Digression from EnABL techniques

[dlr]

Originally posted by BudP The Beta 8 requires some back side patterns to quell a strong Rlaeigh wave, circulating in the outer third of the cone. The Delta 8 does not have this problem.

Please go over to the technical thread and explain how you determined that there are Rayleigh waves and that these are in fact the mechanism being addressed, especially the part about how they travel around the outer third, in the perimeter of the cone. Describe the experiments and measurements you took that provide the data that supports this. Please add in why they do not occur in the other inner areas.

I know that no one here wants to discuss the technical aspect, but the claim has been made here. Since there is a thread specifically for this, it would be appropriate to elucidate there, not here.

Dave

[dlr]

Originally posted by dviswa
dlr, please go away. There is another thread set aside for people like you and please keep this thread for us people who are interested in learning and who have no desire for a p@*&#*g contest.

Mods, if this was out of line, nettiquette wise, please cut off thye top portion up till here of this post.

Yes, I think that your post is out of line. Somehow you missed where I specifically directed attention to the other thread and pointed out that it is the appropriate place, not here, even though Bud, not I, raised the technical aspect in this thread. I only asked that he move to that thread. This is pretty much in agreement with your position, although I was polite in my post. You took me to task rather than Bud, even though his post had the technical comments. Why do you berate me, but not him?

Dave

[dlr]

Since this has morphed into the "technical" again and I would like to comment on this most recent post, lest I be thrown out for introducing the technical as Bud has done in detail, I ask the moderators to move this post over to the technical thread for debate. As many are so vehement to say when I broach the technical, it's not to be debated here.

Or will there be consistency and I be allowed to discuss it here as Bud did?

I also really think that mention of comprehension should not be broached, lest that devolve into more controversy. Bud, you speak as if the entire origin thread and the partner objective one to this one never occurred.

Dave

[dlr]

Originally posted by LilMik


sorry, but this is nonsens.

actually, i am a "believer", i have already enabled a few drivers myself and i know it "works", at least most of the time the driver sounds better, for whatever reason. but... come on, you are telling that it makes a difference in bass performance if i paint a little bit micro gloss over an enabl patter that is painted on a port? no, please, don't tell me: just try it, not this time. please, think about what you are saying.

BudP, if you are reading this, can you tell me your honest thought's, please. thank you very much in advance.

sincerely,
mike

Here is a link to the split of the original thread that is supposed to be where any and all "technical" discussion occurs. There's a link there to the first thread.

Technical thread

You'll find a lot of answers to your questions in those two and far more detailed descriptions of what is and is not occurring. The detailed technical aspect is supposed to be forbidden here.

Dave

[BudP]

Dave,

Actually I was just answering Mikes plea. As for not broaching comprehension, that is the very reason I answered here. The points I am making are entirely within the realm of comprehension, as opposed to a more objective approach.

I really am not ignoring you, or any of the others involved in threads working on figuring out how EnABL accomplishes it's activities. I just do not have much more to provide for the objective side.

Bud

[dlr]

"entirely within the realm of comprehension, as opposed to a more objective approach". So you're saying that the objective approach is not comprehensible? It does at least have to start with technical merit.

The points you were making are certainly counter to just about everything as debated in the technical thread. This comment alone is, to be blunt, incredulous:

Since it is now fairly obvious that the pattern does not affect the activity of a diaphragm, all that is left is that it eliminates the nonuniform transformation of energy, from the diaphragm into the air.

Fairly obvious? What's your source or support for this claim? The ONLY thing that is affected is the "activity" of the diaphragm. There is no effect of propogation in air outside of the localized effect as was discussed in great detail before and is pretty much an added mass effect. Change yes, esoteric, no. Only on a moving component such as a diaphragm, nothing on vents, nothing on baffles.

You say that you have little more to provide to the objective side, yet the post is filled with "objective" technical misinformation based on nothing but, again, conjecture that has been shown to be in error.

And as far as the link to youtube, it's beyond me how you can make any sort of association of that with enabl. There is no logical inference that is credible.

Then there is "relieved of their last nonlinear transformation of energy into adjacent air". Sounds pretty technically objective to me, but there's nothing to support this conjecture, either.

"EnABL'd drivers do appear...", "If diaphragms will exhibit...", "...EnABL seems to correct for...". Really, Bud, there's nothing of substance in most of this. It says nothing about what is actually happening and claims things that are just not correct.

Enabl will change how a driver sounds. It may be an improvement, it may not be. There are never guarantees. But it has nothing to do with any of the continuing esoteric claims. It's an added mass and/or localized damping effect. This is a prime example were Occam's Razor applies. I'm sure that you're familiar with that.

Dave

[dlr]

Originally posted by BudP
The sonic impact is the same for tweeters, mids, woofers, full range etc. The silk dome tweeters are usually VERY finicky about the amount of gloss you apply. No more than one 50% gloss / 50% water coating, or their efficiency will rise rather abruptly. Or, perhaps it is just the phase response that changes? In any event you usually end up taking any more than one coating of Gloss back off.

Basic pattern is as shown here

http://picasaweb.google.com/hpurvine...53144724871474

You can put a pattern on the inside of the dome, just above the voice coil joint if you are brave and have taken these things apart before.
Also best to use a Rapidiograph technical pen on the silk, the sharp points of the 66 pen tip may just slide right through.

Bud

Do you have any factual data to support increased "efficiency" (I think that you mean sensitivity)? Any time that you add weight to a driver, it will almost invariably reduce the sensitivity. It's basic physics. The phase response change will also be strictly according to any change in frequency response.

A good soft dome such as those by Seas are also not likely to be improved by randomly adding weight, especially near the surround. It's more likely to be detrimental. I find it rather troubling that you would suggest this to someone who may end up with a damaged tweeter.

If you can provide any measurements whatsoever of a soft dome before/after that documents an improved response, I'll retract my concern.

My suggestion, leave that Seas dome alone, unless you're ready to lay out the money to replace them if it doesn't work as advertised. Seas is one of the best at making excellent soft domes.

Dave

[BudP]

dlr

Your concern is noted and appreciated Dave. However, there is a history behind my treatment suggestions, considerably deeper than the one from full range drivers, that you may, by now, be experienced with.

Once again we are confronted with a lack of significant change found in what objective testing I have performed over the last 20 years or so. The treated tweeters, just as with the full range devices, exhibit a great deal more information in the audible signal, that is substantially below that of the first arrival / loudest impulse in amplitude, than the untreated drivers.

I am sure by now that the data is actually in the tests, but have no way to manipulate it to discover data that corresponds with changes that are audible well below that signal portrayed in all of my testing. This data would have to show relationships between low level signals and maximum signal level impulses.

I do also suspect that if we could graph these changes they would be very simillar to what John K found in his test and provided as a roll on roll off mouse controlled flick comparison.

As for the mass increase, the dots themselves are so small and so thin that they will not provide appreciable mass change. The Gloss coating is another matter and beyond one light coating, will stiffen the silk cloth substantially.

As always, the driver should be monitored for the effects of the pattern, before application of the Gloss material. All but one of the silk drivers I have dealt with were aided, and all plastic domes and metal domes have been aided, by Gloss coating after the pattern application.

In addition, the tweeter should be mounted in it's final location, with all of those attendant loadings, for this evaluation, something I have pointed out about multi-way systems previously, but it bears having that caution repeated.

Again, thank you for your concern, especially about the placement of the, in this case, round dots of paint. Just as with the center domes of many drivers with voice coil dust caps, the initial pattern ring set needs to be at the point where the voice coil is attached to the dome, but wholly on the dome. Another ring may or may not benefit the dome, somewhat farther in towards the center and the final small 6 block set pattern and center spot at the tip are there to eliminate on axis beaming.

Bud

[dlr]

Originally posted by BudP
[B]Once again we are confronted with a lack of significant change found in what objective testing I have performed over the last 20 years or so. The treated tweeters, just as with the full range devices, exhibit a great deal more information in the audible signal, that is substantially below that of the first arrival / loudest impulse in amplitude, than the untreated drivers.

There is nothing to substantiate this. It is purely conjecture. You do not know the specifics of the change. You cannot know them without proper measurements.

I do also suspect that if we could graph these changes they would be very simillar to what John K found in his test and provided as a roll on roll off mouse controlled flick comparison.

You "suspect". Again, you cannot and do not know what is happening without proper measurements. More conjecture.

As for the mass increase, the dots themselves are so small and so thin that they will not provide appreciable mass change.

Reference comment above. Soft domes are often extremely light to begin with. Small dots may be a significant percentage of the mass.

The Gloss coating is another matter and beyond one light coating, will stiffen the silk cloth substantially.

That it will do and very possibly to detrimental effect. Reference comment above. What you are suggesting is essentially counter to what essentially ALL manufacturers apply to their soft domes, if they apply anything, and most do. That is, they apply a damping compound, sometimes remaining tacky. What you suggest stiffens and negates the damping, even that damping inherent in an untreated dome. And you do not know the specifics of the changes that you suggest other than conjecture at this point.

Much as you may believe otherwise, any additional mass, especially placed close to the former attachment point where it's mass effect is highest on a soft diaphragm, is going to lower the sensitivity. This is aside from any possible non-linearities that it may introduce. There is one and only one way to determine what is changing with any accuracy. That is by measurements. They are not difficult.

And again, to those who would consider modifying a good, soft dome tweeter, I suggest that you be prepared to replace it. This will not be reversible. And tweeters made today are likely very much different than those you may have tested in years past.

With good tweeters the most effective way to deal with any dome "issues" is a re-design or simply tweaking of the crossover. The changes are far more controllable and are at minimum, reversible.

It's one thing to suggest modifying full range drivers that are almost guaranteed to have issues. It's another to say that as some kind of "general rule" when you have no data on the driver in question and no evidence of the changes proposed, especially for any recent models. That is cavalier and not reliable.

Maybe you'd be willing to offer replacement costs if someone is ultimately dis-satisfied with your "qualified" suggestions that are not reversible.

Dave

[Cal Weldon]

Gentlemen,

Please try and keep your technical discussion here:

http://www.diyaudio.com/forums/showt...69#post1792669