KSTR said:
a man who has his priorities right - always a good sign
when you get the treatment completed, invite your buddies over for a listen
cheers
KSTR said:
I'm sure that he didn't mean that all changes can be seen on a single axis, but all changes made that impact the axis of measurement can all be seen in the before/after measurements. In the majority of cases the on-axis usually is impacted the most. It's unlikely that there will be no change on-axis, yet with significant change off-axis.
That does bring up a point on which I was planning to post. I'm sure that it's likely that no one here believes that the impact of a driver is based only on the on-axis measurement or any single axis. It takes a series of on- and off-axis measurements to yield a representative indication of the full response of a driver and therefore some correlation between measured and perceived response.
The above implication is that any drivers to be modded must have a full set of on- and off-axis measurements taken, not just on-axis, to approximate the impact of any driver treatments. Since the sound of a driver or system is the first arrival plus any room-influenced off-axis response, the off-axis measurements are also a required, especially since so much emphasis has been placed on the perception of the changes to the drivers.
Dave
Is the science ahead of us?
http://www.cbc.ca/technology/story/2008/01/11/soundwaves.html
Cloaking technology
http://www.cbc.ca/technology/story/2008/01/11/soundwaves.html
Cloaking technology
Re: Is the science ahead of us?
gee, will wavelength have any impact on this technology?
Ed LaFontaine said:
gee, will wavelength have any impact on this technology?
First long listening session ... what follows is subjective, and not blinded (even when I closed my eyes I knew what I was listening to!)
One speaker enabl'd (L) other stock (R). Published patterns for fe206e. No phase plug, and dust cap not enabl'd. No precoat and no conformal coat.
Music: varied - included Santana, Alisha's Attic, Garbage, Deacon Blue, Faure, Schubert, Zero 7, Deep Purple, Sting, Alex Harvey, Heaven 17. Familiar tracks.
Technique: normal listening position, then about 3 feet in front of a single speaker with eyes shut. Sometimes L before R, sometimes R then L, often back and forth many times. On axis and off-axis.
At first listen, nothing jumped out at me. Not sure what I expected. Very far from the sort of jaw-dropping change I experienced with eg the first T-Amp listen.
On a longer listen: no gross fr change detected. All instruments and sounds maintained normal L-R positions. Soundstage unchanged.
3 feet position revealed some consistent differences between the speakers. The enabl'd speaker sounded like the sound was coming from a speaker 2 or 3 feet behind it. This was consistent and noticable with eyes shut. Normal speaker sounded like sound was coming from the speaker. The enabl'd speaker was more difficult to locate with eyes closed.
At moderate listening levels - enab'd speaker on SOME types of music showed less background hash. This tended to be choral works and heavier guitar. Little change on undemanding music.
The enabl'd speaker also consistently displayed less beaming. This effect varied from subtle (but identifiable) to quite marked with harsher sounds.
This is a good tweak. It was well worth the couple of hours.
Anything you want me to do before I enabl the other one?
One speaker enabl'd (L) other stock (R). Published patterns for fe206e. No phase plug, and dust cap not enabl'd. No precoat and no conformal coat.
Music: varied - included Santana, Alisha's Attic, Garbage, Deacon Blue, Faure, Schubert, Zero 7, Deep Purple, Sting, Alex Harvey, Heaven 17. Familiar tracks.
Technique: normal listening position, then about 3 feet in front of a single speaker with eyes shut. Sometimes L before R, sometimes R then L, often back and forth many times. On axis and off-axis.
At first listen, nothing jumped out at me. Not sure what I expected. Very far from the sort of jaw-dropping change I experienced with eg the first T-Amp listen.
On a longer listen: no gross fr change detected. All instruments and sounds maintained normal L-R positions. Soundstage unchanged.
3 feet position revealed some consistent differences between the speakers. The enabl'd speaker sounded like the sound was coming from a speaker 2 or 3 feet behind it. This was consistent and noticable with eyes shut. Normal speaker sounded like sound was coming from the speaker. The enabl'd speaker was more difficult to locate with eyes closed.
At moderate listening levels - enab'd speaker on SOME types of music showed less background hash. This tended to be choral works and heavier guitar. Little change on undemanding music.
The enabl'd speaker also consistently displayed less beaming. This effect varied from subtle (but identifiable) to quite marked with harsher sounds.
This is a good tweak. It was well worth the couple of hours.
Anything you want me to do before I enabl the other one?
chrisb - Ed
Here's a little lite reading for ya. http://www.ee.duke.edu/~cummer/reprints/061_cummer07_njp_acousticcloaking.pdf Back when I used to work for a living we used a lot of Dr. Cummer's research in Ionospheric Sounding Systems to support Over the Horizon Backscatter Radar and some communications systems. Not that I know enough about them to fill up a shot glass of knowledge - we were merely the technicians that kept the systems running and did field support - not the PHd's that dreamed 'em up nor the engineers that designed them. 😀
Here's a little lite reading for ya. http://www.ee.duke.edu/~cummer/reprints/061_cummer07_njp_acousticcloaking.pdf Back when I used to work for a living we used a lot of Dr. Cummer's research in Ionospheric Sounding Systems to support Over the Horizon Backscatter Radar and some communications systems. Not that I know enough about them to fill up a shot glass of knowledge - we were merely the technicians that kept the systems running and did field support - not the PHd's that dreamed 'em up nor the engineers that designed them. 😀
chrisb said:
We have my second cousin staying with us. She confirmed the single speaker effects - without any prompting from me. Her comment was that the enabl'd speaker sounded better, and the sound seemed to come around rather than from the speaker.
She has 20yr old ears (mine are 48 but holding up reasonably well).
Hi Alan,
Great to hear (no pun intended) of your level 1 tweak. I'm sure that BudP will have some advice about putting on some conformal coating as well as a pattern for the dust cap or phase plug when you get around to them - and trust me - you will be getting around to them (and I mean that in a good way!)..... Enjoy! 😀
Oh - BTW - add a bit of Pink Floyd "Dark Side of the Moon" and listen to the background voices.
Great to hear (no pun intended) of your level 1 tweak. I'm sure that BudP will have some advice about putting on some conformal coating as well as a pattern for the dust cap or phase plug when you get around to them - and trust me - you will be getting around to them (and I mean that in a good way!)..... Enjoy! 😀
Oh - BTW - add a bit of Pink Floyd "Dark Side of the Moon" and listen to the background voices.
Both speakers enabl'd now. Long, low-level listen (it's late): Brahms (German Requiem), Queen, K D Lang, More Sting and Santana, Paul Simon.
Across the board, fine details easily heard and very natural and relaxed sounding - some sort of hazy distortion has gone. Must be measurable!
Gentlemen, this is no humbug!
Across the board, fine details easily heard and very natural and relaxed sounding - some sort of hazy distortion has gone. Must be measurable!
Gentlemen, this is no humbug!
I sure don't doubt it. Too late to do some polished writing (er, them beers)... but I want to link to a nice site showing the two types of waves (and as such, decomposed parts of standing waves pattern to which they combine) of cone movement as well as inside the cone:Alan Hope said:
http://physics-animations.com/Physics/English/wav_txt.htm
Imagine those diagrams as a cross section of piece of the cone, dont take them as the actual standing wave pattern but as individual travelling waves superposing with each other to form the "standing" amplitude (of displacement) patterns of either the cone (transversal) and movement inside of the cone itself (longitudinal), resp.
The transversal stuff is obvious and the little added mass will not change much of it...
Intuition tells me as of now (give me time to elaborate on this later, maybe) that it might be the longitudinal stuff which is apparently mostly changed with enABLe. The reflection of the longitudinal travelling waves is the key point, enABLing seems to scatter it. Given the perfect circular symmetric geometry of the typical driver it is then obvious that scattering would do the same good thing that diffusors do to a circular or even spherical room energized in a likewise symmetrical fashion: remove/reduce the bouncing discreet echos and turn them into diffuse reverb. This assumes that some of the longitudinal stuff gets "shifted" back into the transversal domain to have significant effect on the acoustic output -- I strongly suspect such coupling to take place (also vice versa, but to a lesser extend maybe, while the main impact comes from transient VC movement to trigger the longitudinal waves -- it seems I begin to understand what Bud means with transitional standing waves, somewhat different to those more steady-state transversal issues with respect to the time scale).
Enough rambling...so, is there anything to it? And if so, wouldn't a more "random" pattern do even better?
- Klaus
EDIT: lots of typos
Klaus,
My own 'intuitions' concur with yours. My little experiments on an EX3, a while back, were premised on breaking - symmetry of the cone and whizzer termination.
Cilla
My own 'intuitions' concur with yours. My little experiments on an EX3, a while back, were premised on breaking - symmetry of the cone and whizzer termination.
Cilla
Klaus,
Add the fourth dimension to the three you are working with, two dimensions plus time, as you think. Everything that is traversing across these surfaces is also emitting energy out into the longitudinal wave. If it is more efficient for this energy to emit into the longitudinal wave, than for it to ring in some form of standing wave, then that is what will occur.
In addition, these transverse waves are being fed from the interior of the cone. This occurs across the entire surface of the cone, almost regardless of amplitude, but not regardless of frequency. This is going to make for some very complex interactions at different positions in the boundary layer. This is what the conformal coating is intended to address and what Soonsgc's additional ring set, also appears to address.
The importance of the boundary layer and controlling what is allowed to occur, within this easily disturbed volume, is just the tool I am using to effect a change in the conditions surrounding the transform of energy into the eventual compression wave.
As for randomness, what investigations I have done, without any regard for scientific rigor, didn't show an audible benefit over the current pattern, if it is a randomness spread across the entire cone surface. Random dots within a band were interesting but not effective in revealing the low level coherence that the current pattern will. They did affect the perception of localization to a driver as a source, as effectively as the current pattern does.
I am going to explore the pattern described in a recent post in about three weeks, along with learning some more about how to bring whizzer cones under control.
Ronc recently brought up a scenario where a pattern of increasing height with increasing distance from the center of the emitter, would be able to perform what EnABL appears to do. I am pretty sure that applying an EnABL pattern in the boundary layer and then making the boundary layer more effective and less diffuse, is providing much of what he spoke of.
Bud
Add the fourth dimension to the three you are working with, two dimensions plus time, as you think. Everything that is traversing across these surfaces is also emitting energy out into the longitudinal wave. If it is more efficient for this energy to emit into the longitudinal wave, than for it to ring in some form of standing wave, then that is what will occur.
In addition, these transverse waves are being fed from the interior of the cone. This occurs across the entire surface of the cone, almost regardless of amplitude, but not regardless of frequency. This is going to make for some very complex interactions at different positions in the boundary layer. This is what the conformal coating is intended to address and what Soonsgc's additional ring set, also appears to address.
The importance of the boundary layer and controlling what is allowed to occur, within this easily disturbed volume, is just the tool I am using to effect a change in the conditions surrounding the transform of energy into the eventual compression wave.
As for randomness, what investigations I have done, without any regard for scientific rigor, didn't show an audible benefit over the current pattern, if it is a randomness spread across the entire cone surface. Random dots within a band were interesting but not effective in revealing the low level coherence that the current pattern will. They did affect the perception of localization to a driver as a source, as effectively as the current pattern does.
I am going to explore the pattern described in a recent post in about three weeks, along with learning some more about how to bring whizzer cones under control.
Ronc recently brought up a scenario where a pattern of increasing height with increasing distance from the center of the emitter, would be able to perform what EnABL appears to do. I am pretty sure that applying an EnABL pattern in the boundary layer and then making the boundary layer more effective and less diffuse, is providing much of what he spoke of.
Bud
Hi Klaus -
Some ripple tank simulations showing a pulse response echo without any pattern and with a random pattern applied near the edge of the circle. Note that this is a pulse response and not frequency response - plotting frequency response and diffusion isn't something I can do with the ripple tank simulator with any degree of accuracy. Green is the pulse being xmitted by the VC - red is the echo return from the edge. For a pulse it seems that a non-repetitive pattern would serve to diffuse the pulse - but how it would work with different frequencies at different amplitudes starts to get a bit sticky wicket. It is something to consider - and as BudP has stated - he is working on things.
Some ripple tank simulations showing a pulse response echo without any pattern and with a random pattern applied near the edge of the circle. Note that this is a pulse response and not frequency response - plotting frequency response and diffusion isn't something I can do with the ripple tank simulator with any degree of accuracy. Green is the pulse being xmitted by the VC - red is the echo return from the edge. For a pulse it seems that a non-repetitive pattern would serve to diffuse the pulse - but how it would work with different frequencies at different amplitudes starts to get a bit sticky wicket. It is something to consider - and as BudP has stated - he is working on things.
Attachments
Just a few comments on technique. The process - esp under the whizzer is quite demanding.
Despite a fair bit of practice, I gave up on the nibs. I couldn't get them work well - for me - with acrylic paint. In practice I got more consistent 'slightly rounded rectangles' using a fine sable brush. I used a larger sable for the outer rectangles which would do two rectangles with a single charge - one stroke, twist brush, second stroke. Then a very fine sable for the interiors of the whizzer and cone. You are really talking dots here.
I'll do some pics and put up a web page showing how I marked things out, and how I used a metal ruler to support the brush under the whizzer.
Despite a fair bit of practice, I gave up on the nibs. I couldn't get them work well - for me - with acrylic paint. In practice I got more consistent 'slightly rounded rectangles' using a fine sable brush. I used a larger sable for the outer rectangles which would do two rectangles with a single charge - one stroke, twist brush, second stroke. Then a very fine sable for the interiors of the whizzer and cone. You are really talking dots here.
I'll do some pics and put up a web page showing how I marked things out, and how I used a metal ruler to support the brush under the whizzer.
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