maxro said:
B&W dimples cones, baffles and ports
Monitor Audio dimples drivers
An externally hosted image should be here but it was not working when we last tested it.
This looks to be quite a bit different then a small microscopic layer of paint.
This is one of the most frustrating threads I have ever read! Objective and subjective data is important. To my knowledge, the Enable process was developed in an effort to calm some of the excitability in Fostex full range drivers. Many over at the full range forums love their sound but when pushed - or on certain types of music - these drivers experience some congestion and hysteria making them much less than perfect. Taking the good with the bad, many of us chose to live with this compromise because multi-way designs are even more of a compromise, having more negative issues – IMO. The Enable process was to reduce this malady in Fostex drivers and similar full range drivers experiencing the same phenomena. The spirit in which this tweak was developed was well intended, I believe. The results have been on display at many listening workshops and I have only read positive feedback from people that do not even own enabled drivers. Not to reduce what John has taken the time to do, but I think the tests maybe should have been done using the drivers intended for the tweak. I understand why John used the metal cone drivers. It makes sense. But these drivers do not perform the same as the popular full range drivers we love so much at the full range driver forums. As far as I know, the Enable process is not meant as a fix for every driver and was developed specifically for certain drivers. I can not help but conclude the tests done are meaningless unless the drivers used are ones specifically meant for the treatment. Personally, a stock vs a treated driver is the only way to properly judge how this tweak sounds or does not sound. I had to get that off my chest. Thanks,
Godzilla
PS, I do not have an Enabled driver but I know of the hysteria/congestion the tweak was meant to help fix.
Godzilla
PS, I do not have an Enabled driver but I know of the hysteria/congestion the tweak was meant to help fix.
planet10 said:
Dave, let me put it another way. The enable patches will still have an acoustic BL on them due to the passage of the waves over them. They don't rise above the BL. As per your analogy, if the enable patches are the Andes then the acoustic boundary layer is 3" of snow covering them. So the two cases are the Andes covered with 3" of snow (treated baffle) vs. the great planes covered with 3" of snow (untreated baffle). My point is that before you start worrying about what the snow does (or doesn't do), worry about what the presents of the Andes do by themselves.
The acoustic BL is a result of the propagation of an acoustic wave. It does not alter or redirect the propagation. If the acoustic BL changes it is because the wave propagation has changed, not the other way around. If enable does anything to edge diffraction is because it changes the diffraction, not because it changes the acoustic BL.
So now the problem is a standard diffraction problem. If enable applied to a baffle edge does anything it is the result of diffraction of the wave by the patterns. So next we have to ask the question how much of a disruption can this be compared to the wave propagating off the baffle edge? How much difference can it make in the diffraction at the edge? Instead of trying to explain what this would be and how it relates to turning of the acoustic wave let me make another analogy. The enable pattern is like rumble strips at the edge of a cliff compared to no rumble strips. Driving over the rumble strips may have a very small effect on how my car behaves as it approaches the edge; it will have little impact of what happens after I have driver over the edge.
This entire thread has been and continues to be filled with claims of what does and what doesn't happen and claims of that it happens because of some mystical cause/effect relationship. The problem is that in many cases the cause and effect seem to be reversed. It has been argued that we can't measure the effects. Bah! When we stick a mic out we measure exactly the same wave form we hear. If you don't believe that then we have a real impass because we are relying on those same mic to pick up the live signals of what we record in the first place.
Not to mention that with the driver cases the claim dlr was originally disputing was that enable doesn't change the FR. Yet when confronted with data that clearly shows changes in the FR, even in data posted by Bud, the response some individuals has been that these changes don't correlate with what is heard. And that what is heard is too small to be revealed in normal measurement. So what would you have me believe? That those reporting subjective differences in what they hear have hearing so acute that they can hear things that aren't revealed in the measurements, yet they can not identify or notice the 3, 4, and 5 dB variation in FR that have been shown to exist in the measurement? Maybe what they hear is very much reflected by the measurement.
.
Personally I think Dave could have mixed some dammar and silly putty and stuck it into bottles to sell rather than work so hard at figuring a pattern if he wanted to exploit us. The pattern may not be optimal from a scientific standpoint but I see cabinet designs for Lowther speakers developed prior to computer software that are very well intentioned but certainly not optimal. Maybe Dave is exploiting us? But I do not think a guy that so seriously strives for good sound using full range drivers and who is an active participant in figuring out how to improve things would crap in his own kitchen. I would bet the tweak works on the drivers he sells to some degree or another. If Enable calms the hysteria than it works. It does not cost an arm and a leg to buy and the aluminum cone test results show it certainly does something. I do not think it is a scam rather a tweak people are excited about and want to understand. Dave just branded it in order to call it something and sell it along with his flat pack speaker cabinets and phase plugs. Scan Speak has drivers that have slight score marks in them supposedly for acoustic reasons. Would these drivers sound different without the score marks? I do not know.
http://www.neeper-acoustics.com/pics/tech_bassmid.jpg
I have tried tweaks like dammar on my drivers and find they do alter the treble response. I do not feel the tweak merits changing every driver permanently. That is why I do not cut off my dustcaps or dammar all my drivers. But dammar did reduce some nasty sounds coming from cheap piezo tweeters to good effect which was proof enough for me to feel the tweak worthy on that driver. By selling the tweak Dave is offering the opportunity to own something equivalent to a Honda supped up or a Camaro with some kind of tuning package. Many feel the stock car is perfectly fine but there will always be some that want to alter performance along the lines it was meant. If a Mustang was sent in for a stiffer sport suspension tweak at an aftermarket dealer that tweak may not be appreciated by Grandpa Joe whose hemorrhoids always act up. This type of tweak tunes certain drivers and if people want to pay for the changes it produces then they should be allowed to without scrutiny. Just as the little Honda zips around town buzzing and whining like a mosquito – and the kid enjoys it – it is worthwhile to him. A fuel injection tweak that works wonders on a Honda may not work at all on a VW. To truly better understand this tweak the tests need to be redone using Fostex or other drivers meant for the tweak. Will anyone volunteer sending a pair of Fostex 126 or 127 for testing? That is if John would be willing to re do the testing?
>>> Maybe what they hear is very much reflected by the measurement.
I believe that may very well be the case.
http://www.neeper-acoustics.com/pics/tech_bassmid.jpg
I have tried tweaks like dammar on my drivers and find they do alter the treble response. I do not feel the tweak merits changing every driver permanently. That is why I do not cut off my dustcaps or dammar all my drivers. But dammar did reduce some nasty sounds coming from cheap piezo tweeters to good effect which was proof enough for me to feel the tweak worthy on that driver. By selling the tweak Dave is offering the opportunity to own something equivalent to a Honda supped up or a Camaro with some kind of tuning package. Many feel the stock car is perfectly fine but there will always be some that want to alter performance along the lines it was meant. If a Mustang was sent in for a stiffer sport suspension tweak at an aftermarket dealer that tweak may not be appreciated by Grandpa Joe whose hemorrhoids always act up. This type of tweak tunes certain drivers and if people want to pay for the changes it produces then they should be allowed to without scrutiny. Just as the little Honda zips around town buzzing and whining like a mosquito – and the kid enjoys it – it is worthwhile to him. A fuel injection tweak that works wonders on a Honda may not work at all on a VW. To truly better understand this tweak the tests need to be redone using Fostex or other drivers meant for the tweak. Will anyone volunteer sending a pair of Fostex 126 or 127 for testing? That is if John would be willing to re do the testing?
>>> Maybe what they hear is very much reflected by the measurement.
I believe that may very well be the case.
john k... said:
Not to be too picky, but are you intimating that all microphones are the same (as far as information retrieval goes, and not directionality, etc.)? Can an $80 Behringer mike retrieve the same amount of information as a $1200 Schoeps or AKG, and are the recording engineers that swear by them audiophool jewelry collectors?
Magnetar said:
Take it for granted that I have only been reading on this topic for a couple of weeks now and have seen this stated in the thread already but if this was the case it wouldn't be offered to the DIY community. It just that plain and simple to me. If it was the case it would be a big secret with a bunch of mumbo jumbo or how it was the best thing in the world on the website of the person marketing and selling this. Kinda like the stuff that markets "as seen on TV" items.
All the measurements are great but what works for me is does it sound better (not just differant) to my ears. If in doubt try it for yourself to the drivers that this process is said to have made improvements on then go from there. This is what I plan to do, if I don't like it than it's no big deal since the Fe127 is a cheap enough driver to replace. If anything you gain the artistic knowledge of how to use differant calligraphy tips
.I am grateful that there are people like Dave, Bud, Chris etc. that are willing to share this to all and go more than out of there way to helps others out. True class in my eyes.
magnetar,
Now now, that is only microscopic in your mind.
As John K has shown, the EnABL blocks are huge when compared to the area where the transverse wave, in the diaphragm, creates the longitudinal compression/ rarification wave, in adjacent air, through the boundary layer, as the wave traverses the diaphragm.
This is essentially a still air zone boundary layer, with a compression wave leading edge traveling across it. This type of boundary layer can be quite thick, when compared to a laminar flow zone with a "wind" crossing it. In addition, the transverse energy wave, originally created by the voice coil true piston, as a shear wave in the diaphragm, remains in the diaphragm.
It is just the transform point that is expressed in and through the boundary layer. Some disputed tests and models show that EnABL is ensuring this thickened boundary layer, in still air, and causing the point of transform to move away from the diaphragm far enough, that it does not allow the energy to reenter the diaphragm, as it would otherwise do.
When we get to the baffle, the energy from the leading edge of the expanding compression wave, actually produces a transverse wave through the boundary layer and into the baffle material, to a degree determined by the density and flexibility of that baffle material. This is also a still air boundary layer. Unless the EnABL pattern once again controls this transform point distance from the baffle.
In the presentation I provided earlier on baffle diffraction and reflection reduction, I did not point out strongly that the energy that wraps around the baffle and traverses the box side, continues to do this. The energy that leaves the baffle at a congruent angle to the pressure wave, in 2 pi expansion vector, continues to do so.
All that does not appear to continue happening is the lobe emissions out into the original 2 pi space, that is now 4 pi. I have never actually listened for lobe emission from the sides of the box, angling back into the new 4 pi volume, but from directly to the sides, no lobing is apparent. There is a pretty good increase in information dynamics, as you move forward, past the front baffle edge, but not any changes that seem to indicate lobes being deployed.
godzilla,
Dave is correct. This was originally designed to terminate a bending wave transducer, one where the bulk of the energy transform, from diaphragm to air, is through a transverse wave to compression wave transform point, through a boundary layer.
Dale Harder, the current manufacturer of the Walsh drivers, originally known as Ohm F's, says that the measured wave speed, as an average, exceeds 6k ft per second, as a transverse waveform down the cone.
These drivers have terrible piston action, with bass production not really equivalent to a piston based woofer, though both are bending wave transducers for most of their frequency response.
I was quite surprised when I discovered that the EnABL process worked on "piston" drivers, as effectively as it does on the Walsh drivers. Results were the same as far as information density was concerned. And neither case showed enough alteration in characteristics, to warrant a claim of "improving" the tone. Although, as John Ver Halen pointed out, the leading and trailing edge transients were notable in their completeness, when compared to an untreated driver.
That the process also works, as well as it does on full range drivers just closes the circle for me. All drivers are able to work as transverse wave emitters, when properly terminated. They also work as pistons, but actually seem to work a bit better, than a driver that is not also working properly, as a transmission line bending wave emitter.
The information content increase is the real beneficiary here, and of course, so are we.
Still lots of arguments to be had. We will work out the actual mode of operation as time goes on. I am sure it will surprise all of us.
Bud
Now now, that is only microscopic in your mind.
As John K has shown, the EnABL blocks are huge when compared to the area where the transverse wave, in the diaphragm, creates the longitudinal compression/ rarification wave, in adjacent air, through the boundary layer, as the wave traverses the diaphragm.
This is essentially a still air zone boundary layer, with a compression wave leading edge traveling across it. This type of boundary layer can be quite thick, when compared to a laminar flow zone with a "wind" crossing it. In addition, the transverse energy wave, originally created by the voice coil true piston, as a shear wave in the diaphragm, remains in the diaphragm.
It is just the transform point that is expressed in and through the boundary layer. Some disputed tests and models show that EnABL is ensuring this thickened boundary layer, in still air, and causing the point of transform to move away from the diaphragm far enough, that it does not allow the energy to reenter the diaphragm, as it would otherwise do.
When we get to the baffle, the energy from the leading edge of the expanding compression wave, actually produces a transverse wave through the boundary layer and into the baffle material, to a degree determined by the density and flexibility of that baffle material. This is also a still air boundary layer. Unless the EnABL pattern once again controls this transform point distance from the baffle.
In the presentation I provided earlier on baffle diffraction and reflection reduction, I did not point out strongly that the energy that wraps around the baffle and traverses the box side, continues to do this. The energy that leaves the baffle at a congruent angle to the pressure wave, in 2 pi expansion vector, continues to do so.
All that does not appear to continue happening is the lobe emissions out into the original 2 pi space, that is now 4 pi. I have never actually listened for lobe emission from the sides of the box, angling back into the new 4 pi volume, but from directly to the sides, no lobing is apparent. There is a pretty good increase in information dynamics, as you move forward, past the front baffle edge, but not any changes that seem to indicate lobes being deployed.
godzilla,
Dave is correct. This was originally designed to terminate a bending wave transducer, one where the bulk of the energy transform, from diaphragm to air, is through a transverse wave to compression wave transform point, through a boundary layer.
Dale Harder, the current manufacturer of the Walsh drivers, originally known as Ohm F's, says that the measured wave speed, as an average, exceeds 6k ft per second, as a transverse waveform down the cone.
These drivers have terrible piston action, with bass production not really equivalent to a piston based woofer, though both are bending wave transducers for most of their frequency response.
I was quite surprised when I discovered that the EnABL process worked on "piston" drivers, as effectively as it does on the Walsh drivers. Results were the same as far as information density was concerned. And neither case showed enough alteration in characteristics, to warrant a claim of "improving" the tone. Although, as John Ver Halen pointed out, the leading and trailing edge transients were notable in their completeness, when compared to an untreated driver.
That the process also works, as well as it does on full range drivers just closes the circle for me. All drivers are able to work as transverse wave emitters, when properly terminated. They also work as pistons, but actually seem to work a bit better, than a driver that is not also working properly, as a transmission line bending wave emitter.
The information content increase is the real beneficiary here, and of course, so are we.
Still lots of arguments to be had. We will work out the actual mode of operation as time goes on. I am sure it will surprise all of us.
Bud
Dimpling ports and baffles is for the purpose of "spreading out" the impedance boundary, is it not? Spread it out and the diffraction takes place over larger distance and therefore longer period. Same energy dispersion over longer time means lower diffraction SPL at any given moment. Hopefully, inaudible SPL.
I do not think it matters whether the spreading mechanism is bumps or dimples. Instead of dimples, you could have holes, even.
If a paint bump is high enough it should work for some range of frequencies.
The dimples in the speaker cone could be for structural purpose - stiffening the structure - or for acoustic reasons - dampening the waves traveling through the diaphragm material - or both.
And the dimples do look kind of NEAT, right?
I do not think those dimples we see on those pictures have a thing to do with BL phenomena like on a golf ball.
I do not think it matters whether the spreading mechanism is bumps or dimples. Instead of dimples, you could have holes, even.
If a paint bump is high enough it should work for some range of frequencies.
The dimples in the speaker cone could be for structural purpose - stiffening the structure - or for acoustic reasons - dampening the waves traveling through the diaphragm material - or both.
And the dimples do look kind of NEAT, right?
I do not think those dimples we see on those pictures have a thing to do with BL phenomena like on a golf ball.
An externally hosted image should be here but it was not working when we last tested it.
John K,
Thanks John, it is still very cool.
May I have copies of the original plots? I will not release them into info space, without your specific approval. I just want to look much further into the comparative aspects you have already shown. Please PM me if you are willing and I will provide my email address. If you aren't comfortable providing the fruits of your labor, that's perfectly understandable too.
Bud
Thanks John, it is still very cool.
May I have copies of the original plots? I will not release them into info space, without your specific approval. I just want to look much further into the comparative aspects you have already shown. Please PM me if you are willing and I will provide my email address. If you aren't comfortable providing the fruits of your labor, that's perfectly understandable too.
Bud
john k... said:
A better analogy would be a tsunami crashing into the mountains... If Bud's numbers and yours are correct the water would be 3" deep and the montains 17" high.
I think we can more accurately say that the waveform that passes thru the same space is the same. The way that the head and the way that a mic distort that waveform on the other hand are significantly different and what the microphone captures is at best a crude facsimile of what the ear is capturing. Further, there is no computer in the world that had the million+ years of evolutionary tuning that allows it to analyze the impinging waveform as well as the human brain.
dave
Are yall still tossing this one back and forth? Amazing!
Sorry , its still nothing more than an energy front travelling over a surface which imparts energy to the surface which collides with later produced energy travelling over the surface. This provides cancellation/re-enforcement of the energy which is again imparted into the cone surface according to the phase/time/distance/energy and frequency.
Its simple.
ron
my mentor ,friend,prof and a genius " the hardest thing you can do is to make something simple"
Sorry , its still nothing more than an energy front travelling over a surface which imparts energy to the surface which collides with later produced energy travelling over the surface. This provides cancellation/re-enforcement of the energy which is again imparted into the cone surface according to the phase/time/distance/energy and frequency.
Its simple.
ron
my mentor ,friend,prof and a genius " the hardest thing you can do is to make something simple"
BudP said:
It's only February, but I nominate this for "Techno-babble post of the year award". Thanks Bud, that was great. Bravo, bravo.
Now, if EnaBling reduces diffraction, wouldn't it make sense to apply some to the forehead, pinna and torso to affect HRTF as well?
You know diffraction is quite measurable? But perhaps, as previously, the measured data would be useless in explaining the what is really taking place? Are you open minded enough to consider that the answer may not lie in the soundwave, so measurements of that are futile?
cheers,
AJ
Wow, finally, A contender!
whuzzat?
Actually I am open to it being a result of the "Head On" commercials.
In your mysteriously disappearing post, I was referring to how many AJ monkeys there are, in just this thread, not to mention in the rest of this forum, doing some mysterious activity. I was hoping it applied to typing and creating great works of babble art. I thought it seemed a reasonable assumption, given the posts.Bud
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