planet10 said:
Actually, no, it reads as a gratuitous slam, seeming to cast doubts on objective measurements, since it was totally unrelated to the book itself. The author made a mistake at some other point in time, therefore cast doubt on a book, even though the other situation was unrelated.
I'll bet he's recognized and has even acknowledged that! That simply shows he's human. But since it's related to the objective, not the subjective, you attempt to cast doubt with a gratuitous slam based on an error. However, the fact that there was an egregious error by all proponents in seeing, much less accepting, that there is distinct FR change (as just one example) due to the EnABL process brought forth no comments of this kind by you nor by any of the others if memory serves. No doubt was cast at all. Why the different approach when it comes to the EnABL process?
Have you spent any time at the Linkwitz site? If you have, I would assume that you have read the excellent material on distortion. That should, I think, answer most questions being posed here as to the ability to measure components in any signal buried far below nominal.
How about when it relates to the EnABL process?
Dave
I don't read it like that. I just see it as:dlr said:
D'Appolito's book is a valuable reference. At one point in time he made a mistake in measurements, which happens to all of us once in a while. But it is also understood that obtaining knowledge from various sources and not just rely on one source is very important.
I have the book as well, and most of the contents are valuable. There were a few things that I did not quite agree with, but I can't even remember what they are because I like to focus on what I accept and learn from rather than nit pick on things I don't agree with.
dlr said:
If you read that into it i'm sorry for you.
Indeed Joe's mistake measuring -- and designing -- the Thor remind us that even those we respect as experts are human and not immune from error. My comment did not slam the book, it was a reminder from one specific objective measurement that noone should blindly believe everything they read,
Certainly there are few books that are without some error... i have on a number of occasions quietly contacted authors about mistakes.
If i don't understand something, or question something i ask.
No one has seen anything from Joe wrt Thor -- but i'd be very surprised if he didn't see the anechoic measures made by SEAS that showed response to ~100Hz.
A growing number of people are now enjoying their FatThors, ShortThors & SmallThors. Subwoofers have been removed from systems.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=64799
dave
dlr said:
I have no issues with that.
But that is not what i asked for... I want to know how much a simultaneous & distinct stimulus is distortied in the presence of a much larger stimulus... 1st the above does not have a 2nd stimulus, and 2nd even if there was it is buried in the distortion from the large stimulus.
John taked about the importance od flat frequency response, but how much do thr FR measures we see tell us about the FR of a simultaneous stimulus in the presense of a larger one.
Because in the end what EnABL does -- it let you hear you hear stuff deep in the dynamic range that you didn't even know was there before EnABL
dave
G'day All,
I went to a friends place today to put the EnABL pattern into the ports of his speakers.
The speakers are Dynalab SDA 2.8 Signature Reference - a well know 'white van' brand.
The important thing to focus on is the effect of the EnABL pattern when applied to the port, not the brand of speaker (or it’s suspect origin).
Specifications of the speaker (copy and paste from internet):
Duel 8" Floor-standing 2-way Tower Speaker Utilizing a 4th Order Butterworth Ported Design - 15 Watts RMS Amp Power, 200 Watts Music Power, 8 ohms, 91B 1W/1M, 100dB, 39-22,000 Hz (+-3dB), 12/6 dB per octave, 4,000 Hz crossover, 2-8" " High Modulus" Bi-Lamented Cone Butyl Rubber Surround, 1 1/2" Dia. High-temp Voice Coil, 24 oz. High Strength Ceramic Magnet, 13mm Titanium Coated Dome Computer Opt. Phase Dispersion Ring Tweeter, all in a wood black veneered finished ported cabinet.
Port & Material Details
Port - 75mm diameter, straight pipe, no flare and front firing
EnABL block size - 5 mm x 2.5 mm (between 9 – 10 block pairs)
Block Material - PVC duct tape (black)
Parts list:
- Scotch Magic Tape (19mm) - (actually I ran out, so on this occassion I used Artrite Invisible tape 19mm)
- Duct tape (PVC)
- Cutting knife or blade
- Cutting Mat
- Ruler
Instructions
1. Lay a strip of Scotch Magic tape sticky side down on a cutting mat
2. Lay a strip of duct tape sticky side down also on the cutting mat
3. Using a blade, cut the duct tape into the right size blocks for the port
4. Pick the blocks off the cutting mat using the blade
5. Lay the blocks on top of the Magic tape in the EnABL pattern
6. Peel up the Magic tape with EnABL'd blocks
Application Details
There was roughly 1 mm between the edge of the magic tape and the blocks.
Stuck the magic tape strip into one end of the port so that the distance from the blocks to the edge of the port opening was roughly 2 mm.
Results
Applied the EnABL pattern to the port of one speaker first and noticed a significant increase in mid range clarity and cleaner, tighter bass - a clearly audible change.
The untreated speaker now sounded louder than the treated speaker and more distorted by comparison.
Applied the EnABL pattern to the second speaker.
Bass became cleaner and tighter and seemed to be generated by the whole room.
Bass transients are much clearer and faster and mid range is more detailed.
These results are consistent with those of previous applications of the EnABL pattern to ports.
I have no idea whether the 9 - 10 block pairs for determining block size is optimal.
It is achieving consistent and clearly audible changes, so it’s a good place to start.
My friend is frustrated that I am unable to explain how this works, but absolutely delighted with the results.
Hopefully I have provided enough detail this time, but I'm happy to answer any questions.
Cheers,
Alex
I went to a friends place today to put the EnABL pattern into the ports of his speakers.
The speakers are Dynalab SDA 2.8 Signature Reference - a well know 'white van' brand.
The important thing to focus on is the effect of the EnABL pattern when applied to the port, not the brand of speaker (or it’s suspect origin).
Specifications of the speaker (copy and paste from internet):
Duel 8" Floor-standing 2-way Tower Speaker Utilizing a 4th Order Butterworth Ported Design - 15 Watts RMS Amp Power, 200 Watts Music Power, 8 ohms, 91B 1W/1M, 100dB, 39-22,000 Hz (+-3dB), 12/6 dB per octave, 4,000 Hz crossover, 2-8" " High Modulus" Bi-Lamented Cone Butyl Rubber Surround, 1 1/2" Dia. High-temp Voice Coil, 24 oz. High Strength Ceramic Magnet, 13mm Titanium Coated Dome Computer Opt. Phase Dispersion Ring Tweeter, all in a wood black veneered finished ported cabinet.
Port & Material Details
Port - 75mm diameter, straight pipe, no flare and front firing
EnABL block size - 5 mm x 2.5 mm (between 9 – 10 block pairs)
Block Material - PVC duct tape (black)
Parts list:
- Scotch Magic Tape (19mm) - (actually I ran out, so on this occassion I used Artrite Invisible tape 19mm)
- Duct tape (PVC)
- Cutting knife or blade
- Cutting Mat
- Ruler
Instructions
1. Lay a strip of Scotch Magic tape sticky side down on a cutting mat
2. Lay a strip of duct tape sticky side down also on the cutting mat
3. Using a blade, cut the duct tape into the right size blocks for the port
4. Pick the blocks off the cutting mat using the blade
5. Lay the blocks on top of the Magic tape in the EnABL pattern
6. Peel up the Magic tape with EnABL'd blocks
Application Details
There was roughly 1 mm between the edge of the magic tape and the blocks.
Stuck the magic tape strip into one end of the port so that the distance from the blocks to the edge of the port opening was roughly 2 mm.
Results
Applied the EnABL pattern to the port of one speaker first and noticed a significant increase in mid range clarity and cleaner, tighter bass - a clearly audible change.
The untreated speaker now sounded louder than the treated speaker and more distorted by comparison.
Applied the EnABL pattern to the second speaker.
Bass became cleaner and tighter and seemed to be generated by the whole room.
Bass transients are much clearer and faster and mid range is more detailed.
These results are consistent with those of previous applications of the EnABL pattern to ports.
I have no idea whether the 9 - 10 block pairs for determining block size is optimal.
It is achieving consistent and clearly audible changes, so it’s a good place to start.
My friend is frustrated that I am unable to explain how this works, but absolutely delighted with the results.
Hopefully I have provided enough detail this time, but I'm happy to answer any questions.
Cheers,
Alex
Attachments
planet10 said:
You are wrong again on both counts, as that test is, as described explicitly by Linkwitz, a fundamental at 150 Hz with a second frequency determined explicitly to be very demanding, even more so than your example of a second signal 40db down that is going to be at the level of the multiple distortion components generated in the first place (I could say "it is buried in the distortion from the large stimulus"). The entire purpose of two stimuli is to examine the distortion that is generated. Linkwitz simply restates the fundamental, it not being necessary to restate the rest.
You should take a bit more time to read a reference, rather than dismiss it with an invalid claim. So I will say again, this should put to the rest the frequently restated questions that have been answered as to the capability to measure signals buried deep in the response of the driver. Denial does not change the facts.
John's points are spot-on, as usual, especially with respect to a system that's not flat at any level. What more is there to say?
Dave
"You'll luv it!" vs. "I don't want too!"
If the wave propagation across the cone encounters an impedance mis-match, is distortion created which is above/beyond (some of) the signal emitted from the cone?...Does this distortion mask or obscure content within the intended signal?...
Is it possible that an EnABL band (set of blocks) presents a different impedance match for the wave propagation?...and that the distortion created by the EnABL band is different from that created by the junction of the cone to surround?
...Further, could that distortion produced by the EnABL band be of a lesser magnitude than that produced by the cone to surround junction?
Bear with me here...Could the wave propagation across the EnABL band result in a lower energy density outside the band, the result of which would be a lower magnitude of distortion produced by the same wave when it encounters the junction of the cone and surround?
...and now...envelope please...How does conventional testing ferret out (disciminate) those elements which appear as a summation in the results?
I dunno, Mongo wants to know.
If the wave propagation across the cone encounters an impedance mis-match, is distortion created which is above/beyond (some of) the signal emitted from the cone?...Does this distortion mask or obscure content within the intended signal?...
Is it possible that an EnABL band (set of blocks) presents a different impedance match for the wave propagation?...and that the distortion created by the EnABL band is different from that created by the junction of the cone to surround?
...Further, could that distortion produced by the EnABL band be of a lesser magnitude than that produced by the cone to surround junction?
Bear with me here...Could the wave propagation across the EnABL band result in a lower energy density outside the band, the result of which would be a lower magnitude of distortion produced by the same wave when it encounters the junction of the cone and surround?
...and now...envelope please...How does conventional testing ferret out (disciminate) those elements which appear as a summation in the results?
I dunno, Mongo wants to know.
Re: "You'll luv it!" vs. "I don't want too!"
All very good questions with important implications. All could be answered if a full set of conventional distortion tests were made before/after and done appropriately, meaning under the exact same conditions (signal level, etc.).
This is been asked and answered several times in the thread.
In a word, yes. Study one or more of the sites previously suggested, Linkwitz, Mark K., zaph with that of Linkwitz being the most extensive. They all describe the requirements to one degree or another. It's all there for anyone to see who wants to learn.
Dave
Ed LaFontaine said:
All very good questions with important implications. All could be answered if a full set of conventional distortion tests were made before/after and done appropriately, meaning under the exact same conditions (signal level, etc.).
This is been asked and answered several times in the thread.
In a word, yes. Study one or more of the sites previously suggested, Linkwitz, Mark K., zaph with that of Linkwitz being the most extensive. They all describe the requirements to one degree or another. It's all there for anyone to see who wants to learn.
Dave
Ed LaFontaine said:
It is harder to learn without having some hands-on time. Linkwitz does a nice job trying to make it readable. I should also point out that John K's sites have much useful information as well.
Music and Design
John's Original Site
Dave
Hi Ed,
Again dozens of pages back I suggested mounting microphones at the edge of two drivers being driven by the same AF. One enabled, the other plain. Amplify those mics by a stereo amplifier and listen to the difference between outputs, or difference wrt reduced input via phones to gain an *real-time* in-head image of what is happening, not just time isolated 'lab' type investigations
Again the 'experts' here created considerable distraction by 'discussing' supposedly better methods available, so no-one checked.
Hi Alex,
You might be able to isolate the Enable induced difference at ports using this method !
Cheers ............ Graham.
Again dozens of pages back I suggested mounting microphones at the edge of two drivers being driven by the same AF. One enabled, the other plain. Amplify those mics by a stereo amplifier and listen to the difference between outputs, or difference wrt reduced input via phones to gain an *real-time* in-head image of what is happening, not just time isolated 'lab' type investigations
Again the 'experts' here created considerable distraction by 'discussing' supposedly better methods available, so no-one checked.
Hi Alex,
You might be able to isolate the Enable induced difference at ports using this method !
Cheers ............ Graham.
Re: "You'll luv it!" vs. "I don't want too!"
Hi Ed,
If you like, picture the cone as being composed of an infinite number of point sources distributed over the radiating surface. These are primary sources. As a transient wave in the cones moves outward through the cone these sources being to radiate sequentially at the time the wave front passes them. These sources lie on the surface, be it the cone surface, the surface of the enable patches or the surface of any coating applied. If the transverse waves in the cone are reflected by any means, then you may picture the reflected waves as giving rise to a number of secondary sources, again which start to radiate when the reflected wave front passes by them. You can envision another set of sources being introduces each time a new wave or reflected wave enters the picture. All these sources radiate at a strength that is a function of the surface velocity of the radiating surface. Since they all start radiating at different times and with different magnitudes, etc, what reaches a mic is the summation of all these sources at each instant in time. Over any given period of time we obtain a time continuous signal. If you change the way the sources behave, by any means, then you must change the way they radiate, and thus the time continuous signal will also change. If there is any additiona diffraction of the acoustic wave in air due to the enable patches it will also be reflected by differences in the time signal. So a direct examination of the time signal radiated from a driver before and after treatment will show the differences. It may not provide insight into exactly how the differences arose, but it will show the differences.
It has been suggested that this will not show the differences because the differences are 40 or 50 dB below the nominal levels. Taking 40dB as the threshold, -40dB is 0.01 relative to 1.0 in a linear scale. But take a look at this figure:
The upper plot is the impulse response of a driver, on axis. The initial rise is to the top of the plot = 1.0. Below is the same impulse blown up by a factor of 100 vertically. Notice that just to the left of the IMP logo is a peak rising to the top of the plot which is an amplitude of 0.01 = -40dB. So clearly information at -40dB is in the time response. In fact, just to the right of that peak we can see that there is a peak at about 1/2 scale or -46dB.
I said long ago and, as usual it was dismissed. But here we are with the evidence staring us in the face. A conventional measurment will show the changes. And once we have the time response we can process it as we like, Frequency response, CSD, Burst, Step, etc. All just different ways to display the same data.
Ed LaFontaine said:
Hi Ed,
If you like, picture the cone as being composed of an infinite number of point sources distributed over the radiating surface. These are primary sources. As a transient wave in the cones moves outward through the cone these sources being to radiate sequentially at the time the wave front passes them. These sources lie on the surface, be it the cone surface, the surface of the enable patches or the surface of any coating applied. If the transverse waves in the cone are reflected by any means, then you may picture the reflected waves as giving rise to a number of secondary sources, again which start to radiate when the reflected wave front passes by them. You can envision another set of sources being introduces each time a new wave or reflected wave enters the picture. All these sources radiate at a strength that is a function of the surface velocity of the radiating surface. Since they all start radiating at different times and with different magnitudes, etc, what reaches a mic is the summation of all these sources at each instant in time. Over any given period of time we obtain a time continuous signal. If you change the way the sources behave, by any means, then you must change the way they radiate, and thus the time continuous signal will also change. If there is any additiona diffraction of the acoustic wave in air due to the enable patches it will also be reflected by differences in the time signal. So a direct examination of the time signal radiated from a driver before and after treatment will show the differences. It may not provide insight into exactly how the differences arose, but it will show the differences.
It has been suggested that this will not show the differences because the differences are 40 or 50 dB below the nominal levels. Taking 40dB as the threshold, -40dB is 0.01 relative to 1.0 in a linear scale. But take a look at this figure:
An externally hosted image should be here but it was not working when we last tested it.
The upper plot is the impulse response of a driver, on axis. The initial rise is to the top of the plot = 1.0. Below is the same impulse blown up by a factor of 100 vertically. Notice that just to the left of the IMP logo is a peak rising to the top of the plot which is an amplitude of 0.01 = -40dB. So clearly information at -40dB is in the time response. In fact, just to the right of that peak we can see that there is a peak at about 1/2 scale or -46dB.
I said long ago and, as usual it was dismissed. But here we are with the evidence staring us in the face. A conventional measurment will show the changes. And once we have the time response we can process it as we like, Frequency response, CSD, Burst, Step, etc. All just different ways to display the same data.
knowledge vs. speculation
Did any of the proponents ever take any college level science classes? Did they have any labs associated with them? Any engineering discipline-type courses? Any understanding of logarithmic or exponential scales, data presentation, analysis of error, etc. ? Sure doesn't seem to be evident. Just weary ongoing attempts to discredit, obfuscate, re-direct, etc.
Reason I ask is all of the data presented to support the effects of EnABL wouldn't garner a "D" on a 1st year chemistry, physics, biology lab report. Just won't pass muster... all "F's".
The only reasons I can surmise as to why reality is rejected wrt supporting claims are a total lack of understanding or knowledge of real methods to study events, or a total rejection of prior knowledge of such in favor of voodo and mystiscism.
Bud wanted me to stick around last time I left, but this is really getting sad...
John L.
Did any of the proponents ever take any college level science classes? Did they have any labs associated with them? Any engineering discipline-type courses? Any understanding of logarithmic or exponential scales, data presentation, analysis of error, etc. ? Sure doesn't seem to be evident. Just weary ongoing attempts to discredit, obfuscate, re-direct, etc.
Reason I ask is all of the data presented to support the effects of EnABL wouldn't garner a "D" on a 1st year chemistry, physics, biology lab report. Just won't pass muster... all "F's".
The only reasons I can surmise as to why reality is rejected wrt supporting claims are a total lack of understanding or knowledge of real methods to study events, or a total rejection of prior knowledge of such in favor of voodo and mystiscism.
Bud wanted me to stick around last time I left, but this is really getting sad...
John L.
Re: This is progress
I don't think it is you Ed. I think is has a lot to do with the environment. It's tough to see the light when the proponents are constantly pushing you into darkness. The idea that conventional measurements can show the differences just doesn't sit well with some. It's amazing, I think. I would image that those who are proponents of high prices cap and coils making a differences in crossovers would quickly embrace any measurement that showed any kind of difference that might even marginally be correlated with audible differences. I can hear them now, “See, I told you so." Here we have denial. "The measurements are different but it's not what I hear." Man! Audio.
Ed LaFontaine said:
I don't think it is you Ed. I think is has a lot to do with the environment. It's tough to see the light when the proponents are constantly pushing you into darkness. The idea that conventional measurements can show the differences just doesn't sit well with some. It's amazing, I think. I would image that those who are proponents of high prices cap and coils making a differences in crossovers would quickly embrace any measurement that showed any kind of difference that might even marginally be correlated with audible differences. I can hear them now, “See, I told you so." Here we have denial. "The measurements are different but it's not what I hear." Man! Audio.
Hi Ed,
'Before' testing will show difference between drivers - yes.
However reports state improvements greater than differences between two untreated (same) drivers, and the kind of 'live' testing I suggest will highlight differences as they arise so that an understanding can be gained as to what is happening; say particular frequency bands, or combinations of frequencies, or associated energy levels etc.
Cheers .......... Graham.
'Before' testing will show difference between drivers - yes.
However reports state improvements greater than differences between two untreated (same) drivers, and the kind of 'live' testing I suggest will highlight differences as they arise so that an understanding can be gained as to what is happening; say particular frequency bands, or combinations of frequencies, or associated energy levels etc.
Cheers .......... Graham.
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