[jrebman]

Just wondering what this is all about, what changes to the driver is involved, and any other thoughts on the subject.  I admit I know nothing about this, but am intrigued by it.

Thanks,

Jim

[TerryO]

Just wondering what this is all about, what changes to the driver is involved, and any other thoughts on the subject.  I admit I know nothing about this, but am intrigued by it.

Thanks,

Jim

Hi,
I'm not an expert on the Enable process, for that you'd need Dave (Planet 10) or Bud Purvine, but basically I believe that it consists of damping those precise points on the surface of your driver's cone that elicit a resonance or cone breakup somewhere in the frequency spectrum by placing a predetermined amount of damping material. A treated cone, will have small dots and dashes in patterns at specifically calculated intervals on the cone. There is an extensive thread on another forum about this, but unless there is a demand for it, I won't post it and be accused of being a Thread Pirate or Forum Jumper.

Best Regards,
TerryO

[aerius]

Google Patents to the rescue.  I could be wrong, but I think it works something like this: On a speaker driver, you have various materials which make up the cone, the surround, and the voice coil former.  The speed of sound through the materials differs a fair bit and there's sharp boundaries between the materials, so once you have a sound wave started it'll hit the boundaries and bounce back & forth multiple times before damping out.  This can smear the sound and wash out low-level details.  The EnABL pattern helps to break up those multiple bounces so that they don't corrupt the sound.

Whatever it does, it does work.  I tried it out on a set of crappy old computer speakers, they went from complete crap to a bit less crappy.  Still nothing close to hi-fi, but a bit more tolerable than before.

[jrebman]

Arius,

Thanks, that made things a bit clearer.  I have a pair of EnABL modified drivers on the way to me now, and I have an unmodified pair of the same drivers, so I'll be able to compare them -- both physically and sonically.

-- Jim

[shooter]

Jim,
I heard the comparison of the EnABLed and stock Lowther PM6A comparison at the RMAF, the EnABLed lowther sounded smoother and less distorted, even though the drivers are not identical, one is 8R and the other 16R, very interesting indeed, please post your impression when you get your drivers.
Shooter

[t-head]

I have a set of Bud Purvine EnABLed FR4.5C Hemp Acoustics speakers presently installed in a set of BLHs built by Ed Schilling of the Horn Shoppe in South Carolina. I have also applied the EnABL process to several  different speakers and am in the process of applying the process to two 6.5" woofers used in Eds' 'Cube' (sub). I would say first that the process is not about 'damping', although if not done properly that might be the result. It is about getting rid of resonances (and lowering their residence time) inherent in all speaker cones. This process, if applied judiciuosly results in an increased clarity of the music and reveals much more fine detail. Despite much testing, it appears the exact mechanism of this change is as yet unknown. This may well be due to a lack in testing parameters and transducer theory, rather than the treatment being suspect.

This clarity can be a two-edged sword, so to speak, as the quality of the recording, source and other equipment are laid bare. 'Be careful what you wish for' comes to mind. Since having the hemps treated, I have replaced much of my 'rig', as the faults of each piece were revealed. I do not regret having done this, but it should be considered by those contemplating EnABL.

What do I hear? Increased micro-detail in the music, increased 'presence' of the musicians, a wider soundstage and an increase in my 'immersion' into the music without 'listener fatigue'. I enjoy the result. YMMV.

Richard

[JoshK]

I've been corresponding with Bud for about a year or two now.  He made some output transformers for me that I haven't put to use yet.    He is currently working on some Karna power transformers for me and mentioned he was going to send me his CAD and Corel files (used for creating the EnABL pattern) for me to play around with. 

Bud is an extremely nice guy.  He doesn't know me from spit other than some email correspondences but he invited me to come over to his house when I was out in Washington last, but I didn't have the time. 

The whole EnABL thing sounded like voodoo to me at first, but then I started reading more carefully and I am impressed by the level of science involved.  I believe the science comes from studying turbulence of wings in aircraft, etc.  I can't say I really understand it, although I've 'tasted' some of the math when I was in college in a PDE course.  I think in practice they use water tanks and view the waves created.

It does something to break up the standing waves and disperse them I believe, therefore lowering the resonance.   Its a mechanical way of ridding stored energy.  I want to treat my Ciare drivers.  I will probably do one and not the other to A/B. 

[panomaniac]

I've EnABL'd 2 sets of the Hemp 8" full range drivers.  Not the prettiest job you'll ever see, but it does seem to work.

There is an immediate difference in the stereo illusion.  The image is fuller and deeper with the treated drivers.  After the paint cures for a few days, the distortion seems to drop.  It is especially noticeable on loud passages where the driver would break up and shout or honk before.  Most of that is gone with the treatment.

Planet 10 Dave talks about the reflections and the "Hall of Mirrors" effect.  The EnABL pattern seems to break up standing waves in (or maybe just above) the driver.  Bud Purvine, who invented the process talks about the reduction of stored energy, especially in the treated whizzer cone.

It's going to be interesting to see what the tests say, as they are developed.  So far, most tests show either no difference or actually worse results.  They sure don't sound that way.  I don't think I've talked to anyone who has NOT heard the difference  - and all called it an improvement.

My 2 cents.

[jrebman]

I heard one of the pairs Michael is talking about and have to say that I was very impressed.  They delivered excellent, clean response and no edginess of the kind I would normally expect to hear on the kinds of things we were listening to -- Hawaiian slack-key acoustic guitar -- the tone was exceptional and the highest strings, when plucked, sound very natural and real -- and not at all like they were rolled off, which seems like the only way I've been able to tolerate such sounds before -- rolling them off, positioning the speakers so that the hot spot is facing away from the listener, etc.

Now I can't wait to get my treated FE-127s playing here.

-- Jim

[planet10]

It is true that no-one has clearly shown what EnABL does objectively, it a couple posts get pretty close to waht i think is the most sensible "theory".

Talk to any decent speaker designer and he will tell you of the challenges of getting a surround that does its job, and yet minimizes reflections as the impedance changes from the cone to surround. Because this is next to impossible to accomplish* we end up getting a reflection at the surround which travels back down the cone and reflects off the the voice coil/dust cap, and so forth back & forth... what i call the "hall of mirrors" AZll this is happening 30-40-50 dB down so is VERY difficult to measure using eaily available measuring tech.

What EnABL does is disperse the surface wave that would reflect off the surround (or voice coil) before it has a chance to. This removes the time-smeared haze from the sound -- something we have all grown up with and have come to expect. This allows one to hear deeper into the music, and make audible all the subtle details that just make the music more real... and because there is less stuff to strain to hear thru the listener relaxes and can enjoy the music just that much more.

Any experienced listener hearing a set of EnABLed speakers can relate immediately to the above. You don't need to to be an experienced listener to hear the difference... i have yet to see ANYONE who hasn't reacted to what they are hearing. It is a joy to see that smile, the shifting and relaxing on the couch, the looks of wow that one sees of a person 1st exposed to an EnABLed speaker (and very reassuring that it tells you that you haven't been imagining it ie how can those little spots make such a difference).

It is next to impossible to try to describe what one hears -- you just have to experience it* -- but a Friday night spent at a friends playing with his new HD TV made me realize that there is a visual analogy (sorry Jim, this won't help you out)... a stock driver is like standard NTSC programming, an EnABLed speaker is like good HD of the same show. I still find it amazing that those little brown spots** can make such a difference.

*(to this end we have a set of Fonkens with stock drivers, and a set with our FE127eN, and are happy to do the demo for anyone who gets to our neck of the woods)

** (our standard colour for Fostex driver sis natural with brown spots and this phrase is actually a cuastomer quote0

The actual tech is simple. A regular pattern of bumps is placed so that the surface waves don't get a chance to relect... on a simple cone, a row near the surround, a double row near at the voice coil/dustcap edge, and a special pattern on the apex of the dustcap. Driver swith whizzers, phase plugs, or vertical impediments (ie a big trim ring on the far side of the surround) take more work, but it is just a matter of adding more rows. The spots/blocks are can be anything that causes a bump. Most often this is done with a specific acrylic flat paint (flat paint because it has more solids and creates a bump that is big enuff). The bumps don't have to be very big since the waveform they are disrupting is only a couple hundred molecules thick.

Depending on the cone material a "conformal" coating may be required on top.In particular paper cones. The primary purpose is to make a smooth surface for the waveform so that it slams into the blocks at an optimal speed. On [a[er cones this has a secondary benefit, in that it ties down the surface layers of paper fibres and reduces the self-noise of the cone. This is the same benefit that we have found from treating paper cones with things like puzzlekoat, dammar or BL100.

I ahve further found that on some cones a pre-coat is beneficial. My main experience here is with the Fostex drivers... this can be seen in my old modified drivers with my new FE126eN and FE127eN where i have married the tech from my previous tech with the EnABL tech to get something better than either alone.

In the interests of disclosure it should be known that Planet10-hifi is the 1st licensee of EnABL technology and we are shipping production FE126eN, FE127eN, & CSS  FR125SReN and are distributing a limited number of R & D drivers including Fostex & Visaton. We are also helping other small vendors to experience EnABL (ie a pair of Hawthorne Silver Iris on on theri way for me to treat & send back).

dave

[jrebman]

Dave,

Timely post.  I just spent a chunk of yesterday reading through the EnABL thread on diyaudio and have a much better feel for what this is about, sort-of how it works, and even what the patterns look like.

Yes, the fluid mechanics and vector algebra references were only vaguely familiar, and not easy to grasp without some sort of diagrams, but overall, I believe I have a handle on the basics.  The one thing that became quite clear very early on is that this is definitely something I will not be able to pull of on my own .  Maybe I could have devised some sort of mechanical aid for a much less intense version of the patterns, but once the details of the patterns were revealed, I just dropped all hope.  Never mind all the stuff in and around dust caps and whizzers .

I'm going to give Bud a call sometime soon.

Can you tell me what level of treatment the 127s I have are done to?

-- Jim

[BudP]

Hi All,

Just a note to let you all know about a three part EnABL tutorial, now completed, over on the Hawthorne Audio forum. Pages 8 and 9.

http://www.hawthorneaudio.com/forum/viewtopic.php?p=21618#21618

Most of the information can be found in the DIY Audio, EnABL monster, but I took pity on the newbies over there..... and on the rest of you too.

Bud

[jrebman]

Bud,

Welcome to the Audio Circle Single Driver circle.  Thanks for posting the link to the tutorial, and I hope a few others here will wade into these waters.

I'm putting my money where my mouth is and sent my highly prized, unobtanium Fostex F120As to Bud for EnABLing, and I have a pair of Planet10 modified FE-127s here that have also been EnABLed.  Those will shortly be going into a pair of Tekton Designs TQWT pipes.

Again, welcome, Bud -- glad to have you here.

-- Jim

[BudP]

Hi Jim,

Drivers are here, safely. Well packaged and sent by the only group of non ex government shippers, who do not regularly make footballs out of rectangular boxes.

I finished the Hemp FR8 drivers just this evening, so yours are up next. They look very interesting. I am intrigued by the coated aluminum center dome material. First time I have run across this. They will be treated in open air, as a vertical omni driver, so any peculiarities they may have will be evident and taken into account.

Do you want the pattern blocks to be visible, due to color contrasts, or invisible? I suspect you have no personal preference, but I thought it polite to ask.

Bud

[jrebman]

Bud,

I don't actually know what color the cone is now, or what kind of contrasting color you are talking about, but if it's easier for you to do with a contrasting color, then by all means do it that way.

I'll probably have another pair of smaller drivers to send you sometime after the holidays.

-- Jim

[RAW]

Having listened to the FR125S driver enough I am sure.
Dave sent over a pair modified and we have a few pairs here broken in in the similar cabinet size porting ect.
After 30 seconds of listening that is it.!!!
Stunned
All I can say.
Enough of a difference we have now put the EnAbl process on all the FR125S drivers we use in the Apex III and as of January the HT3.

[DaveC113]

Stunned
All I can say.

Even a short reason for being stunned would be nice... 

Dave

[planet10]

Can you tell me what level of treatment the 127s I have are done to?

Sorry to be so late answering that -- for some reason i am not getting notified of new posts.

Your FE127s are what i call FE127eN-b. They are the original Planet10-hifi drivers with EnABL added after. They differ from current versions in that the latest version has a bit less pre-coat (and with practise i've been getting more consistent with pattern application). It is hard to assign  a number to the differences in performance, but depending on the music being played with perform at 95-101% of the level of the current version. Since all of the -b drivers were sold at the original modded driver price they represent better value ($140/pr vrs $225 for the current version)

dave

[planet10]

Even a short reason for being stunned would be nice... 

Dave,

the short version "listen to a set of EnABLed drivers and you will understand"

the slightly longer (and no more illuminating) version, is that we have spent our entire lives trying to get used to the "hall-of-mirrors" time-smeared haze that every (unEnABLed) cone loudspeaker suffers from. When you 1st hear a speaker where the haze is no longer there ...

dave

[brj]

The whole EnABL thing sounded like voodoo to me at first, but then I started reading more carefully and I am impressed by the level of science involved.  I believe the science comes from studying turbulence of wings in aircraft, etc.  I can't say I really understand it, although I've 'tasted' some of the math when I was in college in a PDE course.  I think in practice they use water tanks and view the waves created.

Hmmm... I just found this thread, and that comment makes me curious enough that I'm going to have to go look it up.  Fluid turbulence along a surface is governed by viscous shear forces (those acting tangentially to the surface) and the surface properties.  A speaker driver interacts with air via a pistonic motion, thus the primary forces are normal to the surface (pressure) and tangential forces are comparatively minimal.

Decades of work has looking at passive boundary layer control mechanisms (trip dots, trip strips, vortex generators, "shark skin", riblets, plasma flow actuators, etc.) that would be of potentially similar scale to the EnABL pattern features, but the BL control mechanisms are all seeking to control shear interactions in the fluid.  In a laminar flow, you are trying to control various gradients to keep the flow from transitioning to turbulent, and in turbulent flow, you are trying to increase the momentum of the flow near the surface to keep the flow attached.  When it comes vehicle movement through a fluid, laminar flow is better than turbulent flow which is better than separated flow of either type, as each step represents an increased level of energy transferred to the fluid rather than spent on forward motion.  With the possible exception of shock impingement, you generally aren't worried about mechanical energy transfer to the surface from a shear layer until you are looking at very energetic flows - like the shear layer at the boundary of a rocket plume where you can experience noise levels in the 200 dB ballpark.  You have to withstand such large pressure forces induced by vehicle shape itself moving through the fluid that any acoustic noise (mechanical force) from a low-speed flow just doesn't rate as significant.  With a speaker driver, you have the exact opposite... you are trying to impart energy to the fluid, in the form of normal forces that cause wave propagation, but now care about relatively minimal energy lost in resonance... but that resonance is still the result of material flexibility in the face of normal forces rather than shear, as far as I know.

It does something to break up the standing waves and disperse them I believe, therefore lowering the resonance.   Its a mechanical way of ridding stored energy.

That makes sense, and I can see a possible connection in some of the underlying math... the math involved in solving how waves propagate through a fluid (air) are going to have some similarities to solving how waves propagate through a solid, especially since when you model such a fluid system, you artificially constrain it within a working control volume (which though not physically real, will reflect waves just as readily as the boundaries of a solid).  The differences are going to be the additional mechanisms by which the systems can lose or dissipate energy... vibration of a solid vs. ionization of a fluid, for example.