I was looking at the published specs last night, and on paper at least, Zman has a really good point in their breakup seems to be much better managed which may allow the wide-range mid I was hoping for. Think I'll quit playing with the Fostex, although I was thinking of seeing what a no-network on a large baffle panel behaved like for experience. I'll play with the models and see if it worth building. The Mark looks like a much better choice.
I would be open to ideas on cone treatments. The only thing I ever played with was a very liquid RTV made for sealing windshields. Nothing to lose.
I would be open to ideas on cone treatments. The only thing I ever played with was a very liquid RTV made for sealing windshields. Nothing to lose.
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nope, I don't claim to heave heard any of the new drivers. My experience is only with the FE127 and the EL-70 (and the Fountek FR88EX) full rangers.
But the description by the OP with the 125 matches my experience of the 127.
Not everyone found the 127 a pain in the ear, but some did. It's possible that some people will find the 125 a pain in the ear, and others will not.
can't disagree with you on the Mark Audio drivers, particularly the EL70 & Alpair7 series
as to cone treatments - tread carefully, and there's more to it than simply adding mass or "sealing" fibers of paper cones, but my position on that is no secret - absence of scientific proof is not proof of absence of effect
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Cone treatment would be more focused on managing the breakup modes. Kind of a catch 22. If it adds mass, you lower the frequency of resonance even if it is damped a bit. most likely ( as well as VAS etc) if you try to add stiffness with very little mass, it should raise it, but may make it even more susceptible. I think just moving on is a better idea unless folks out there have some specific useful experience. If it was easy as slopping on some silicone, the OEM would have.
I was apparently not so cleverly alluding to the EnABL treatment - which is about far more than just adding mass, or managing breakup modes in the traditional sense ( slit or overlapping cone sections, a la Scanspeak, Lowther et al; cast/moulded ribs a la the very clever Fostex Sigma series; or any of numerous other methods of changing or interrupting the physical shape, construction or topology of the radiating surfaces themselves) According to the inventor, the polka dots do something else - just don't ask exactly what / how 🙄.
FWIW
LOCALIZATION
We are also able to perceive the direction of a sound source with some accuracy. Left and right location is determined by perception of the difference of arrival time or difference in phase of sounds at each ear. If there are more than two arrivals, as in a reverberant environment, we choose the direction of the first sound to arrive, even if later ones are louder. Localization is most accurate with high frequency sounds with sharp attacks.
Height information is provided by the shape of our ears. If a sound of fairly high frequency arrives from the front, a small amount of energy is reflected from the back edge of the ear lobe. This reflection is out of phase for one specific frequency, so a notch is produced in the spectrum. The elongated shape of the lobe causes the notch frequency to vary with the vertical angle of incidence, and we can interpret that effect as height. Height detection is not good for sounds originating to the side or back, or lacking high frequency content.
Source Hearing
I'll read all about. But like I mentioned earlier, if it was easy, (and worked) the OEM would be doing it.
I think it's safe to say that "reading all about it" - especially the technical discussions herein these fora will not answer the questions - including whether you can hear a subjective improvement .
As to "easy" - until such time as exactly how the process "works*" is understood, and automated production methods are devised to achieve the same results, it'll still be a manual process of auditing each driver model for the precise application pattern, then carefully painting all those morse code/polka dots.
* since first hearing a demonstration at Bud's home years ago, I'll make no apologies for believing it does - my experience then and since is all the "proof" required - other folks claim not to hear any improvement, and that's fine.
If "science" didn't have a history of discovering that we actually don't know everything there is to understand about ourselves and the universe, well , it wouldn't be science.
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Perhaps there are already so many compromises made in commercial speakers that it doesn't warrant the expense to add eNable.
Having done many drivers i would estimate that EnaBLing a driver at the factory, and not just the time and effort to do it, even if automated, but the time required between stages, would quadruple the cost of the driver.
dave
dave
Some of the claims of EnABL do seem a bit far fetched but the basic concept of adding damping material in a pattern near the perimeter of a cone is valid, and serves to provide both extra resistive termination of bending waves, as well as staggering what standing waves remain so that they don't all sum at the same frequencies at any given listening point.
I've been doing patterned damping of full range drivers since at least 2004 using simple adhesive foam strips and the improvements in cone breakup control can be really dramatic for some drivers, not so much with others.
In one pair of 8" coral drivers I managed to achieve a response from 3Khz to 6Khz (the main breakup area for that driver) which was flat +/- 1.5dB where the original response had a 3dB dip at 3.5Khz and a 5dB peak at 4Khz...(and that on a driver with a whizzer cone...)
The foam strips only flex in response to bending waves and therefore only target the breakup region, not affecting the piston range response including bass, where heavily damped surrounds would have a negative effect on bass performance.
Some info in some other threads including the pattern I used: (Although I believe the optimal pattern varies for each driver type)
http://www.diyaudio.com/forums/multi-way/192215-phase-plug.html#post2640803
Some other info on it:
http://www.diyaudio.com/forums/full-range/185012-whizzer-intelligibility.html#post2503393
One day I intend to write a proper article about it and fully document the technique including new more accurate before and after measurements by modifying some new drivers but it will have to wait for spare money (to buy some victim drivers 😀 ) and time 🙂
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Dave does have a point, TIME between steps. I can't believe the development and actual printing if automated would matter much when you build many thousands of them. I am sure a process could be worked out. I used to do things like that when I was in industry.
DB, please let us know when you "get around to it" I like the foam strip idea. Maybe a combination between the two ideas. Not much to lose as it peaks about 6 or 7 dB.
Exactly what foams you have tried would be interesting. Do they have any effect of surface waves so as to reduce diffraction at the edge? Off to read your links.
DB, please let us know when you "get around to it" I like the foam strip idea. Maybe a combination between the two ideas. Not much to lose as it peaks about 6 or 7 dB.
Exactly what foams you have tried would be interesting. Do they have any effect of surface waves so as to reduce diffraction at the edge? Off to read your links.
The foam strips are stuck to the back side of the cone not the front, so aren't visible, so they would not have an effect on diffraction near the front of the cone either.
As for type of foam its literally just self adhesive medium (?) density closed cell foam of the type that comes on big rolls to stick in door jambs as a draught excluder 🙂
It comes in different thicknesses and widths as well as colours. I've used both black and cream coloured. I've tried different sizes and at least for 8" drivers found 9 - 10mm wide by 3mm thick the most successful, which are standard sizes, typically I cut them into lengths of 20 - 25mm, varying the length a bit gives some control over the exact damping/response. (Too much damping can actually put a dip in the response)
I tried softer open cell foam but even in much thicker pieces it's ineffective.
The reason I need to redo my measurements from scratch with new drivers is that they were all modified back around 2003-2006 and I only had SpectraLAB at the time, which didn't do gated measurements so all my before/after measurements are contaminated with room reflections...nowadays I use ARTA which can do a FAR better job. (Also my mic and mic stand back then were poor)
This time I would do a more thorough job of measuring and documenting the results to help me better understand how it works. Although I think I have a pretty good understanding of it there are still some aspects that I'm not fully clear on. I do know that it works though.
I've posted quite a bit of info in threads other than those two links but in each case I've felt like I've threadjacked somebody else's semi-related thread, so when I do get the time for some more concrete measurements I'll start a new thread for it, as I'd like to further develop the idea.
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hey dbmandrake
what difference would i expect to hear if i put self adhesive foam strips between the driver and the cabinet? (12" cast frame audionirvana and 20mm plywood 5.6 cabinets)
thanks in advance
what difference would i expect to hear if i put self adhesive foam strips between the driver and the cabinet? (12" cast frame audionirvana and 20mm plywood 5.6 cabinets)
thanks in advance
If you have seen the Seas FA22, they have a cone with small dimples all over it. It would not surprise me if this is done for the exact same reason that people claim that ENABL works
The pair I have show this but it looks to me to be a by-product of the forming of the paper/pulp cone as opposed to an intentional pattern applied for a purpose.
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