) what do the results of these tests indicate; 2) Cepstral analysis and how to recover the exact driver performance under non-ideal conditions. The first part we seem to agree that phase is varying linearly as the rings of patterns are applied, which seems to indicate a shift in acoustic center (nore clearly understood once one starts doing measurements). The second subject we really don't have any further understanding than what is written. Really trying to figure out how to get the low frequency data out of a mess of reflections in a normal room measuring environment.
Post 250 is the picture of the result from the test series shown in post 255. Post 273 overlaps the graphs.
From the explanation in post 255, you can see the various effects occuring in the sequence the tests were carried out. The only exception was the clean configuration which was done last.
I think the experience in testing and mod is more valuable than this particular result.
Discussion with John covers two things, 1) what do the results of these tests indicate; 2) Cepstral analysis and how to recover the exact driver performance under non-ideal conditions. The first part we seem to agree that phase is varying linearly as the rings of patterns are applied, which seems to indicate a shift in acoustic center (nore clearly understood once one starts doing measurements). The second subject we really don't have any further understanding than what is written. Really trying to figure out how to get the low frequency data out of a mess of reflections in a normal room measuring environment.
I already apply the pattern yet again, step by step while doing listening in between, well.what should I say ? I does improve the sound again, comparing to untreated driver, depth and clarity is much improved, as well as ambience, detail retrieval and much reduced "spitt". This goes from top to bottom, bass is much more defined, this speaker starting to sound like much more expensive driver.
treating the whizzer cone and the dustcap is a must, I can not imagine any full range driver without this treatment, as I've tried step by step and listening in between, and see much improved clarity, again cone "rumble" is much reduced.
PS: I didn't get the printed pattern to work, somehow the size didn't fit, instead I did my best to draw the pattern(the show must go on !!
) and ending up with 14 sets of blocks instead of 18.
The only part I haven't put the pattern on is on the main cone,underneath the whizzer. Probably tommorow, this pattern improve the sound everytime I apply more of it !!
PS: Photo of the applied pattern soon.
Hartono
treating the whizzer cone and the dustcap is a must, I can not imagine any full range driver without this treatment, as I've tried step by step and listening in between, and see much improved clarity, again cone "rumble" is much reduced.
PS: I didn't get the printed pattern to work, somehow the size didn't fit, instead I did my best to draw the pattern(the show must go on !!
) and ending up with 14 sets of blocks instead of 18.The only part I haven't put the pattern on is on the main cone,underneath the whizzer. Probably tommorow, this pattern improve the sound everytime I apply more of it !!
PS: Photo of the applied pattern soon.
Hartono
Soongsc,
Your estimations about density of patterns and material hardness are in line with my experience. The first speakers I treated, a pair of Ohm F's, ended up with a very widely spaced set of rings, almost 20mm apart, and the blocks were very abbreviated, at the terminus of the first portion of the Walsh cone. This sector was made from a very hard Titanium alloy and was quite thin. Any more material or closer spacing than this caused a pretty drastic reduction in HF output.
Another format you might look into is the effect of two sided patterning on a cone. Both adjacent and what I am going to try on the next pair of Lowthers that come my way.
A normal pair of rings at start and finish of the main cone, but with the ring pair nearest the voice coil, on the back side and a slight step in position of rings, at the outer perimeter, on both sides. I will then apply a gloss coat and use tooth paste to find the proper placement for the inner ring on the front side of the main cone.
Wish I had your test set up to look at it with...
Bud
Your estimations about density of patterns and material hardness are in line with my experience. The first speakers I treated, a pair of Ohm F's, ended up with a very widely spaced set of rings, almost 20mm apart, and the blocks were very abbreviated, at the terminus of the first portion of the Walsh cone. This sector was made from a very hard Titanium alloy and was quite thin. Any more material or closer spacing than this caused a pretty drastic reduction in HF output.
Another format you might look into is the effect of two sided patterning on a cone. Both adjacent and what I am going to try on the next pair of Lowthers that come my way.
A normal pair of rings at start and finish of the main cone, but with the ring pair nearest the voice coil, on the back side and a slight step in position of rings, at the outer perimeter, on both sides. I will then apply a gloss coat and use tooth paste to find the proper placement for the inner ring on the front side of the main cone.
Wish I had your test set up to look at it with...
Bud
Hi Soongsc,
-----"No more results?"-----
I'm still thinking what to do next, do you have any suggestion ?
-----"My current investigations seem to indicate that stiffer cones may not need such dense patterns. I will be testing some different material soon."------
It seems the pattern compliance undergoes change as it dries, as well the sound.(based on my experience with acrylic paint I notice different brand looks and feel different as it dries), maybe my acrylic paint is not that good,it become brittle as it dries, I've seen others that become thicker(for lack of better words) Sakura/Tamiya brand seems to maintain it's pliability and not so brittle as it dries, I might try different brand paint later, but for now I'll stick with this one and see what can be done with the pattern itself.
Hartono
-----"No more results?"-----
I'm still thinking what to do next, do you have any suggestion ?
-----"My current investigations seem to indicate that stiffer cones may not need such dense patterns. I will be testing some different material soon."------
It seems the pattern compliance undergoes change as it dries, as well the sound.(based on my experience with acrylic paint I notice different brand looks and feel different as it dries), maybe my acrylic paint is not that good,it become brittle as it dries, I've seen others that become thicker(for lack of better words) Sakura/Tamiya brand seems to maintain it's pliability and not so brittle as it dries, I might try different brand paint later, but for now I'll stick with this one and see what can be done with the pattern itself.
Hartono
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