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Old 3rd July 2011, 05:00 PM   #1021
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Dear Bud & others,

I am NOT talking about doing the usual method(s) for the EnABle process, I am talking about exagerrating dramatically one or more of the parameters to make CLEAR the effect(s).

Parameters =
- size
- number
- mass
- material
- etc...

Things like that... use some lead strips for example, and SEE that the addition of significant small masses will have.

Use LARGE strips of high mass, and see what that does.

Clearly it will be excessive, but it will SHOW something CLEARLY about what mechanisms are being effected and what directions they go in...

Dunno, seems like an idea?

(I read a few pages back... that's not what I am suggesting in terms of tests)
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Old 3rd July 2011, 05:23 PM   #1022
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Lots of (unfounded) assumptions in your proposal. Confounding could occur if the supposed effect is not mass related, or size related (or a combination of both), or if the positioning is highly sensitve... it's not simple to determine whether a cause/effect relationship exists here... hence the opposition to hand-waving "boundary layer" effects that remain unproven (or even clearly demonstrated)

John L.
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Old 3rd July 2011, 06:01 PM   #1023
dlr is offline dlr  United States
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Quote:
Originally Posted by bear View Post
Dear Bud & others,

I am NOT talking about doing the usual method(s) for the EnABle process, I am talking about exagerrating dramatically one or more of the parameters to make CLEAR the effect(s).
For that to work one has to have the ability to adequately measure the parameter or determine it and provide proof in some manner. The concepts and effects hypothesized are not those which most have the capability to measure. That's the crux of the problem to begin with. If we could measure them, there would be no debate. I seriously doubt that anyone who frequents this board can measure the boundary layer or most other of the effects described, even less so that of a dynamic driver.

We can, however, easily measure parameters on which the change does have known impact, things such as T/S parameters, any and all derived responses from an impulse such as SPL, phase, step, etc., that would have to be taken on a polar basis. And if one cared to take the time, do a lengthy set of various distortion measurements. These are the effects that actually matter. Without these or some other valid set of measurements, anything postulated outside of these well-known effects is just making an unsubstantiated hypothesis. Subjective listening and hypothesizing is not proof of anything.

Google "boundary layer measurements". This link is from a Cal State wind tunnel test and is just one paper you might find. Consider the difficulty and required resources described in that one alone.

Simplistic testing won't prove anything.

Dave
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Old 3rd July 2011, 10:08 PM   #1024
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Dave is certainly correct Bear, we just don't have easy access to the equipment required.

We do have some results from tests done on "extreme" pattern applications from the original thread,

EnABL Processes multiple rings and phase vs frequency response

EnABL Processes dispersal of "break up modes" and resonance nodes

EnABL Processes large blocks and dots applied

These may help you in refining your suggestions.

Bud
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Old 3rd July 2011, 10:29 PM   #1025
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I'm not sure if I understand what Bear is getting at. Added mass is pretty well understood and just about anyone with a Woofer Tester uses added mass as a matter of procedure when measuring. I know that years ago, on the old "Bass List" there were experiments of this nature. I believe that there were some alterations in the "Q" of the DUT, but not much else that remotely resembles what Bud has related pertaining to the EnAble method.

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Old 4th July 2011, 12:17 AM   #1026
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Terry,

yeah.

Added mass is usually at the center near the VC and behind the dustcap... not out on the "rings of saturn".

John L. I agree. Not so simple or easy. First pass is to rule in or out very simple effects...

Bud, I will try to take some time to look at the links you put up...

Fwiw, there was a speaker "back in the day" by University that had a mechanical xover built into the cone. I guess it was some sort of compliance ring, I am not clear on it actually, but I suppose it could move a bit at HF and not much at LF, so the woofer worked out the edge at LF. Not sure, but they did do this sort of thing... it seems conceptually related, even if removed by some degree...

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Old 5th July 2011, 10:28 PM   #1027
sreten is offline sreten  United Kingdom
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Hi bear,

FWIW you can roll-off a driver by adding mass directly to the voice coil.
Tannoy for one used to do this in their 2.5 way designs, a lump of plastic
instead of the dustcap for the lower 0.5 way driver, saves on the c/o,
as it avoids the need for a large inductor.

rgds, sreten.
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Old 5th July 2011, 10:53 PM   #1028
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sreten, of course, but this has little or nothing to do with what we are talking about...

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Old 5th July 2011, 11:29 PM   #1029
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Default Huh??

Quote:
Originally Posted by bear View Post
sreten, of course, but this has little or nothing to do with what we are talking about...

_-_-bear
What exactly ARE we talking about? Somehow trying to prove that some folks have imaginary friends? Of course they do, why bother??? But none of the rest of us can share those friends, for they are only real to those who experience them!!

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Old 5th July 2011, 11:40 PM   #1030
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John, after all these years, do you have to still go off like that??

Put another way, can you read what was written in the context that it was written?

Let me diagram it out for you:

- EnAble consists of little tiny thingies applied in a pattern out on the cone (mostly)
- People argue about this and that, and if and how it works
- I say, let's not use this technique as a subtle modification, let's hit it (more or less) like a sledge hammer and see a bit more clearly what the first order effect(s) may be?
- sreten talks about putting mass at the cone/vc junction.
- I say what does that have to do with it? (we're not at the cone/vc junction, eh? and we're not using a single mass, eh?)

What you are yammering on about is some theoretical argument that I am not party to, that and measuring everything properly and accurately - which is fine, go and measure, I have no problem with that. I have no theory espoused on this technique, and no data to share, only the suggested means to possibly increase the effect to the point where it is unambiguous.

Do you have a problem with that?
Did I miss something important here?

Who is "we"?

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