Thank you for those links Bud, fascinating and beautiful, but other then by adding two and two and getting a very unlikely number I can't see the relevance. Are you saying that applying this pattern to a baffle somehow tames resonance and makes it usefull? I think it's just as likely a piece of chewing gum stuck in the corner will be effective, and while we are on the subject how was this eNabling pattern arrived at? Was it exhaustive trial and error? a wild but fortunate guess? The physical embodiment of a hypothesis? I'd love to know.
Exactly, I think there may be a misunderstanding of the way a wave propagates and wind blows ( Which is sad).
Hmm, I must not be thinking straight today. I should dig out my physics text books. I need a refresher I think.
You are correct. Starting from rest, one cycle is composed of one motion forward followed by one motion backward before returning to rest.
If you reread my post #72 and then the follow ups, this whole discussion about flow, Reynold's number, and vibration is a perfect example of what I was describing. The amount of bad information and technically impossible or incorrect posts is rising on these forums. The people who know better have left.
Enable does slightly change the sound of a driver, maybe better maybe not it is a personal preference. I have not been impressed the few times I have heard treated drivers. I think my hearing likes a crisper/brighter top end, probably age related, and Enable tends to mellow the high frequencies. However the claims of how Enable works and the impacts it has on the room and the enclosure baffle do not make sense, they are not possible based on Physics.
Martin
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You know B&W had this "golf ball" front baffle on some of their speakers... said to reduce baffle diffraction by breaking up waves traveling across the baffle. But the depth of the dimples was significant compared to the dots being proposed here. Plus the pattern of the dimples was all over the front baffle, not in any particular format. Such a thing might have some real effect.
Only true if the cone is a true piston, no? If it's flexible at all, there MUST be some air movement over the surface as the surface flexes...I would think. (OK, not much, but still...).
There are oscillations, air moving back and forth very small distances. There is no net flow, air does not move over the surface and not come back.
So here is a brain-teaser on this subject....If a cone tweeter is cycling at 20K hz, each sinwave cycle is appx 17.22 mm long, and the cone displaces one mm forward, following that precise sin curve, compressing a small mass of air molecules. When it reaches the limit of its excursion (Top of the curve) Why does it accelerate to a higher velocity once this mass leaves the cone???
At much lower frequencies, why does this mass accelerate some 100X its initial mass acceleration????
_______________________________________________________Rick..........
At much lower frequencies, why does this mass accelerate some 100X its initial mass acceleration????
_______________________________________________________Rick..........
Imagine it is 1972, in LA and you walk into Henry Radio at Walt Jr's phoned insistence and he shows you a pair of Ohm F Demo's he has conned Marty into sending him. He lifts the cover off of one unit and your eyes fasten on the odd looking slits in the paper, at the bottom of the long inverted cone and you think to your self "well, that's wrong". You foolishly mention this to Walt and he says "can you do any better?"
And so you purchase a pair for $600 and proceed to apply these pattern blocks that arose in your minds eye, immediately after you had the thought about how wrong what they had done was (this being a normal event for a graduate of the Art Institute of Chicago). A month later you have a pair of Ohm F's that emit a spherical wave front, rather than a frequency stepped, cylindrical one and you could tell this only because the sound does not change no matter your position around the speaker. You fiddle about with other direct radiator drivers and find some fairly dramatic improvements in quality (remember, this is still the 70's and most speakers were not very well designed in comparison to what is available today). You look for test equipment that might show you something and find nothing you can possibly access or afford.
5 years later your 7 year old son rips the input plug from the heavily uprated SAE, Germanium transistor Mark 3A amplifier. The wire wound resistor network protecting the transistors evaporates, as do the transistors and the filter capacitor emits heavy smoke. The Ohm F crumples and you and your son are deaf for a few hours, while he cries in a wild and crazed fashion. Eventually mom calms him and asks what that was all about. Son says" I wanted to let the music people out!!!!" and begins crying again. Eventually you learn he thinks he has killed them all by imploding them in an "inplosion".
Upon reflection over this period of time, you realize that your own childhood had a number of instructive pursuits that likely as not provided fodder for this madness. And, you go on a hunt for the obvious explanation for why the spots of paint have made a big enough difference that someone so young and innocent of malice could have become convinced there were live people inside of the speaker cone. Surely there must be an explanation available....
The only mention of anything that even remotely seems to bear upon this effect, upon a non pistonic driver (do read Lincoln Walsh's papers), might be a single chapter from Baranek's "Acoustics", where he admits that the piston models that the rest of the book is devoted to, don't really explain what he shows in graphic format within that chapter. And so you begin to think about the problem....
There, you have it.
The utube movies show this lateral movement quite clearly, it is a rotating torus and the air flow does come back.
And than there is this very unusual comparison between treated and untreated drivers. The untreated driver sure looks to me like it is reprinting a characteristic response to the pulse, a few times within the 4ms window. The treated driver sure looks to me like it is loosing energy, in a parabolic fashion, with very low amplitude reprints.
Enable Tests
Just to stir up more acrimonious arm waving, we have a version 2.0 for baffles. And worst of all, it is a way to place a pattern ring set properly, in the middle sections of a baffle, as opposed to the edges. Take your trusty pen holder and tap radially away from a hole in a baffle with the small diameter tip. preferably one filled with a driver. When you find a subtle change in the sound of the tap, almost as if some directional effect was occurring to the decay portion, place a set of blocks right there, in a circle around the hole. You can confirm the need is circular if you must. Paint or plastic shelf paper or mortite worms are fine for this.
Once the pattern blocks are applied, the directional change disappears, until you get to the next one. So far, the ring set centers of circumference appear to be multiples of the radius of the hole or driver filling the hole. This is NOT an exact prediction, just close enough. This can be done in addition to the patterns around the edges.
Could you be a tiny bit less oblique please Scott?
" The utube movie shows this lateral movement quite clearly"
This is the most prepostrous analogy!!........This is an interaction of a vibrational surface upon a SOLID, not air. Solids by and large are in-compressable, unlike air, which is compressable. Trying to stretch the analogy to air is just plain un-scientific. Undeserving of believability.
____________________________________________________Rick.............
This is the most prepostrous analogy!!........This is an interaction of a vibrational surface upon a SOLID, not air. Solids by and large are in-compressable, unlike air, which is compressable. Trying to stretch the analogy to air is just plain un-scientific. Undeserving of believability.
____________________________________________________Rick.............
Arcane waffle peppered with spurious scientific references does not strengthen your case and your conclusions that confuse vibration with airflow are an indicator of your misunderstanding of science, specifically cause and effect.
Interesting discussions by all, but I wonder if it should be moved to the listening impressions and techniques thread, as most of it is a bit far afield of baffle enable.
Bud, I love the story of the (your?) child with the music people. I used to sit in front of my little record player wondering how the people got into that box to make music...Now, wasn't there a story about a fish tank too?
Carl
Bud, I love the story of the (your?) child with the music people. I used to sit in front of my little record player wondering how the people got into that box to make music...Now, wasn't there a story about a fish tank too?
Carl
Or, like my kids who also wonder where the singer is, he just heard a speaker and wondered. Much like most technology. Like how my kid thinks there are people in the tv. Even though it's not 3d and I've explained it to him. He even thinks a cartoon is real 😱 Chances are your kid, was just a kid like any other, and didn't find enable any more life-like than my $20 peerless woofers 😉
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