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-   -   EnABL - Technical discussion (http://www.diyaudio.com/forums/multi-way/119677-enabl-technical-discussion.html)

Cal Weldon 18th March 2008 10:32 PM

EnABL - Technical discussion
 
This thread is a continuation of the EnABL Processes Thread here:
http://www.diyaudio.com/forums/showt...5&pagenumber=1

This thread is for the objective side of things. If you wish to post your listening impression, please post them here:

http://www.diyaudio.com/forums/showt...hreadid=119676

moray james 18th March 2008 10:42 PM

hello
 
nt

BudP 18th March 2008 11:08 PM

Hi All.

Just want to start things off correctly here, and post my idiot thoughts.

I am and have been in agreement with John K's description of a drivers fundamental activity, as described by classical physics. Have been since I thought my way through Lincoln Walsh's patents and Beranek's short sector on diaphragms in "Acoustics"(page 199 through 201) sometime in the late 70's.

What has always given me grief, is that for the various parts of an EnABL'd driver to enforce the rather drastic sounding changes they do, even that model seemed inadequate. I mean really, how can a pattern in the first few tenths of an inch provide enough of a control over what the ongoing transverse wave emits, into the air purely by displacement, to enforce actions beyond the pattern? It makes no sense.

And then, how do the two, and now three, sets of pattern blocks accomplish this EnABL effect, upon different portions of the time train of a musical note, from a discrete instrument, like a piano. All of a piano note is certainly not on the driver surface all at once, none of it is on for very long and yet the typical corruptions, that do occur from a purely displacement event driver, are erased to a degree substantial enough to "trick" the ear / correlators/ mind, into locking onto only the corrected signal.

This seeming impossibility is why I have been so tenacious in putting forth some sort of additional effect, in my usual techno babble, head ache inducing form.

Bud

auplater 18th March 2008 11:30 PM

it's not due to boundary layer effects
 
My knowledge of boundary layers implies there is a mass transport phenomena occurring. That is, eg., at a solid to liquid interface, where a change is occurring, the properties by definition transition from those describing the bulk solid to those describing the bulk liquid (or gas-to-liquid, etc.). The area in between has a gradient from the one form to the other, a flux, of the material in transition, be it airflow over an airfoil, sulfur dioxide to sulfur trioxide on a lead dioxide catalyst to make sulfuric acid, iron to iron oxide on a car bumper, etc, all governed by Fick's laws of diffusion, Reynold's #'s etc.

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. Furthermore, if somehow some sort of application of boundary layer kinetics were to be attempted, theory would seem to predict that any projection of significant height within the area of such application would make a simple situation more complex, not the reverse.

John L.

soongsc 18th March 2008 11:49 PM

Quite interesting how this thread keeps expanding.

Saturnus 19th March 2008 12:03 AM

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

Originally posted by auplater
Furthermore, if somehow some sort of application of boundary layer kinetics were to be attempted, theory would seem to predict that any projection of significant height within the area of such application would make a simple situation more complex, not the reverse.

That is indeed what I think is the core here. That extra distortion is added by the process but that that distortion to some people is more "natural" or "melodic". That would indeed also explain the perceived higher output of treated drivers.

Very similar to tube amps vs. other amps discussions, few can argue that empirically tube amps are inferior but yet many people insist on using them for their "natural" or "warm" sound.

BudP 19th March 2008 12:09 AM

auplater,

Quote:

Furthermore, if somehow some sort of application of boundary layer kinetics were to be attempted, theory would seem to predict that any projection of significant height within the area of such application would make a simple situation more complex, not the reverse.
That is certainly in agreement with what John K has been providing. I would point to the strange and unscientific wave tank results for an additional confusing element. Not, as was assumed, so much because a Soliton wave is rolling across the cone surface, as some sort of enforced circular energy transform mechanism, but as a pointer to what sort of organization the patterns do appear to enforce upon passing wave structures. This sort of activity would allow for an after the fact control of emissions, but seemingly to me, only in a form of boundary layer gradient.

Certainly does not mean either are actually in play, but some equivalent activity, that does control that pressure transfer gradient, between deep mesh structure, passing transverse wave and the adjacent air seems waranted.

I do like dlr's comments upon trapped transverse waves ringing to extinction between final pattern and surround or cone edge, but I have real difficulty in understanding how that pattern, with it's locally huge mass differential, but overall mass to mesh mass ratio, can accomplish this event. Unless there is some hidden factor in the importance of the local mass ratio and pattern structure.

You know, the secret sauce thingy.

Bud

BudP 19th March 2008 12:22 AM

Saturnus ,

I agree, it could be something of the sort. Certainly the difference in odd to even distortion ratio's found in the two different amplifier types has a large bearing upon what a person likes and dislikes.

The EnABL patterns may be doing something similar, but the only distortion tests done so far, by me, don't show that sort of help. To the contrary in fact, just as John K pointed to.

Also it does not seem to be quite as closely tied to personal experience and preferences, at least in the ad hoc A/B testing done to date. SY has indicated he is closing in on control of the tools needed to perform some objective quantifications, of drivers he is interested in. He also plans to run a double blind test with those same drivers. Perhaps even one that conforms to John l's trusted ANOVO procedures.

RonC is poking at some A/B drivers with a laser interferometry tool and RAW plans an extensive set of tests on a six piece spread of a specific driver. All to be posted and discussed here. So, data is on the way.

Bud

Saturnus 19th March 2008 12:36 AM

And it shall indeed be interesting to see.

What physically happens is hard to make educated guess about without. There has been many suggestions in the original thread, and many of them could be the reason. Either on their own or in a complex combination of different phenomenii.

My best guess is that it adds a form of controlled distortion while at the same time dampening random distortion. Much like dither and jitter in digital circuits where you try to reduce random distortion, jitter, as much as possible, and in many highly acclaimed circuits add controlled distortion in the form of dither.

auplater 19th March 2008 12:38 AM

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

Originally posted by Saturnus


That is indeed what I think is the core here. That extra distortion is added by the process but that that distortion to some people is more "natural" or "melodic". That would indeed also explain the perceived higher output of treated drivers.

Very similar to tube amps vs. other amps discussions, few can argue that empirically tube amps are inferior but yet many people insist on using them for their "natural" or "warm" sound.

This hints at something that occurred to me and why I keep mentioning confounding and statistical methods. There could be codependent variables acting; if one were to postulate, for instance, a perception or expectation variable, that confounds with a distortion variable, that yields the overall response of "I like that better" or "that sucks".

One efficient way to find that out is a statistical design with known distortion components at different levels that are expected to influence the sound (maybe planet10's -40dB signal), set up with enough trials and treatment levels to be significant across the second cofounded variable of perception and expectation (find volunteers who are believers and others who are skeptics, have them listen and score, for example) then do the analysis to decide the null or alternative is correct.

John L.


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