EnABL - Technical discussion

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Carlp said:
dlr,

I'm pretty sure I heard John K to be talking strictly about the effect of EnABL on the movement of the cone surface and what that does to sound. I'm talking about what that cone surface movement does to the air above it and what effect EnABL might have on that air movement - and hence on the sound.

So did I miss what he was saying? If so, can someone please explain in more lay terms? I've read that thread several times and it obviously hasn't sunk in. Too much thinking on my part no doubt... :confused:

Carl

John's point was to say that enabl does not make any significant impact on the boundary layer of a driver. Despite the acronym created and as he pointed out, the boundary layer remains, it simply is moved to the new position at the surface of the treatment. It is not enhanced nor "lifted off" of the surface. John delved into the theory and based his analysis of driver diaphragms from the scientific study he undertook. He also made before/after measurements of a driver that he treated himself. Bud's claims about boundary layer enhancement are without merit. He really ought to call it something else, because the changes one may hear with a treated driver are not due to boundary layer changes, certainly not some undefined and undefinable enhancement as posited by Bud. Changes are fully consistent with mass/damping effects. As I've said before, it's a perfect example of Occam's Razor, especially paragraph 3.

Thinking of it, I would suggest calling it the Morse Code Treatment, as in dots-n-dashes. That is closer to reality.

Bud was also claiming that changes were heard even if no change in frequency response occurred, a complete fallacy. I'm sure John is loathe to get back into that discussion. His tests were definitive, some just refuse to accept facts and prefer to continue with fantasy.

Dave
 
acronym-itis

Boundary layer concepts (as stated earlier in this thread) apply to net flow mass transfer effects between a viscid fluid and a surface in vicinity of that surface, that is delta(m)/delta(x)

Since there is no net flow of any mass in this situation, enabl as an acronym is a misnomer, a misunderstanding of the fundamental concept of boundary layer..,.

http://www.grc.nasa.gov/WWW/K-12/airplane/boundlay.html

Even if one tries to apply the concept to perpendicular motion, the wavelengths involved (as well as the boundary conditions) preclude any effect whatsoever attributable to the miniscule patterns applied... i.e., the boundary layer would completely swamp out any local effects by the time said effects (if they even exist) propagated through the alledged layer (if it even exists).
 
ripple stuff

Geez... I'm sorry... I thought we were talking about alledged audible effects and causality of enabl/morse dots, not visual effects...

In that case i suppose the ripple tank simm has some merit in that the expectation of visualization has a profound effect on the perception of audibility by subjects in sighted comparisons and demonstrations... :D :bigeyes:
 
Boundary layer concepts (as stated earlier in this thread) apply to net flow mass transfer effects between a viscid fluid and a surface in vicinity of that surface, that is delta(m)/delta(x)

Auplater,

Thanks for the simple explanation :smash: . So I can get it through my thick head, are some saying that, taking into account the viscosity and compressibility of air (both of which I would think are quite high relative to, say, water), such physical disruptions as presented by the enabl pattern within the boundary layer wouldn't impact the sound wave in free air (beyond the boundary layer)? It just doesn't jibe with my ocean kayaking experience (on water, of course), hence my skepticism.

If I think about boundary layer effects on an airplane wing, I'd say stall is a pretty significant impact, further confusing me.

Carl
 
bound to be... or not

Carlp said:


Auplater,

Thanks for the simple explanation :smash: . So I can get it through my thick head, are some saying that, taking into account the viscosity and compressibility of air (both of which I would think are quite high relative to, say, water), such physical disruptions as presented by the enabl pattern within the boundary layer wouldn't impact the sound wave in free air (beyond the boundary layer)? It just doesn't jibe with my ocean kayaking experience (on water, of course), hence my skepticism.


Viscosity of air relative to water would be low....

What mechanism do you propose for the existance of a significant boundary layer at all? there is no net delta(m)/delta(x)... unlike an airplane (or kayak) in motion... :cannotbe:

Carlp said:

If I think about boundary layer effects on an airplane wing, I'd say stall is a pretty significant impact, further confusing me.

Carl

see above re: existance of a significant boundary layer
 
Carlp said:
<snip>

So I can get it through my thick head, are some saying that, taking into account the viscosity and compressibility of air (both of which I would think are quite high relative to, say, water), such physical disruptions as presented by the enabl pattern within the boundary layer wouldn't impact the sound wave in free air (beyond the boundary layer)?

If I think about boundary layer effects on an airplane wing, I'd say stall is a pretty significant impact, further confusing me.

Carl

guess I just misinterpreted what you meant here...
 
guess I just misinterpreted what you meant here...

No, yours was a reasonable interpretation. I just hadn't intended any interpretation of boundary layer as I hadn't considered the question of the magnitude of the BL yet. Nonetheless, there is presumably SOME impact, but the magnitude of the impact hinges on the magnitude of the boundary layer.(?) I don't have the ability to calculate or envision BL, but I have a much better sense of what we're talking about now, thanks.

Carl
 
Carlp said:


No, yours was a reasonable interpretation. I just hadn't intended any interpretation of boundary layer as I hadn't considered the question of the magnitude of the BL yet. Nonetheless, there is presumably SOME impact, but the magnitude of the impact hinges on the magnitude of the boundary layer.(?) I don't have the ability to calculate or envision BL, but I have a much better sense of what we're talking about now, thanks.

Carl

I believe that John k got a reference on the theory and worked through it in his study and determination that it is inconsequential on a driver. He may respond to a PM, I doubt that he'll weigh in further here.

Dave
 
Re: it's not due to boundary layer effects

auplater said:
My knowledge of boundary layers implies there is a mass transport phenomena occurring. ...
CUT...
I can't envision how a vibrating speaker cone producing an acoustic output (via trasverse waves, surface waves, planar waves etc.) involves any net mass transport across the energy interface, hence the conditions to develop a boundary layer don't exist. ...
CUT...

John L.

Hello all,

(beg your pardon for my poor english)

anything moving, like water flowing out of tap, or loudspeaker membrane moving in & out, produces LOTS of ions who are either moving eratically or quickly recombined, so this is where we have a mass transport

POL
 
grasping at straws here

pol_bct said:


Hello all,

(beg your pardon for my poor english)

anything moving, like water flowing out of tap, or loudspeaker membrane moving in & out, produces LOTS of ions who are either moving eratically or quickly recombined, so this is where we have a mass transport

POL

moving speakers (other than ESL's, etc.) producing ionization??? maybe put that out for a Nobel prize in physics... the energies just aren't there (by orders of magnitude)

whatever your source of information here is, it flies in the face of decades of R&D on boundary phenomenon.... but whatever... this entire thread is pontless anyway...

John L.
 
nope

pol_bct said:
Hi auplater

I did not talk about hi voltage ionization
I said ANYTHING moving produces lots of ions
when you spin your CD on, walk on the floor, and so on...

If moving water produced ionization, we wouldn't have had to supply a charge to deflect ink-jet drops for continuous printing, back when I worked for Kodak making inkjet printers....

so your hypothesis about continuous ionization "doesn't hold water"... so to speak... :D

besides, if you read earlier posts, there needs to be a net delta m/delta (x,y,z) for a boundary layer to setup and have any effect on the macro scale (as in what you hear)... not to mention the proposed perturbations need to be significant wrt the wavelengths involved and/or bl dimensions (which they aren't)

might want to read up on band theory in solids... google can be your friend hear... Ficks law of diffusion may also enlighten...

http://en.wikipedia.org/wiki/Fick's_law_of_diffusion

"ions" has a specific meaning... band theory of materials can help clarify
 

Attachments

  • enabl posts for treatment text file.txt
    5.4 KB · Views: 54
I don't know. I have a contact who is beginning production, one at a time, of violins, guitar and cello's after having used the EnABL patterns to find and manipulate resonance nodes, on the sounding boards. He says the patterns wander all over the board and that he has begun to shift his support structures to quell some of the resonances and enhance others. I do not think he plans to use the patterns on finished instruments, but does seem to find the methods to be useful.

As for this particular usage, maybe, maybe not. I would apply a pattern around the outer perimeter first, as was done recently and spoken of here

http://www.diyaudio.com/forums/planars-exotics/153458-enabl-esl-quad-speakers.html

I am not at all sure how closely a Maggie mimics the bending board driver concept, but all they needed was edge control on the decorative side pieces to eliminate their audible problems.

Bud
 
Hi there Bud. Just discovered this rather mammoth collection of threads. What interesting reading! Congrats on your "coming out of the woodwork" with it. I have spent a couple of nights wading through page after page of posts in the original thread, only to find that there are more threads.
One thing I have noticed is that although this started out in the "multi-way" speaker forum, it seemed to move over to discussions involving full range drivers and very little else. I have been looking for info about "enabl"ing conventional drivers with very little success. I have Scanspeak 3 ways I built about 10 years ago and have recently got stuck into experimenting with different crossover designs and components. (Your standard "can of worms" type activity) Enabl seems like it might be really great for what I am trying to achieve (primarily, absolute transparency). I keep hearing possibilities that I am struggling to realize. Have you tried it on similar units and what were your findings? My drivers are 21w8555 (paper 8"); 18w 8545k (paper/carbon 7"); d9205-9700 (silk dome tweeter). Perhaps you know of specific posts that may be helpful. (I have tried a few searches with no success.)
 
Disabled Account
Joined 2004
Hi All,

The resonance movies on U Tube have been moved to storage. Here are the URL's for 1 through 4.

YouTube - resonance
YouTube - resonance2
YouTube - resonance4
YouTube - resonance3

Attached is a revised copy of the EnABL locations document.

Bud

Thanks for these. I don't think the potential electro-static effects of all the moving powder particles is dealt with (might not matter). Hans Jenny was a big fan of Rudolf Steiner even dedicated his major book to him.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.