dlr said:
What if you could rule out one of those issues and loosen the testing criteria slightly? It might not be as rigorous as a full blown and uncompromising investigation but it would allow for more insight. Of course you'd have to be careful not draw firm conclusions from this relaxed testing but at least you'd have a foundation and direction that's more than just rhetoric and hypothesis and philosophy. It would be simpler to implement than the aforementioned full blown investigation as well.
For example, and just for the curiosity of investigating, the power response deviations brought about from changing on axis amplitude with equalisation could be made much less of an issue with semi anechoic testing.
If you relaxed the idea of distortion being changed than that would allow for more scope - I assume that we're only talking about very minor 1-2dB changes made with the EQ, if not then it might be a significant factor. Both drivers would also have to pass through the same processing so as not to bring into question the transparency of the EQ - for this I'd suggest EQing both drivers flat.
From here you could measure aspects and keep in mind that their validity isn't absolute(I don't think any testing regime would be though).
Then comes the listening.
Its hardly ideal but is fairly easily done and would allow some insight into the argument of the only perceived improvement is through amplitude change. If you could level the FR between drivers and still hear and measure worthwhile differences that aren't accountable to testing methodology then at least you could say its not all down to FR. After that other avenues might open up and give more targeted measurements.
ShinOBIWAN said:
For testing such as this to be valid, you have to either eliminate all influences not tested or be able to take non-controllable variables into account. This is why tests of audibility are so difficult if any level of confidence in the results is to be attained. And the variables are not just about the driver itself.
Not really. The problem is that even if the FR could be equalized, the distortion profile will be different if the raw driver frequency response has been altered. That's actually the only significant difference that should then exist after equalization. I'm sure that I've likely missed some other important considerations as well, such as voice coil heating altering the transfer function, etc. It's just not as simple as one would think it might be.
Dave
soongsc said:
There is no reason to assume the flow will be turbulent. Remember this is acoustics. The flow velocities are very small. Nowhere near the level required to generate turbulence. And a bump, no matter how high, does not imply turbulence.
dlr said:
If you remember a while ago I posted a comment about pistonic motion and the idea that pistonic is just a label, like baffle step is a label. Both apply to phenomena that looks different depending on frequency but is really the same. Like baffle step, pistonic motion is just a region of bending wave radiation where the wave length it very long relative the, for example, the driver radius. For long wave lengths the outward movement of the cone starts at the VC/cone junction and this disturbance propagates outward at the speed of sound in the cone. By the time the disturbance get to the surround the outward displacement at the VC does not change significantly relative to the full amplitude of the motion. Thus the variation in displacement along the cone radius can be neglected. (The propagation time across the cone is short compared to the period of oscillation.) At higher frequencies the VC to surround distance can be multiple wave lengths and we see the propagation of several cycles of the bending wave along the way. However, in either case the wave radiated by the cone leaves the cone at an angle which is related to the speed of sound in both the cone and air. But the boundary layer isn't this issue here. If you look at, for example waves propagating in a duct and look at the attenuation due to the acoustic BL it turns out that at high frequency it isn't very different than the attenuation of an acoustic wave in free air. But in either case for there to be significant attenuation due to an acoustic BL the wave must travel much greater distances than the radius of the driver, at any frequency. And, in case I wasn't clear above, the effect the acoustic BL can have on the enable patches is to make there impact less than it would be if the presence of the BL is ignored. Remember, the BL is there with or without the patches.
To envision what happens when an acoustic wave encounters the front edge of an enable patch we can look at what happens when a car runs over a bump. The tires represent the BL. If you are on a perfectly flat road and then the road surface move up 1/16" you don't notice anything when you go over the rise. But if the rise is 6" or 1' you get quite a shock. But now consider the same events with perfectly rigid tires (no BL). You will feel both bumps now but the smaller bump will still have a lesser effect. Ignoring the BL yields the worst case interaction (the biggest effect).
What I am basically talking about here is small diffraction effects caused by the patches. We have already looked at the effects of the added mass and damping on the mechanical vibrations.
dlr,
The worrisome thing about this comment is that it does not apply to a properly EnABL'd driver. The differences in descriptive information are not subtle, as opposed to they way much simpler differences in tone or amplitude are. This invention of term indicates the resolution of finely detailed structure of resonances, that comprise the note of even the simplest musical instrument, and musical instrument reproduction is the figure of merit here, not the testable results from the typical test equipment.
Those testable results, useful as they are, do not address the complex structure of resonances, that comprise intelligibility. As I have stated right from the beginning, it is not a grossly measurable event, and both you and John K have shown this to be true. Your measurements have shown change, but not on a scale that represents the scale of difference, in intelligible information, that EnABL provides.
I do agree that a pulse test provides all possible resonances and the CSD shows their decay, but neither indicate, except in the grossest manner, what level of intelligibility of information might be portrayed.
I am in no way negating what has been presented to date. I must admit that I like John K's deep mesh, of interdependently sprung particles. This is the reality of the diaphragm.
We have come to the point where, apparently, all of us accept that these "sprung" masses are moved with, respect to one another, by transverse waves, traveling through this mesh. These springs also have a gradient to their compression or extension that varies with the amount of energy applied, as an acceleration from one sprung mass to another. Large accelerations tend to lock the springs, reducing compliance and causing the entire mesh to move as a piston.
As you point out, the transverse wave moves through the diaphragm mesh faster than a compression wave moves through air. In an untreated diaphragm this mismatch between excitation of the mesh and the compression wave creation speed, are the cause of all of the breakup modes in a typical driver. This is what I postulate (like that?) is the cause of lack of intelligibility in drivers.
EnABL does overcome this event and since it has been shown that it's mass loading of the cone, while observable, is not significant, when compared to other mass loadings, some other factor is at work. This factor has to be able to force the energy that is being transformed, from the movement of the transverse wave through the mesh, into a correctly located in time compression wave, in the adjacent air.
This means that all of the energy (or nearly that) must arise off of the join between mesh and air, at an appropriate moment. That moment being as the compression wave joining edge, sweeps across the mesh surface. I view this as a bubble that is expanding. With a structure that significantly mimics that of an expanding bubble, at it's termination on the boundary layer, of the surface it is arising from.
The EnABL terminations appear to provide the circumstances that allow this coherent transform to occur, I see no other possible medium, than the boundary layer. This is not a boundary layer created by blown air, it is still, no lateral movement. The EnABL patterns cause this boundary layer to be established in a continuous fashion across the diaphragm and disallows energy reflections that would disrupt it..
I suppose a visualization might be of yet another storage mechanism being created and energy being stacked within it, across the diaphragm, and transforming into the compression wave, as that compression wave sweeps across this boundary layer. Only because it is now the most efficient means of transformation. Again, in a fashion very similar to how a bubble is supported on the surface of water.
I absolutely think this also occurs without EnABL, but, it is not a stable situation, because the boundary layer is not thick enough and the compression wave transformation point "crashes" into the out of time energy, in compression wave format, arising from the diaphragm, before the major wave front gets there.
This major wave front, being the one that arises at the joint of the voice coil and diaphragm. The out of time compression waves being ones that are emitted, from various parts of the cone, as the transverse wave traverses the mesh, faster than the speed of a compression wave front, through adjacent air.
I do think that John K's CSD plots, that show an alternation between treated and untreated cone, show this activity. There is less disturbance in the decay and the large format energy peaks are much more clearly defined. And I think that this is important here.
The removal of those peaks is not the business of EnABL, even though Sonngsc has shown, that it is possible to use the patterns for this. The actual benefit EnABL is providing is in clarification and that this is actually found in a blink comparison of the CSD plots.
The rest of the job is being done within the correlator that constructs "meaning" from movement of hair follicles, in a long, hot, cave of fleshy substance, coated in wax, dirt, dead fleshy bits and the creatures that thrive in this environment.
Please keep hammering away Dave, John K, ronc, Planet 10 Dave Soongsc, ShinOBIWAN, auplater and all of the rest of you too.
John K, could you put back up on your site just the treated/untreated CSD plots? The rest are interesting too, but I suspect you removed them due to their proprietary nature, once you saw just how interesting the thoughts they caused to arise were. Don't blame you either, a lot of interesting possibilities there, for helping to linearize the deep mesh behavior.
Bud
The worrisome thing about this comment is that it does not apply to a properly EnABL'd driver. The differences in descriptive information are not subtle, as opposed to they way much simpler differences in tone or amplitude are. This invention of term indicates the resolution of finely detailed structure of resonances, that comprise the note of even the simplest musical instrument, and musical instrument reproduction is the figure of merit here, not the testable results from the typical test equipment.
Those testable results, useful as they are, do not address the complex structure of resonances, that comprise intelligibility. As I have stated right from the beginning, it is not a grossly measurable event, and both you and John K have shown this to be true. Your measurements have shown change, but not on a scale that represents the scale of difference, in intelligible information, that EnABL provides.
I do agree that a pulse test provides all possible resonances and the CSD shows their decay, but neither indicate, except in the grossest manner, what level of intelligibility of information might be portrayed.
I am in no way negating what has been presented to date. I must admit that I like John K's deep mesh, of interdependently sprung particles. This is the reality of the diaphragm.
We have come to the point where, apparently, all of us accept that these "sprung" masses are moved with, respect to one another, by transverse waves, traveling through this mesh. These springs also have a gradient to their compression or extension that varies with the amount of energy applied, as an acceleration from one sprung mass to another. Large accelerations tend to lock the springs, reducing compliance and causing the entire mesh to move as a piston.
As you point out, the transverse wave moves through the diaphragm mesh faster than a compression wave moves through air. In an untreated diaphragm this mismatch between excitation of the mesh and the compression wave creation speed, are the cause of all of the breakup modes in a typical driver. This is what I postulate (like that?) is the cause of lack of intelligibility in drivers.
EnABL does overcome this event and since it has been shown that it's mass loading of the cone, while observable, is not significant, when compared to other mass loadings, some other factor is at work. This factor has to be able to force the energy that is being transformed, from the movement of the transverse wave through the mesh, into a correctly located in time compression wave, in the adjacent air.
This means that all of the energy (or nearly that) must arise off of the join between mesh and air, at an appropriate moment. That moment being as the compression wave joining edge, sweeps across the mesh surface. I view this as a bubble that is expanding. With a structure that significantly mimics that of an expanding bubble, at it's termination on the boundary layer, of the surface it is arising from.
The EnABL terminations appear to provide the circumstances that allow this coherent transform to occur, I see no other possible medium, than the boundary layer. This is not a boundary layer created by blown air, it is still, no lateral movement. The EnABL patterns cause this boundary layer to be established in a continuous fashion across the diaphragm and disallows energy reflections that would disrupt it..
I suppose a visualization might be of yet another storage mechanism being created and energy being stacked within it, across the diaphragm, and transforming into the compression wave, as that compression wave sweeps across this boundary layer. Only because it is now the most efficient means of transformation. Again, in a fashion very similar to how a bubble is supported on the surface of water.
I absolutely think this also occurs without EnABL, but, it is not a stable situation, because the boundary layer is not thick enough and the compression wave transformation point "crashes" into the out of time energy, in compression wave format, arising from the diaphragm, before the major wave front gets there.
This major wave front, being the one that arises at the joint of the voice coil and diaphragm. The out of time compression waves being ones that are emitted, from various parts of the cone, as the transverse wave traverses the mesh, faster than the speed of a compression wave front, through adjacent air.
I do think that John K's CSD plots, that show an alternation between treated and untreated cone, show this activity. There is less disturbance in the decay and the large format energy peaks are much more clearly defined. And I think that this is important here.
The removal of those peaks is not the business of EnABL, even though Sonngsc has shown, that it is possible to use the patterns for this. The actual benefit EnABL is providing is in clarification and that this is actually found in a blink comparison of the CSD plots.
The rest of the job is being done within the correlator that constructs "meaning" from movement of hair follicles, in a long, hot, cave of fleshy substance, coated in wax, dirt, dead fleshy bits and the creatures that thrive in this environment.
Please keep hammering away Dave, John K, ronc, Planet 10 Dave Soongsc, ShinOBIWAN, auplater and all of the rest of you too.
John K, could you put back up on your site just the treated/untreated CSD plots? The rest are interesting too, but I suspect you removed them due to their proprietary nature, once you saw just how interesting the thoughts they caused to arise were. Don't blame you either, a lot of interesting possibilities there, for helping to linearize the deep mesh behavior.
Bud
Bud, I don't accept a single part of the description of what you hypothesize is occurring. A treatment of a driver has to change the transfer function and may as an incidental effect alter the distortion profile. It can be no other way. This is regardless of any mechanism involved. The central issue outside of that is the acoustic output of the driver as measured or heard. Neither one makes a distinction as to the source.
If a treatment changes the transfer function of the driver, then no matter what frequencies are involved, they can be measured, either in the FR or in distortion measurements. The key is making the correct measurements. Intelligibility means nothing with regard to measurements, though ALL frequencies that can have an impact on intelligibility are represented in measurements in one way or another. You're trying to say that we can hear what can't be measured in a driver's raw response because you believe that your perception says so. I reject that outright. The root of what might change "intelligibility" is in determining the measurements that ferret out the differences causing that effect in perception. The acoustic output, all of it and any of it affecting perception, can be measured if the desire is there and the effort is made. Measurement systems with the capability to do this exist. It may take some serious effort, but that's the price to pay.
Dave
If a treatment changes the transfer function of the driver, then no matter what frequencies are involved, they can be measured, either in the FR or in distortion measurements. The key is making the correct measurements. Intelligibility means nothing with regard to measurements, though ALL frequencies that can have an impact on intelligibility are represented in measurements in one way or another. You're trying to say that we can hear what can't be measured in a driver's raw response because you believe that your perception says so. I reject that outright. The root of what might change "intelligibility" is in determining the measurements that ferret out the differences causing that effect in perception. The acoustic output, all of it and any of it affecting perception, can be measured if the desire is there and the effort is made. Measurement systems with the capability to do this exist. It may take some serious effort, but that's the price to pay.
Dave
dlr said:
OK so that's a non starter but by being almost religious about your approach and demands aren't you in fact shooting down your own idea's. Surely you could always argue that the accuracy of the results is in question. It becomes even more of a minefield when you try to relate this data to the subjective qualities and state conclusive what enable changes/improves and why it does so.
I'm normally one to take a similar rigour to yourself but in this case I don't know if that's a good or bad thing to be honest.
ShinOBIWAN said:
I didn't think so. I don't recall where I made that point in the way you do, if so I'll correct it. My position is that any two drivers to compare must first be closely matched prior to any mod. Then any differences must be associated with the mod. Differentiating the changes isn't easy, since you can't separate the distortion from anything else, even equalized due to there being more than one variable. But measurements can be made to show what distortion components did change. How they changed (mechanism) is another question altogether.
Dave
BudP said:
Nothing "locks". There are no accelerations which stress the cone material beyond its elastic limits. To do so would permanently deform the cone. As long as we remain in the elastic region the "springs" remain linear. There are no “bump stops”.
The mismatch has noting to with the breakup. Breakup a function of the geometry and material of the mechanical system. Air mass loading must be considered, but breakup would occur in a vacuum.
Since the premise is incorrect, so must be the postulate.
Yes, something else may be at work. But the problem is that since we are dealing with wave propagation what is radiated off the cone is radiated before the wave reaches the outer enable pattern. The wave doesn’t know the pattern is there until it gets there. What ever happens there must lag the original wave by at least the time it takes a wave to propagate to the cone edge. It’s like dropping a glass. Changing the characteristic of the floor does change how the glass falls. It can only affect the outcome of what happens after the glass hits the floor.
Well that's the problem, isn't it? If there isn't any lateral movement there isn't any BL. Furthermore, the enable pattern can't establish anything. It can only alter what is established when no treatment is present. If there is a BL, it doesn't prevent reflections.
I think you might need to study how an acoustic wave is launched off a diaphragm as the bending wave propagates across it.
Sorry. I delete them. I didn't save them.
dlr,
You might want to re read that rambling post. I most explicitly pointed out a general characteristic, that was shown in the CSD plots, that, whether incidentally or not, portrays what the subjective evaluation of an EnABL'd driver does provide. Not saying that the two are related, I don't know that they are.
I also echoed John K in pointing out that it could not be completely explained from a mass loading point of view.
I now agree that everything EnABL does is to be found in the current tests. I actually agreed with that before. It's just that I could not find it. So far we still only have anecdotal test results, that may be portraying it's effects, in an easily seen CSD blink comparison. To me, these are unique portrayals of a CSD plot, not something I have ever had, to look at and think about. Thanks John.
Dave, I am glad that you are defending a conservative view of these events. This is a necessary part of this investigation. As Soongsc has already hinted at, with his comments and occasional CSD pots, EnABL is really just a scratch on the surface, of a body of knowledge yet to be explored. How much of an expression of that knowledge EnABL patterns are, is not known. My thought is not more than perhaps 10%, of what will eventually be put to work in perfecting loudspeakers.
No doubt about the importance of what John K looked at, with mass loading a cone. No doubts at all. But speaking from a pretty large body of treatment, of many diverse types of drivers, EnABL would still provide that removal of incoherency, that is the single most obvious benefit to it's use.
Dan Wiggins made the comment to me, that he was satisfied with the current level of motor refinement, spider and surround refinement. His next interest was to find out how to refine the actual diaphragm and that the patent search he had performed turned up what he thought would a good place to begin, EnABL.
Bud
You might want to re read that rambling post. I most explicitly pointed out a general characteristic, that was shown in the CSD plots, that, whether incidentally or not, portrays what the subjective evaluation of an EnABL'd driver does provide. Not saying that the two are related, I don't know that they are.
I also echoed John K in pointing out that it could not be completely explained from a mass loading point of view.
I now agree that everything EnABL does is to be found in the current tests. I actually agreed with that before. It's just that I could not find it. So far we still only have anecdotal test results, that may be portraying it's effects, in an easily seen CSD blink comparison. To me, these are unique portrayals of a CSD plot, not something I have ever had, to look at and think about. Thanks John.
Dave, I am glad that you are defending a conservative view of these events. This is a necessary part of this investigation. As Soongsc has already hinted at, with his comments and occasional CSD pots, EnABL is really just a scratch on the surface, of a body of knowledge yet to be explored. How much of an expression of that knowledge EnABL patterns are, is not known. My thought is not more than perhaps 10%, of what will eventually be put to work in perfecting loudspeakers.
No doubt about the importance of what John K looked at, with mass loading a cone. No doubts at all. But speaking from a pretty large body of treatment, of many diverse types of drivers, EnABL would still provide that removal of incoherency, that is the single most obvious benefit to it's use.
Dan Wiggins made the comment to me, that he was satisfied with the current level of motor refinement, spider and surround refinement. His next interest was to find out how to refine the actual diaphragm and that the patent search he had performed turned up what he thought would a good place to begin, EnABL.
Bud
dlr said:
OK thanks for the clarification. I haven't read all the thread but what, aside from FR and CSD, does enable change?
Golly! We have lots of philosophers here.😀
Was wondering what material John K used for his patterns. Has anyone seen pics of it?
dlr provided nice pics, but none seem to ressemble the EnABL in any way.
Was wondering what material John K used for his patterns. Has anyone seen pics of it?
dlr provided nice pics, but none seem to ressemble the EnABL in any way.
To consider the effects of the BL on the enable process consider three cases: 1) the BL is much thicker than the height of the patch. The result is effectively that the patch as no effect for several reasons. The BL thickness goes like sqrt (1/f) = sqrt (WL/C) where WL = wave length and C is sound speed. If the BL is much thicker than an enable patch then the wave length is even bigger relative the enable patch. The enable patch is buried well inside the BL and has little effect on anything.
Well at least we agree on one thing John. In my dynamic sims i saw that the height of the deflectors had to be greater to provide any effect, and as the wavelength was longer the height had to be greater ( common sense here). IMHO putting dots on a baffle surface where the wavelength is longer and lifts away from the surface would have no effect. At higher frequencies on the cone surface, it could, but still would be frequency/height of the deflector/ Z value of the deflector dependant.
As far as change due to mass loading, that should be an easy calculation if we know the density/volume of the applied medium. However i would be surprised if it actually changed the Qms. To me if a raising of the Qts is required , its easier to add a resistor.
ron
Well at least we agree on one thing John. In my dynamic sims i saw that the height of the deflectors had to be greater to provide any effect, and as the wavelength was longer the height had to be greater ( common sense here). IMHO putting dots on a baffle surface where the wavelength is longer and lifts away from the surface would have no effect. At higher frequencies on the cone surface, it could, but still would be frequency/height of the deflector/ Z value of the deflector dependant.
As far as change due to mass loading, that should be an easy calculation if we know the density/volume of the applied medium. However i would be surprised if it actually changed the Qms. To me if a raising of the Qts is required , its easier to add a resistor.
ron
ronc said:
We are probably in closer agreement than you think. Probably some initial miss communications as is likely to happen over the internet with delayed responses, etc. I would also doubt any significant changes in Qtms due to the application of a true enable pattern. The effect on breakup would be more likely due to inhomogeneous cone properties after treatment and local increases in mass. After that, as far as I am concerned it’s all diffraction cause by the bumps. Since the bumps are small the diffraction effects have to be small as well. But as far as energy re-absorption and re-radiation I don't believe that can be an issue for several reasons. Among them is that the waves passing over the cone or baffle are at very shallow incidence so very little energy can be transmitted, and the large differential in acoustic impedance means that even for head on impingement there is very little energy transmitted and re-radiated compared to what is reflected.
Ron and John,
Here is the only information I can supply on the amount of mass added to the diaphragm of a cone speaker.
The first is from auplater with info on acrylic.
post 1560
http://www.diyaudio.com/forums/showthread.php?postid=1396976#post1396976
The second is a somewhat loose calculation of material actually placed on a cone and what it's rough thickness is, when the same pen load is applied to Mylar sheet and fully dried.
post 1574
http://www.diyaudio.com/forums/showthread.php?postid=1397352#post1397352
These two posts might begin to give you a feel for how much mass is left after full cure. Before gloss coat and after.
Bud
Here is the only information I can supply on the amount of mass added to the diaphragm of a cone speaker.
The first is from auplater with info on acrylic.
post 1560
http://www.diyaudio.com/forums/showthread.php?postid=1396976#post1396976
The second is a somewhat loose calculation of material actually placed on a cone and what it's rough thickness is, when the same pen load is applied to Mylar sheet and fully dried.
post 1574
http://www.diyaudio.com/forums/showthread.php?postid=1397352#post1397352
These two posts might begin to give you a feel for how much mass is left after full cure. Before gloss coat and after.
Bud
ShinOBIWAN said:
Shin and Dave..would it give us better results if rather than enabling one driver and then eq'ing that and another flat and taking it from there, you (Shin I guess) would eq a driver flat, then w/out taking the driver from the test baffle (ie apply the enable in situ) and w/out touching the mic at all, then the only change is the enable and remeasure.
Now that I've gone and typed that I can't see any difference in what has already been done...so forget it I suppose.
Still, would be good if one of the skeptics could do a blind listening test on a treated driver vs untreated driver and see what happens. Otherwise we are just gonna tawk about this forever.
and local increases in mass.
This could be the answer if you look at it in a deeper sense. Different mass values positioned at different points would disrupt the continunity of the energy being transferred as the wave travelled over the surface.
I need to think on this.
and the large differential in acoustic impedance means that even for head on impingement there is very little energy transmitted and re-radiated compared to what is reflected.
I agree.
ron
This could be the answer if you look at it in a deeper sense. Different mass values positioned at different points would disrupt the continunity of the energy being transferred as the wave travelled over the surface.
I need to think on this.
and the large differential in acoustic impedance means that even for head on impingement there is very little energy transmitted and re-radiated compared to what is reflected.
I agree.
ron
90 odd pages later and most important thing I take away from the discussion is that enable pattern treatment in some fashion modifies energy storage and dissipation of diaphragm materials.
Also we can ask how does it do that? Is there more than one mechanism at work? Lots of pages spent on that.
Can the effect be measured? Looks like it.
Then there are questions about "subjective" effect.
Lots of discussion. The consensus seems that it can't be measured.
Perhaps so, but psychoacousticians have done a great deal of scientific investigation into what it is possible to hear, so if we take the trouble to investigate what they've done, we can probably safely conclude some effects of enable treatment may or may not be audible.
Relatedly, not enough attention is given to participants' descriptions of what they've heard in before and after enabl treatments as an indicator for investigation. A gross summary of their descriptions: They hear musical stuff they couldn't hear before; especially low level musical stuff.
They are describing a masking effect.
The most common masker in our day to day environment is noise. Noise: signal containing a random or semi-random distribution of frequencies possibly with energy peak(s) distributed around some center frequency(s).
Example: Using my Ratshack meter, the noise floor in my room in a concrete building I'd guess is a bit less than 50dB, on the balcony outside it in the metro environment about 60dB. If I play a recording I know well at an average level of 70 dB and stand just outside the open door I find there's a whole lot of low level musical stuff I can't hear. Even if I sit inside 12 feet away from the open door the noise from outside obscures some low level musical stuff - the speakers sit either side of the door - even though the meter only measure 53 -54 dB outside noise at this listening position.*
This is surely not rigorous but it does indicate not very many dBs of noise can make a noticeable difference to the amount of music I can actually hear.
The participants' descriptions suggest a direction for investigation: How much noise does a speaker produce when it plays music? Does level of this noise follow the amplitude of the musical signal? If it does, are changes in noise amplitude linear or non-linear? Does this noise have higher energy distribution around certain frequencies? How about before and after enable treatment?
What's the best way of getting the noise produced by the speaker diaphragm? Can we assume the enabl treatment will have little effect on the electrical parameters? I think we can because it didn't seem to have a great effect on the phase.
What's the best way of looking at noise?
...........................................................
*(I think I could sharpen this whole thing up by playing music through one speaker, putting another speaker on it and playing white or pink noise through the second and measuring when noticeable difference in the musical presentation is apparent. I could have somebody behind me run the levels for the noise).
Also we can ask how does it do that? Is there more than one mechanism at work? Lots of pages spent on that.
Can the effect be measured? Looks like it.
Then there are questions about "subjective" effect.
Lots of discussion. The consensus seems that it can't be measured.
Perhaps so, but psychoacousticians have done a great deal of scientific investigation into what it is possible to hear, so if we take the trouble to investigate what they've done, we can probably safely conclude some effects of enable treatment may or may not be audible.
Relatedly, not enough attention is given to participants' descriptions of what they've heard in before and after enabl treatments as an indicator for investigation. A gross summary of their descriptions: They hear musical stuff they couldn't hear before; especially low level musical stuff.
They are describing a masking effect.
The most common masker in our day to day environment is noise. Noise: signal containing a random or semi-random distribution of frequencies possibly with energy peak(s) distributed around some center frequency(s).
Example: Using my Ratshack meter, the noise floor in my room in a concrete building I'd guess is a bit less than 50dB, on the balcony outside it in the metro environment about 60dB. If I play a recording I know well at an average level of 70 dB and stand just outside the open door I find there's a whole lot of low level musical stuff I can't hear. Even if I sit inside 12 feet away from the open door the noise from outside obscures some low level musical stuff - the speakers sit either side of the door - even though the meter only measure 53 -54 dB outside noise at this listening position.*
This is surely not rigorous but it does indicate not very many dBs of noise can make a noticeable difference to the amount of music I can actually hear.
The participants' descriptions suggest a direction for investigation: How much noise does a speaker produce when it plays music? Does level of this noise follow the amplitude of the musical signal? If it does, are changes in noise amplitude linear or non-linear? Does this noise have higher energy distribution around certain frequencies? How about before and after enable treatment?
What's the best way of getting the noise produced by the speaker diaphragm? Can we assume the enabl treatment will have little effect on the electrical parameters? I think we can because it didn't seem to have a great effect on the phase.
What's the best way of looking at noise?
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*(I think I could sharpen this whole thing up by playing music through one speaker, putting another speaker on it and playing white or pink noise through the second and measuring when noticeable difference in the musical presentation is apparent. I could have somebody behind me run the levels for the noise).
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