Cal Weldon said:
Yes, then there's that funky Fostex Sigma surround - if that can be impressed in what appears to be treated fabric, then embossing something like the EnABL pattern in the cone themselves should be relatively straightforward.
Of course the embossing begs the question of researching of laminated cone structures with appropriate materials to preclude the application of the gloss coats.
All that this Thought Engine co-operative needs is unlimited resources of time and technology, and the willingness to step outside the box.
I think you have pointed out the most important audible differences. Drivers show it's own sonic signature when residual resonances remain strong.LAL said:
The last time I used the word "Federation" was actually during a presentation on simulation training.🙂 But it seems that a few neat ideas have come up from individuals, it seemed like a good idea to push forward as a team.BudP said:
If you paint something on a diaphragm and it changes the radiation characteristics, then the change is due either to added mass, or extended layer damping or, if both sides are coated, constrained layer damping. Or both.
http://www.scientific.net/Analysis+of+Free-Layer+Damping+Coatings.html
A diaphragm is a skinny beam with relatively huge surface area available for coating.
Acrylic resin used in paint adheres well, and I expect is relatively stiff compared to treated paper. I had trouble digging up material properties for acrylic resins used in paint.
I suspect the pigments added to the paint probably confer added stiffness to the coating as they are included in the polymer structure in some fashion and they add mass.
Damping material doesn't have to be applied uniformly across the beam surface but can be applied in critical areas - the case of a diaphragm, near boundaries (high energy area), but not at the boundaries (low energy area). In the case of the enABL pattern this is what is done.
The enABL pattern is interesting in that it resembles what is done with the damping patches seen here in figure 4
http://www.sdtools.com/pdf/isma04_prospadd.pdf
The discontinuities between the enABL patches allow for a large number of overlapping "impedance boundary" energy losses and/or disallow the breakup or extreme deformation of the coating or even extreme deformation of coating-diaphragm combination.
Found it! annular membrane!
http://www.google.com/search?as_q=&...as_dt=i&as_sitesearch=&as_rights=&safe=images
Now, if I want to read anything about the subject, I'm going to have to pony up some serious money. Who is paying $50 to look at a single article?
http://www.scientific.net/Analysis+of+Free-Layer+Damping+Coatings.html
A diaphragm is a skinny beam with relatively huge surface area available for coating.
Acrylic resin used in paint adheres well, and I expect is relatively stiff compared to treated paper. I had trouble digging up material properties for acrylic resins used in paint.
I suspect the pigments added to the paint probably confer added stiffness to the coating as they are included in the polymer structure in some fashion and they add mass.
Damping material doesn't have to be applied uniformly across the beam surface but can be applied in critical areas - the case of a diaphragm, near boundaries (high energy area), but not at the boundaries (low energy area). In the case of the enABL pattern this is what is done.
The enABL pattern is interesting in that it resembles what is done with the damping patches seen here in figure 4
http://www.sdtools.com/pdf/isma04_prospadd.pdf
The discontinuities between the enABL patches allow for a large number of overlapping "impedance boundary" energy losses and/or disallow the breakup or extreme deformation of the coating or even extreme deformation of coating-diaphragm combination.
Found it! annular membrane!
http://www.google.com/search?as_q=&...as_dt=i&as_sitesearch=&as_rights=&safe=images
Now, if I want to read anything about the subject, I'm going to have to pony up some serious money. Who is paying $50 to look at a single article?
Hi Frank,
Now that was a seriously helpful post. If you think that the annular membrane paper will further the look into the physical energy transform you have already spoken of, I will buy the paper.
Bud
Now that was a seriously helpful post. If you think that the annular membrane paper will further the look into the physical energy transform you have already spoken of, I will buy the paper.
Bud
SY said:
If you find him, tell him I want Jessica Alba and 2 JBL2269G's for christmas.
SY said:
Whoa. I'm not questioning the audibility of added mass/stiffness to a crappy cone, having done so myself. It's the Radioshack turned Excel sound from the treatment, baffle/horn improvement, increased dynamics, etc. down the rabbit hole stuff that has me skeptically tickled. The one treatment cures all cones and cancer type stuff instead of MarkMcK specific per cone/measurements.
BTW, take a look at this EnaBLed drivers measurements. Do you know what stands out to me? The change in FR? The CSD? The almost obscene fuzzy ring thing? No. It's how anyone can be gushing about "absolutely amazing" improvements to such a god awful sounding speaker. (But you haven't heard/experienced it yourself - yeah, I know...thank goodness 😉)
An externally hosted image should be here but it was not working when we last tested it.
I'm sorry, but my ears would not be as forgiving (mental block?) of anything that horrific. Maybe a Bose cube owner, but not I.
No. I'm pointing out that everyone trusts their ears, including the ghost, magic pebbles, frozen photos hearing folks.jlsem said:
All human, subject to biases, expectations, etc. just like you and me.
FrankWW. You got it. Except that might not be as mysterious and mystical as some would like it.
That each different cone with it's unique modes and characteristics would have to be treated differently after measurements (per MarkMcK, Scan Speak, Vifa NRSC, etc.) almost seems lost here.
cheers,
AJ
Hi,
seems I'm the next one to give this interesting stuff a try, having read this monster thread on an off... got some el-cheap-o boxes with 4 mid-woofers in total, enough material to try and compare. Really nasty stuff, polyprop of the cheapest variety with enough breakup to be healed... I'm listening to one of the raw drives in this moment, to get used to the "before" sound -- enjoying that infamous sans baffle dipole sound, effortless bass, nevertheless.
I have to say I'm EE and have some scientific background, but I'm in no way biased. I hope to get my measurement mic/pre fixed and plan to do some in-depth measurements. I recently learned about the Earl Geddes method of time-domain averaging before FFTing in synced measurements (works with single tone and multi tone, shaped bursts etc) which gives a big increase in resolution and excellent noise suppression, also any components which aren't exact FFT bin frequencies cancel out. Which might pose a problem: mechanical harmonics sometimes arent exact multiples of the fundamental because of nonlinearities involved (I know this from the spread in harmonics of plucked guitar strings, e.g.). Is this a known issue with speaker breakup modes?
- Klaus
seems I'm the next one to give this interesting stuff a try, having read this monster thread on an off... got some el-cheap-o boxes with 4 mid-woofers in total, enough material to try and compare. Really nasty stuff, polyprop of the cheapest variety with enough breakup to be healed... I'm listening to one of the raw drives in this moment, to get used to the "before" sound -- enjoying that infamous sans baffle dipole sound, effortless bass, nevertheless.
I have to say I'm EE and have some scientific background, but I'm in no way biased. I hope to get my measurement mic/pre fixed and plan to do some in-depth measurements. I recently learned about the Earl Geddes method of time-domain averaging before FFTing in synced measurements (works with single tone and multi tone, shaped bursts etc) which gives a big increase in resolution and excellent noise suppression, also any components which aren't exact FFT bin frequencies cancel out. Which might pose a problem: mechanical harmonics sometimes arent exact multiples of the fundamental because of nonlinearities involved (I know this from the spread in harmonics of plucked guitar strings, e.g.). Is this a known issue with speaker breakup modes?
- Klaus
AJinFLA said:
I guess I should just add this to your ramblings in Lynn's thread from last night...
Klaus,
The few polyprop cones I have treated have always needed "tooth" added to their surfaces, for the acrylic to adhere to strongly. Probably ok for just fooling around, but the gloss coat will lift after a period of time. I use #2000 grit or finer, so not very much "tooth" is needed.
AJ,
You are correct, in that every cone, dome, planar, requires it's own particular treatment. The EnABL patterns are usually near the boundary edges, but not on them. Every driver I treat is looked at as an individual case, but with experienced eyes. The part of EnABL that changes the most, other than the pattern blocks and ring sizes growing or shrinking, is the amount of conformal coating that any particular driver requires. Since I have not found which of the myriad of tests I need to use, to determine this before application, I apply it sparingly, over a lengthy period of time and just let the driver response to music, guide the conformal coating process. I do hope this scandalizes you ! I enjoy your responses.
As for RAAL ribbons, I wouldn't think I need to touch one. Having discussed what Alexsander is doing with his ribbons, with him, I doubt that they need help from EnABL. He is interested in looking at using it in his resonance chambers, but it is not a high priority for him, or me.
What speaker is the FR plot from? I would like to see a higher resolution picture and know something more about the test conditions involved. Can you help with this, or provide a link?
Bud
The few polyprop cones I have treated have always needed "tooth" added to their surfaces, for the acrylic to adhere to strongly. Probably ok for just fooling around, but the gloss coat will lift after a period of time. I use #2000 grit or finer, so not very much "tooth" is needed.
AJ,
You are correct, in that every cone, dome, planar, requires it's own particular treatment. The EnABL patterns are usually near the boundary edges, but not on them. Every driver I treat is looked at as an individual case, but with experienced eyes. The part of EnABL that changes the most, other than the pattern blocks and ring sizes growing or shrinking, is the amount of conformal coating that any particular driver requires. Since I have not found which of the myriad of tests I need to use, to determine this before application, I apply it sparingly, over a lengthy period of time and just let the driver response to music, guide the conformal coating process. I do hope this scandalizes you ! I enjoy your responses.
As for RAAL ribbons, I wouldn't think I need to touch one. Having discussed what Alexsander is doing with his ribbons, with him, I doubt that they need help from EnABL. He is interested in looking at using it in his resonance chambers, but it is not a high priority for him, or me.
What speaker is the FR plot from? I would like to see a higher resolution picture and know something more about the test conditions involved. Can you help with this, or provide a link?
Bud
@Dave:
look here:
Geddes on distortion measurements.
Only "problem" is you need to write your own little piece of software for it, or wait until mine is ready for publishing. The core is actually extremely simple, though. The work is in the .WAV- and user-interface, if you use plain C or C++. The Python language has some nice features to make this not a problem, as far as I know.
@Bud:
Thanks for the remarks on polyprop. I thought of using nail polish which contains acetone and might combine nicely with the material (or completely dissolve it
)... but I better stick to sanding paper, or steel wool, I think...
The link in question is just above the plot, in the "EnABLed"
Klaus
look here:
Geddes on distortion measurements.
Only "problem" is you need to write your own little piece of software for it, or wait until mine is ready for publishing. The core is actually extremely simple, though. The work is in the .WAV- and user-interface, if you use plain C or C++. The Python language has some nice features to make this not a problem, as far as I know.
@Bud:
Thanks for the remarks on polyprop. I thought of using nail polish which contains acetone and might combine nicely with the material (or completely dissolve it
)... but I better stick to sanding paper, or steel wool, I think...The link in question is just above the plot, in the "EnABLed"
Klaus
Has anyone proposed or done this goofy experiment?
Materials:
old speaker that's seen better days
Toilet paper or paper towel cardboard roll
Piece of reasonably stiff construction paper comparable to speaker diaphragm stuff that won't sag when placed across the speaker.
Cut a hole in the center of the paper the diameter of the roll
Glue one end of the roll to the dust cap or whatever's at the apex of the cone.
Slide the paper over the roll and glue its edges to the surround.
Glue roll to paper.
Cut holes in speaker diaphragm
Attach speaker to amp, signal to amp, sprinkle some salt, couscous, flour, whatever, on the paper, fire it up, take pictures or videos of patterns at replicable levels and signals. Nice, unambiguous, easily recognizable, stable patterns would be helpful.
Paint the the enable pattern on the paper in the advised fashion with advised materials, etc.
Fire it up again. Repeat procedure with same settings.
Compare the pictures/video. See if the patterns have diminished or disappeared or become less complex than before. Or not.
Ain't quantitative but is empirical.
Materials:
old speaker that's seen better days
Toilet paper or paper towel cardboard roll
Piece of reasonably stiff construction paper comparable to speaker diaphragm stuff that won't sag when placed across the speaker.
Cut a hole in the center of the paper the diameter of the roll
Glue one end of the roll to the dust cap or whatever's at the apex of the cone.
Slide the paper over the roll and glue its edges to the surround.
Glue roll to paper.
Cut holes in speaker diaphragm
Attach speaker to amp, signal to amp, sprinkle some salt, couscous, flour, whatever, on the paper, fire it up, take pictures or videos of patterns at replicable levels and signals. Nice, unambiguous, easily recognizable, stable patterns would be helpful.
Paint the the enable pattern on the paper in the advised fashion with advised materials, etc.
Fire it up again. Repeat procedure with same settings.
Compare the pictures/video. See if the patterns have diminished or disappeared or become less complex than before. Or not.
Ain't quantitative but is empirical.
KSTR said:@Dave:
look here:
Geddes on distortion measurements.
Only "problem" is you need to write your own little piece of software for it, or wait until mine is ready for publishing. The core is actually extremely simple, though. The work is in the .WAV- and user-interface, if you use plain C or C++. The Python language has some nice features to make this not a problem, as far as I know.
@Bud:
Thanks for the remarks on polyprop. I thought of using nail polish which contains acetone and might combine nicely with the material (or completely dissolve it
The link in question is just above the plot, in the "EnABLed"
Klaus
Klaus - I think I'd avoid using steel wool anywhere near a speaker. When those little whiskers of steel inevitably break off - well magnets and all..... The resulting debris could be more of a pain to remove than abrading the surface of the polyprop with superfine sandpaper per Bud's suggestion.
Chris,
you have reason, of course. In this special case the danger is quite low, though, the driver is really all closed, no VC ventilation of any kind. Still it not a good idea at any rate, so I'm using sandpaper.
Meanwhile im preparing impedance plot measurements with "constant power" drive.
btw, I disagree with the statement by someone (JohnK?) that on axis we will see everything. At the mic position it is possible (not very likely, but possible) that certain breakup modes, testing with single sines, will cancel in the acustic sum.
These more to write on that, but I have to leave, about to meet some friends and have a beer.
- Klaus
you have reason, of course. In this special case the danger is quite low, though, the driver is really all closed, no VC ventilation of any kind. Still it not a good idea at any rate, so I'm using sandpaper.
Meanwhile im preparing impedance plot measurements with "constant power" drive.
btw, I disagree with the statement by someone (JohnK?) that on axis we will see everything. At the mic position it is possible (not very likely, but possible) that certain breakup modes, testing with single sines, will cancel in the acustic sum.
These more to write on that, but I have to leave, about to meet some friends and have a beer.
- Klaus
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