Carlp said:
The problem is that the testing of drivers has shown a difference, one that I would have expected, just not to the mechanism ascribed. One big caveat I saw early on is that any reasonable person would never, ever say about any tweak that "All speakers are the best for EnABL use. The process does NOT alter the speakers inherent qualities." (see page one in the thread). This has significant implications. Those intrigued just might tweak a perfectly good driver to its detriment. Believers largely promote the tweak with absolutely no reservations. I have a serious problem with that.
Oh, without doubt. It can work both ways. All the more reason for real, verifiable double-blind tests for perceptions and thorough, properly conducted measurements to try to make a correlation.
But you, I and a few others here know that this is not a simple undertaking.
As far as my testing, I still see no purpose. I know that the driver FR of a driver is altered and that ports and baffles will not be affected but to some miniscule degree, so I've no need. All that my tests would show is that the FR is indeed altered (we know that already) and that there is no change made to ports and baffles, a negative, unprovable. And since I'm not yet into doing distortion tests, changes in that profile as well as that of mechanism of a driver has yet to be made at all. This should Bud's bailiwick.
Dave
Re: Re: Re: Re: Re: Re: Philips DVD Home Theater System HTS3455
G'day Alan,
The fundamental question is whether or not EnABL on a baffle or port makes an audible difference.
Do you still have those bread bin temp enclosures?
Try this:
1. Listen to them in stereo untreated.
2. Then EnABL the 'baffle' of one of these, then listen to them in stereo.
3. Tell us what you hear.
Then by all means go crazy with the blind A - B tests.
Cheers,
Alex
G'day Alan,
The fundamental question is whether or not EnABL on a baffle or port makes an audible difference.
Do you still have those bread bin temp enclosures?
Try this:
1. Listen to them in stereo untreated.
2. Then EnABL the 'baffle' of one of these, then listen to them in stereo.
3. Tell us what you hear.
Then by all means go crazy with the blind A - B tests.
Cheers,
Alex
John K,
What I brought to the topic of conversation was that, as the piston moved and pulled the diaphragm, a shear wave was introduced into the diaphragm that expanded into the diaphragm. The area just adjacent to the voice coil produced the beginnings of a compression wave in the adjacent air, but that the area was too small to be any more than the initiator of the wave. The shear wave stretched out in the diaphragm as a transverse wave and as the pressure peak of the wave moved across the cone surface, a continuation of the compression wave, started at the voice coil, arose from the cone surface. That the transverse wave was moving faster than the compression wave being created and expanding into the adjacent air.
As the pressure point of the transverse wave moved and poured energy into the adjacent air, with a hemispherical shape to the energy transform, the entire compression wave from voice coil to surround was created, not by the originally expanding pressure from the voice coil movement only. That his transverse wave, upon hitting the cone edge and surround was depleted, but still strong enough to enter basket and adjacent baffle, if there was one attached, and that it was still a transverse wave. That part of that energy would have been reflected back down the cone and due to it's reduced energy would not likely travel as a transverse wave utilizing the entire cone thickness. Other portions of the energy would refract and also become circulating waves.
The EnABL pattern (not called that at the time) appeared to provide enough of a correct and unknown impedance, to allow the forming compression wave to form with much less time smear and also appeared to severely reduce the amount of energy re traversing the diaphragm and forming standing waves and also corrupting both the diaphragm materials natural decay of stored energy into the air, and emission of following waves. That the pattern seemed to provide a quiescent zone where the compression wave could constitute, with the least amount of energy being lost to misalignment of the energy from the voice coil, with that contributed by the transverse wave.
That the pattern also appeared to eliminate the circulating waves and disallow refraction and reflection at the cone edge, regardless of where the surround was placed, front or back side.
Ned said that this sounded very much like a still air boundary layer. One common in energy transform from widely disparate material structures
I went on to describe the odd wave tank results and that my reading had informed me that a soliton wave has a rolling structure within the wave, that was much more pronounced than what was to be found in ordinary waves.
Ned said that it made sense for the EnABL pattern, at the voice coil, to be aiding in constructing the energy transform process and that it looked even more like an event that would be occurring in a boundary layer, primarily in the receiver medium and that it would move with the transverse wave, as an energy differential creating a surface turbulence something like weather systems do.
I mentioned that I hadn't a clue what a boundary layer was, at which point he gave me a thumbnail view of them as being an energy transformation zone from one carrier medium to another. That this was a distorted view of them but a useful understanding. I asked him what the soliton structure to the wave front would mean past the driver, where the transverse wave was no longer the force creating a compression wave.
Ned said he would have to do the math to see just how much energy the transverse wave, now in the baffle could be providing, but that he thought it would be substantial and that if I supported the event with further EnABL patterns out at the baffle edge then the same events should take place as occurred at the cone edge
I asked him if this meant that the transverse wave was still moving faster than the compression wave and he said that I was misunderstanding the event. The transverse wave was creating a compression wave at the speed of the transverse wave pressure point movement across the material it was embedded within and that the speed of sound through air was unrelated to this event, that only the speed of the wave through the various mediums was of importance.
I mentioned that a thin coating of acrylic aided the whole thing and he said that just reinforced his thought that a boundary layer event was at work, primarily because the acrylic would allow energy to transform into the air with less loss and likely would aid in a more coherent compression wave occurring.
He then offered to do the math and wanted to know if I could provide him with test data. I never found out what test data, because Mile' interrupted the conversation and forbade Ned from participating, for the reasons I have already covered.
That evening I applied a set of patterns to the edge of my personal system and found that the characteristic time coherence and lack of masking of very low level signals now extended across the baffle and that the heretofore mildly obnoxious off angle combs arising from the baffle edge had fallen to so low a level that I could no longer be sure they were there at all.
Now, due to my mental state at the time and the still turbulent memory structures from tegretol, I have had to structure this description in a specific way and the sequence of events might not have been exactly as I have portrayed. But, the impact of Ned's words is still very clear in my memory and the visual portions are still attached to the points he made. Meaning I can still see him and his gestures as he made his assumptions known. I am sure he had more to say on the subject, but I would be inventing information I could just as easily have obtained elsewhere, later.
They were just assumptions, but they made sense out of many things I had thought about and visualized, as I had treated drivers over the time prior to this discussion. So, I adopted what he had said and used that understanding to refine what I do with the EnABL patterns, successfully.
Bud
What I brought to the topic of conversation was that, as the piston moved and pulled the diaphragm, a shear wave was introduced into the diaphragm that expanded into the diaphragm. The area just adjacent to the voice coil produced the beginnings of a compression wave in the adjacent air, but that the area was too small to be any more than the initiator of the wave. The shear wave stretched out in the diaphragm as a transverse wave and as the pressure peak of the wave moved across the cone surface, a continuation of the compression wave, started at the voice coil, arose from the cone surface. That the transverse wave was moving faster than the compression wave being created and expanding into the adjacent air.
As the pressure point of the transverse wave moved and poured energy into the adjacent air, with a hemispherical shape to the energy transform, the entire compression wave from voice coil to surround was created, not by the originally expanding pressure from the voice coil movement only. That his transverse wave, upon hitting the cone edge and surround was depleted, but still strong enough to enter basket and adjacent baffle, if there was one attached, and that it was still a transverse wave. That part of that energy would have been reflected back down the cone and due to it's reduced energy would not likely travel as a transverse wave utilizing the entire cone thickness. Other portions of the energy would refract and also become circulating waves.
The EnABL pattern (not called that at the time) appeared to provide enough of a correct and unknown impedance, to allow the forming compression wave to form with much less time smear and also appeared to severely reduce the amount of energy re traversing the diaphragm and forming standing waves and also corrupting both the diaphragm materials natural decay of stored energy into the air, and emission of following waves. That the pattern seemed to provide a quiescent zone where the compression wave could constitute, with the least amount of energy being lost to misalignment of the energy from the voice coil, with that contributed by the transverse wave.
That the pattern also appeared to eliminate the circulating waves and disallow refraction and reflection at the cone edge, regardless of where the surround was placed, front or back side.
Ned said that this sounded very much like a still air boundary layer. One common in energy transform from widely disparate material structures
I went on to describe the odd wave tank results and that my reading had informed me that a soliton wave has a rolling structure within the wave, that was much more pronounced than what was to be found in ordinary waves.
Ned said that it made sense for the EnABL pattern, at the voice coil, to be aiding in constructing the energy transform process and that it looked even more like an event that would be occurring in a boundary layer, primarily in the receiver medium and that it would move with the transverse wave, as an energy differential creating a surface turbulence something like weather systems do.
I mentioned that I hadn't a clue what a boundary layer was, at which point he gave me a thumbnail view of them as being an energy transformation zone from one carrier medium to another. That this was a distorted view of them but a useful understanding. I asked him what the soliton structure to the wave front would mean past the driver, where the transverse wave was no longer the force creating a compression wave.
Ned said he would have to do the math to see just how much energy the transverse wave, now in the baffle could be providing, but that he thought it would be substantial and that if I supported the event with further EnABL patterns out at the baffle edge then the same events should take place as occurred at the cone edge
I asked him if this meant that the transverse wave was still moving faster than the compression wave and he said that I was misunderstanding the event. The transverse wave was creating a compression wave at the speed of the transverse wave pressure point movement across the material it was embedded within and that the speed of sound through air was unrelated to this event, that only the speed of the wave through the various mediums was of importance.
I mentioned that a thin coating of acrylic aided the whole thing and he said that just reinforced his thought that a boundary layer event was at work, primarily because the acrylic would allow energy to transform into the air with less loss and likely would aid in a more coherent compression wave occurring.
He then offered to do the math and wanted to know if I could provide him with test data. I never found out what test data, because Mile' interrupted the conversation and forbade Ned from participating, for the reasons I have already covered.
That evening I applied a set of patterns to the edge of my personal system and found that the characteristic time coherence and lack of masking of very low level signals now extended across the baffle and that the heretofore mildly obnoxious off angle combs arising from the baffle edge had fallen to so low a level that I could no longer be sure they were there at all.
Now, due to my mental state at the time and the still turbulent memory structures from tegretol, I have had to structure this description in a specific way and the sequence of events might not have been exactly as I have portrayed. But, the impact of Ned's words is still very clear in my memory and the visual portions are still attached to the points he made. Meaning I can still see him and his gestures as he made his assumptions known. I am sure he had more to say on the subject, but I would be inventing information I could just as easily have obtained elsewhere, later.
They were just assumptions, but they made sense out of many things I had thought about and visualized, as I had treated drivers over the time prior to this discussion. So, I adopted what he had said and used that understanding to refine what I do with the EnABL patterns, successfully.
Bud
BTW, re: my rhetorical question re: placebo effect on disbelievers, I knew the answer before posing the question.
Huh? Goldplater, methinks you misread my post. Faulty logic?
Dave, you're right, I do understand it's no small undertaking to really study the full issue here, so I didn't really expect you or anyone else to take that on, much as I'd like to. I wish I had the ability and equipment to do the testing as I'd sure try. I just want you and others to know that not everyone takes this or any other thread on it's face value. (of course, that doesn't also mean we don't believe in the possibilities either....).
Finally, re: distortion tests, I've been wondering if here is a nut to be cracked...
Carl
Huh? Goldplater, methinks you misread my post. Faulty logic?
Dave, you're right, I do understand it's no small undertaking to really study the full issue here, so I didn't really expect you or anyone else to take that on, much as I'd like to. I wish I had the ability and equipment to do the testing as I'd sure try. I just want you and others to know that not everyone takes this or any other thread on it's face value. (of course, that doesn't also mean we don't believe in the possibilities either....).
Finally, re: distortion tests, I've been wondering if here is a nut to be cracked...
Carl
It may be that early on claims were made that all speaks would benefit from EnABL (I haven't been able to carefully read the early portion of the thread, and it was so far back it seems only relevant re: the development of ideas here). But even Bud has been clear in the last few pages of this thread that not every speaker will benefit from it. Your warning about treating perfectly good speaks is well taken, but I do wonder, now that some time and "testing" has passed, if there is a potential for damaging sound quality with EnABL. I don't have the $$ to treat anything but el cheapo drivers so it won't affect me, but I'm still curious. Anyone care to weight in on that question?
Carl
Re: Re: Re: Re: Re: Re: Re: Philips DVD Home Theater System HTS3455
OK - there's no room on the baffle for EnABL round the driver bit - the driver goes too close to the edge, but I could EnABL round the outside. Do you think that would be as effective?
You can see that from the pics:
However, I know the sound of these speakers now, I've listened to them a LOT - and they would be easier to A/B because they don't weight 1 tonne each like the Sachikos will!
Alans Pics
Alex from Oz said:
OK - there's no room on the baffle for EnABL round the driver bit - the driver goes too close to the edge, but I could EnABL round the outside. Do you think that would be as effective?
You can see that from the pics:
However, I know the sound of these speakers now, I've listened to them a LOT - and they would be easier to A/B because they don't weight 1 tonne each like the Sachikos will!
Alans Pics
Actually, I have not seen any thread that had accomplished this.auplater said:
Of course it could! That's the WHOLE POINT of carefully designed tests... separating the wheat from the chaff... seems to be a HIGHLY unpopular goal here.. probably because it takes alot of work to do it right...
This is exactly the faulty logic that seems rampant on this wandering thread... placebo effect is placebo effect. If the testing conditions are set up correctly, all expectation effects (whether supporting the hypothesis or the null) will be exposed. Your argument only demonstrates your lack of understanding the reality of honest testing.
back to lurking mode...
John L.
Re: Re: Re: Re: Re: Re: Re: Re: Philips DVD Home Theater System HTS3455
Has anybody made a measurement of a full-range driver such as that one before/after the dust cap was replaced with the "phase" plug? My understanding is that it is a full-range driver. The dust cap ,even inside a whizzer, is often used to add to the top end. If you eliminate that dust cap, you're likely to reduce the upper end frequency response.
Has anyone actually documented the change? Consider that the driver designer would likely have tested quite a number of variations, including this I suspect. The off-axis also is an issue, so to show what is really changing, this area must be included in analyzing the change.
Dave
Alan Hope said:
Has anybody made a measurement of a full-range driver such as that one before/after the dust cap was replaced with the "phase" plug? My understanding is that it is a full-range driver. The dust cap ,even inside a whizzer, is often used to add to the top end. If you eliminate that dust cap, you're likely to reduce the upper end frequency response.
Has anyone actually documented the change? Consider that the driver designer would likely have tested quite a number of variations, including this I suspect. The off-axis also is an issue, so to show what is really changing, this area must be included in analyzing the change.
Dave
Re: Re: Re: Re: Re: Re: Re: Re: Re: Philips DVD Home Theater System HTS3455
Indeed they have. And also described a slight loss of highs. In my
own speakers there was perhaps a slight loss of edginess. I wasn't
for going back (even if I could) unlike the time I put on too much
Microgloss and mega-lost some highs!
Phase Plug Graphs
dlr said:
Indeed they have. And also described a slight loss of highs. In my
own speakers there was perhaps a slight loss of edginess. I wasn't
for going back (even if I could) unlike the time I put on too much
Microgloss and mega-lost some highs!
Phase Plug Graphs
Agreed, stated more clearly, a transverse wave in the cone at the VC propagares outward generating an acoustic wave in air.BudP said:
Not entirely incorrect, but I would argue that the vast majority of the energy transferred to the surround is dissipated in the surround. The majority of any energy transferred to the baffle is through the basket. Remember any force applied to the VC by the motor generated and opposing force applied to the motor/basket/baffle... Wave shape is also up for grabs near the cone surface but it's not important.
I would strongly disagree here. The wave will not travel on the surface for several reasons. First, the reflected waves (in the cone) are not generated at the surface. They are predominantly generated when the wave in the cone reaches the outer edge of the cone and is reflected back from the edge. Second, for the wave to be confined to the surface its wave length would necessarily be much shorted than the cone thickness. We have discussed this before.
Difficult to interpret what you are saying exactly here, but the just seems to be less time smear and more dissipation of standing waves. Let me address standing wave first. We have been here before. All the measurements presented clearly show that enable does NOT significantly alter the energy decay of the driver. The data has shown shifts in resonant frequencies, better dissipation at some frequencies, less at others, etc. This is hard physical evidence that application does not impact standing wave behavior. With regard to time smear, assuming that the cone material is homogeneous and isotropic to start with then waves would propagate outward from the VC uniformly in time. There would be no time smear. Application of the enable pattern could only introduce inhomogeneity and anisotropy which would generate, not eliminate time smear.
Again, hard to uderstand what you mean here, but before you can extablish if a wave type is eliminated you have to establish it is present to start with. And there is no evidence in any of the data presented in thei thread that any of this is a relaity. The data contradicts all these specualtions. again, we've been through this time and time again.
Please define still air boundary layer? It sound like all that is meant is either an acoustic BL or just an obscure means of expressing a material interface. We have discussed both and shown that neither can have a significant impact on the performance of the cone.
It was pointed out before by someone other than me, these type os experiments are not appropriate or relevant to what is happening here. We are delaing with transverse waves in a thin material and 3 dimentisonal wave in air.
Continued.....
It's hard to understand what is meant by "constructing the energy transfer process". The energy transfer is purely mechanical due to the velocity of the surface at the air interface. I won't even begin to discuss turbulence other than to say it should be obvious to everyone that if any form of turbulence is introduced it would be detrimental since it would introduce noise.
Ok a BL is as I suspected, just another way of saying material interface. We have been through that. The energy transfer is purely mechanical. Seem strange that you would bring solitons into the argument. It sort of comes from nowhere and really isn't relevant to acoustic wave propagation at all. I won't address it because I won't think it would be well understood by many looking in here.
I would have to say that Ned was mistaken. As I said above, there will be little energy transmitted to the baffle through the cone and surround. Any motion of the baffle is far more dependent on the force balance between driver frame and box/baffle structure. And the math is pretty simple. I've done it.
Partly correct. Yes the transvers wave moves at the wave speed in the material in which it is propogating but the form of the wave transmitted to the surroundings is dependent on the wave speeds in both. In other words, the acoustic wave produce in helium would be different than that in air.
This is where this breaks down seriously. The reason is because we are not talking about an acoustic wave propagating in a lager bulk material which impinges on a surface and is then transmitted across that surface or reflected back. If that were that case we already know that a thin layer of material applied to the bulk have no effect on the wave transmission to the air.
What we have is the propagation of a transverse wave in the cone (or cone plus acrylic layer) and what generates the acoustic wave in air is the displacement on the surface at the air interface. Remember we are dealing with a transverse wave in the cone. Again, don't misunderstand the event (as per Ned). If you apply an acrylic layer uniformly on the cone it isn't the means of energy transfer that changes so much as that we must now determine how that applied layer alters the transverse wave. This can be thought of as a change in cone material in a first order approximation. But the key here is that this reverts back to a structural problem in the cone of how the transverse wave propagates through this new, layered cone and what the resulting surface velocity is. The added layer means the cone now has different effective density, compliance and dissipative properties and it will respond differently to a stimulation applied at the voice coil than an un-layered cone, even in a vacuum. The energy exchange at the interface is still a result of the requirement of continuity of velocity and force (or pressure) (see for example, Mores and Ingard, Theoretical Acoustics).
What ever.
I would suggest you heard what you wanted to hear. Certainly whatevery you believe, it isn't diffraction related.
Well I think the problem here is that both you and Ned have focus on the wrong aspect of the problem. It seems you have been looking at the energy transfer with the implication that it changes drastically. That isn't going to be the case. You could build the cone entirely out of acrylic and it would not change the energy transfer from the surface to the air significantly. The area of focus should be on how the modifications alter the transverse wave propagation and decay, both with regard to the enable pattern and the acrylic coating, and what this means in terms of the changes in the surface velocity of the cone. And I reiterate that since the result of changes in the surface velocity are manifested in the acoustic wave incident upon a measurement mic then the result of these changes are easily identified by looking at the response and any processing of it we may care to do, be it frequency response, step response, CSD, burst, THD, IM, etc. As long as you focus on the energy exchange between surface and air you will not make any progress here because that is not where the action is. It’s all in the mechanical behavior of the cone, be it added mass, increased damping, increase compliance, introduction of inhomogeneities or anisotropy. As they say, it ain’t the meat, it’s the motion....
Re: Re: Re: Re: Re: Re: Re: Re: Re: Philips DVD Home Theater System HTS3455
http://www.geocities.com/rbrines1/Pages/Articles/Phase_Plugs/Phase_Plugs.html
dave
dlr said:
http://www.geocities.com/rbrines1/Pages/Articles/Phase_Plugs/Phase_Plugs.html
dave
Phase Plug Performance
Concerning Bob Brines' phase plug data with the Fostex FE167E referenced by Planet 10:
The off axis response of this driver above 2000 Hz of this driver is exceptionally rough beyond 30 degrees with or without the phase plug. But, if you focus on the on-axis to 15 degrees off performance, it is clear that the phase plugs cause more variability in the response. The valleys are deeper and while so of the dips have moved, the overall response is rougher. I don't see how the sound would be better in any way with the phase plugs versus without.
Other drivers may or may not perform similarly to the FE167E. However, these results are a case for saving your money and not buying phase plugs. You would be better off buying a better driver than fooling with phase plugs on the FE167E.
Concerning Bob Brines' phase plug data with the Fostex FE167E referenced by Planet 10:
The off axis response of this driver above 2000 Hz of this driver is exceptionally rough beyond 30 degrees with or without the phase plug. But, if you focus on the on-axis to 15 degrees off performance, it is clear that the phase plugs cause more variability in the response. The valleys are deeper and while so of the dips have moved, the overall response is rougher. I don't see how the sound would be better in any way with the phase plugs versus without.
Other drivers may or may not perform similarly to the FE167E. However, these results are a case for saving your money and not buying phase plugs. You would be better off buying a better driver than fooling with phase plugs on the FE167E.
I should let Bob speak for himself, but as i understand it, after his initial comments based on the measures, extended listening has him preferring the speakers with phase plugs (based on comments from more recent posts).
I have had a few comments about less top end, but no comments that weren't positive, and many that are quite enthusiastic.
Another case of the limited measuring technology we have not telling the whole story?
dave
I have had a few comments about less top end, but no comments that weren't positive, and many that are quite enthusiastic.
Another case of the limited measuring technology we have not telling the whole story?
dave
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