GoodSoundClub - Romy the Cat's Audio Site - The corkscrew boundary effects?

04-14-2007

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Bud
upper left crust united snakes
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EnABL: Just a note to awaken all of you peaceful sleepers

Hi all.

I am just supplying a couple of threads that are dealing with application and the theory behind the EnABL process I provide information on here last year. Romy, you should not go there, it will make you crazy and you will have to insult someone. For those who are interested here are the thread.

http://www.diyaudio.com/forums/showthread.php?s=&threadid=100399

In a short while I will start a third thread at this DIY Audio site showing how to actually treat a set of speakers. Lowther s and Fostex drivers, with pictures and text.

Bud

04-14-2008

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Romy the Cat

Boston, MA
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The Budificatiuon of Macondo.

I am playing nowadays with Bud’s EnABLing ideas.

http://www.romythecat.com/PDF/EnABL%20White%20Paper.pdf

Look also for the posts in the linked threads.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

04-15-2008

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Romy the Cat

Boston, MA
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Budificatiuon of Macondo, the latest version.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

04-16-2008

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Romy the Cat

Boston, MA
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The corkscrew boundary effects?

Well, what I am trying to do it to smear or to defuse the virtual edge of the horn. It is not exactly the same what Bud does with him application of patterns on the cone driver but it very much similar. Toward to this end any random pattern that would break up the pressure wave reaching the horn leaving moment at the same time would do. My idea in fact go father and I am experimenting now with spiral positioning of the dots, where one side of horn has dots doing in depth for 2” and another juts for ¼”. That might introduce an effects of HF leave the horn’s boundary not at the same time but gradually… So fur the results are more at the level of intellectual satisfaction and the sonic impact is not as huge as it reported with application of EnABL on the full-range drivers.

Rgs, Romy the Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

04-17-2008

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Romy the Cat

Boston, MA
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In the test mode.

guy sergeant wrote:
What are the pads you are applying, ie what material?

I do not think, and I might be wrong, that material matters. Bud, doing his cone driver feels that deviation of mass maters and he “smears” the bouncing of the transition line. In my case I feel that it might be the micro-deviation of height is more important and all that I need to do is to introduce more “hairy” surface at the very edge of the horn.

I use photographic masking tape. Initially I used 2 layers and now I am at 2 layers. The masking tape is good because it leaves no marks after I remove it… I am sure anything else might be used. Bud uses paint’s drops. I might do paint as well eventually after I experiment with removable patterns and found that the whole idea worth to be employed.

Rgs, The caT

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

04-17-2008

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cv
Derby, United Kingdom
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Enabl test mode

Hello Romy,
While you are in test mode, have you played with bath towels around the horn mouth? There's a long thread here by Jack Bouska; you may or may not agree with the content, but interesting how towels make hifi news sound better (if not more trustworthy)

http://www.audioheritage.org/vbulletin/archive/index.php/t-12967.html

I think the edge termination is less of an issue if the horn is operated above cutoff, but in the case of your midbass horns, with the floor coupling, things should be more interesting.

cheers
cv

04-17-2008

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be
Copenhagen, Denmark
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Termination

"I think the edge termination is less of an issue if the horn is operated above cutoff, but in the case of your midbass horns, with the floor coupling, things should be more interesting."

There would be no effect at all, of the arangement in the picture, at low frequencies around cut off,

The magnitude of the effect of objects on sound waves, depends strongly on to what extent the wave can couple to the objekt or if it can "see" the object. In this case of soundwaves in the half open you must look at how large the object is compared to the wavelenght.
As depicted here, my guess is that the effect would become stronger around 10kHz, that if there are any soundwaves at that frequency in the area where the tape is placed.
That does not mean that there will be no audible effect of the tweaking though, just less than posible, but maybe exactly what is asked for.

Hi
be

04-17-2008

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Romy the Cat

Boston, MA
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The jury is still out…

Well, it hard to tell if any effect is in place. I have a conceptual felling that the effect shell be auditable and I would like to say that it is but I am not convinced that I hear any substantial difference at this point. Bud believes that in order to observe the effect I need to pattern both right and left channels. I did experiment only with left channel so far and perhaps I need to do the right channel. There is perhaps a very-very minor change with ability of the horn to care HF amplitude before it become “too bright”. However, the degree of this effect is very minor and the “comparing” too spread in time in order do not blame electricity or anything else. It looks like the pimples in the edge of the horn have no damage to sound. Would they provide the improvement is still deliberating… The Cat

PS: BTW, I think the best accidental pattern would be to use two lines (in chess order) of randomly span Stars or even better Stars of David. Would it be too presumptuous?

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

04-17-2008

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be
Copenhagen, Denmark
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Terminations

The Enable patterns are efficient on a loudspeaker membrane because there is a strong structural coupling of the transversal sound waves in the membrane it self and the additional mass and damping of the spots.
In this case the situation is different, you will need something comperable in size to the wavelenght of the frequency range in question.
David stars? Haha, very funny, and it would work fine. Triangels with one corner pointing towards the center of horn would maybe be better, check out the "Manger Wandler" http://www.manger-msw.com

04-21-2008

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Romy the Cat

Boston, MA
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OK, I have to admit: “something” is working here.

I am not quite sure what it is and how I do detect that something is going on here. I “spotted” the left channel

And over the course of the week I do detect some HF fog “drag” in the right channel. The left channel is clean like dew but right channel has some kind of mist of HF. The right and left channels out of course the same….

Well, I did not put Budanized the right channels yet but I got rig of the “mist” wrapping the towels around the MF horn. The identical result I get running the right MF and tweeter at minus 1dB…

The next step will be to put the pattern on the right MF horn.

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

06-13-2008

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Romy the Cat

Boston, MA
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Horns edge biting: OK, it is working.

Approximately a month ago I patterned the horn on the other channels and I have to admit the “tweak” is working. It feels as it acts as a sonic defogger minimizing some stray HF dispersions from MF channel. Generally the effect is positive but not huge. What however is very strange is that the effect of practically not observable with the only right or only left channel are ruining – I need to run full stereo to clearly recognize the contribution of the horn’s Budanization. When I run both channels in full mono it also works but as soon I shut down right or left channels the effect become not observable and the Budanization has virtually no positive or negative contribution. I have no expiation to it.

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

06-09-2011

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Romy the Cat

Boston, MA
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Budificatiuon by Russians

Romy the Cat wrote:

Here is the very same idea that I had with introduction of bitten edge of my MF horn only made but some Russian guy. I do not know him and I do not know what drove him but the intention is very clear. He uses 4-5 non-compression drivers with looks like 140Hz horn and he put on the perimeter of the horn a line of animal fur.

http://photo.qip.ru/users/yras/3640941/?mode=xlarge

For sure it does not look sexy but it is an elegant idea. What I would like to see is the horn is made to accommodate the fur like. I mean the horn might have a small 4-5mm trench into wish the fur might be inhaled. It would look very accurate and shall be very effective.

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

06-12-2011

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rickmcinnis
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I think "the Russian" is simply trying to control diffraction

I have used thick wool felt around the perimeter of my round horns at times. Having owned a pair of ROGERS LS3/5a's in my youth and being amazed at the huge sound those little speakers could effect one tries to re-use ideas. Diffraction control is a worthwhile pursuit. I, too, was disappointed with how Dr. Edgar flattened the front of my horns which led to my suspicion that some kind of diffraction control was needed.

For some reason many years ago I removed the felt. Makes me think I should give it another try.

The EnABLE idea is fascinating but I have never tried it. I do not remember the tape remaining on any of your horns. One thing to stick the dots and dashes on a five inches speaker cone. The thought of placing those all around the horn made me weary. Are you still experimenting with this?

I think you might find some value in Mr. Purvine's ground things. One wonders if, at the high state of development of MACONDO, there is anything to gain but like all tweaks what is gained is usually unattainable any other way. In my experience they added gracefulness to my TAD 4001's (along with lining the back chambers with wool felt).

Could very well be that the VITAVOX does not need whatever it is these things do.

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	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	It is possible to eliminate some forms of gross side ba..	Re: EnABL Pattern and Ribbed Cones...	Audio Discussions Forum	22	168225	07-08-2005
»	New	Tweeter for Vitavox S2. High-sensitively ribbons?..	Correction: Townshend Ribbon and sensitivity....	Horn-Loaded Speakers Forum	64	847234	10-19-2006
»	New	Lowther Driver..	Selling OCD Lowther DX-4s on OBs, +++...	Audio Discussions Forum	62	605001	11-15-2006