EnABL How-To for Fostex FE127e and other speakers

Welcome the EnABL How-To thread.

Specific attention will be given to the Fostex FE127e but the technique and principles are the same for virtually all multi way and single driver speakers.

EnABL is covered by a patent from Ed LaFontaine. The How-To thread will give information on how the specific tools for doing EnABL are available from Ed and completely treated speakers are available from Planet 10 Hi-Fi.

Everyone participating in or doing EnABL is encouraged to submit pictures and tips. This thread is for inquiry and will be built on the knowledge of everyone.


EnABL stands for Enhanced Acoustic Boundary Layer (in electronic transducers)

The pdf white paper on the subject is here:

http://www.goodsoundclub.com/pdf/EnABL White Paper.pdf

Much has been written about the theory over the last couple of years. The discussion located here:


.... has a wealth of shared information and experimentation on the principle.

The EnABL How-to is started to focus on what is needed and how to do it and less so on how it works.

Even in this introduction I don't want to get too long-winded and strain the concentration of the reader.

Enjoy what follows. You too may want to try the EnABL technique.
Ed LaFontaine said:

Uh, NO! I have patents on nothing. :eek:

You would be referring to our own BudP, to whom we owe that distinction. I just provide the kits so people can experience and decide for themselves. ;)

Ok. Well you see my difficulty. There is no rigor in my research and I'll likely drop the ball again. My goal is to narrow the focus as much as possible on getting the procedure done. This link you (Ed) gave me with a previous tutorial I pretty much found "on the fly."

That is included in the materials intro which follows.

Materials for EnABL application.

The application of the EnABL pattern is accomplished by using a caligraphy pen and nib with paint on the surface of a speaker cone and optionally on phase plugs. Other applications to enclosures and other surfaces have gotten experimentation but the materials in the How-To will focus on pen and paint.

There are many hobby stores with paint and pens beyond imagining for many crafts.

The specific products used for EnABL by those such as Dave at Planet 10 who does EnABLE on a production basis are specific and more difficult to locate. For simplicity's sake I'm going to
ask Ed LaFontaine who supplies the kit of materials needed to the DIY readers for a description of the specific products in the kit. The EnABL kit is reasonably priced and you can use PayPal
or the usual means to obtain it from Ed at:

[email protected]

Ed has graciously supplied the list of components of the full EnABL kit:

This kit will include the following:

1) type B nib holder
1) set, A-1 through A-5 Speedball pen nibs (5 nibs)
1) #56 Speedball pen nib
1 oz. Microscale MI-4 Gloss coat
1/2 oz. Floquil Poly Scale #404106 flat finish (stealth finish)


That's the kit.

In the course of the discussion of treatment for the Fostex FE127e, Damar Varnish (sold in hobby stores) and Modpodge or Puzzlecoat will also be referenced.

I am not experienced with doing EnABL at this point at all. Therefore I will depend on the forum regulars who have done the procedure for advice.

The thread should follow a scheme of Material purchase and description, Preparation, work area Setup and finally Application followed by cleanup. I'm bot assuming any craft experience of the reader or myself either.

A bit more on materials is here in an apparent separate tutorial. See postings #14 and #15


I hope to get all this material gathered together so that a work flow can be repeated by the reader without any gotcha's half way through.

The specific material addition noted is the Rapidograph drawing instrument for making the smaller dots. Quoting:

"A useful addition to the arsenal are Rapidiograph technical pens. They make placing tiny dots on domes and whizzers much easier, for some and more difficult for others, like Dave from Planet 10, who uses them only under duress. Sizes from .02 through .085 are useful, but spendy."

-- from BudP

That's all I have for the introduction on Materials today.

Aids for use with the materials such as template guides gauged for specific speakers have been discussed as well. The guides provide a way of applying the paint without too much wander on the speaker cone. But this too is something I'm trying to pull together for my own use.
I think the idea is a good one. There are a large number of treatment pages for specific drivers, but they are buried in a wealth of other information and can be quite difficult to find.

I have attached a text file with all of the currently known threads for EnABL and a list for all of the driver specific pages. Each page has an attached pattern application set. These are in PDF format, but originate with the Corel Draw vector program and these can be made available.

There is also a picture exhibit for each treated driver that can be an important resource in determining whether you want to put the effort into a particular driver or not. The url for this exhibit is also noted in the attached text file

I will say that I have never found an unworthy driver. Even the most awful PM 2 inch, alleged, full range driver, with corrugated paper surround and an X-Max of .001mm, can be made to sound startlingly good.

So, proceed, please. I will lurk around to help where needed.



  • enabl posts for treatment text file.txt
    4.6 KB · Views: 731
And for Dave this is a pre EnABL question related to the previous answer above and the posting reference.

I have been staring at my FE127 for days trying to figure out how to get a proportional trifoil pattern to come out the first time. Your shop pictures show a very uniform application. And with what applicator? A brush or a foam pad?

Elsewhere there was some mention of template and application.

Can you describe this?
FE126/127 pretreatment

I was just thinking that this would be a good place to consolidate pretreatment techniques.

Why pre-treat? The FE127 (and FE126) have a nasty resonance at about 7k which can cause listener fatigue. The Trifoil pattern + the puzzlecoak (aka modpodge, etc) works to exacerbate this -- as well as the puzzlecoat's common roll of reducing cone self noise.

We have Mark McKenzie to thank for leaving a few breadcrumbs to point out where the pattern should be. My application is not necessarily the best or most effective, but it goes a long ways (going further would require some serious lab work and the sacrifice of more FE127 than i can afford).

Here are the measurements that Mark did.


and Mark's breadcrumbs "The critical regions where the mechanical modifications are made are 9 and 17 mm in from the outside edge of the cone".

This info and a bit of experimenting led to the current trifoil pattern.

On the 1st drivers i used a compass template, a pencil and a ruler to create a guide for pattern placement.

My 1st template consisted of 2 appropriate size disks used in conjunction with the centre cylinder from an empty solder spool (which conveiniently fit over the dustcap to centre it, now i have a 2nd generation template made from a dead FE127 cone.

The trifoil pattern is painted on using damar. First i place the template and using a very small pointy brush create 3 points to define each of the 6 arcs. Then using an appropriately wide brush, i stroke over these to form the 6 arcs, then join the ends. When painting the arcs i use my the opposite side of the driver as a pivot point for my hand and sweep the arcs on.

The damar will run fairly easily, so one has to be careful with the original spots (and then getting under the template & wicking) and with the brush load of the damar when doing the arcs.

The cone where the trifoli pattern is should be semi-translucent and visible from the back where the damar soaked thru.

After the damar has had 24 hrs to dry, thinned modpodge is used to completely coat the cone & dustcap. After at least 6 hours to dry a 2nd coat can be applied. You want to use as little as possible to adequately cover the cone. The 1st coat seals and ties the paper fibres on the surface togther, the 2nd sits on top of the 1st.

How thin is thin? It is hard to give a formula as the consistency of each bottle starts out different and changes as it gets exposed to the air and as it ages after exposure. It is still a matter of feel to me. It should be runny enuff to smoothly coat the cone, but not so much that it soaks in. Someone felt it and said about the consistency of transmission fluid.

You want to add each layer as quickly as possible, as at the right level of thinning it starts setting up quite quickly (this can be a real issue with big cones, as the start can start setting up before you finish getting all the way round). A emptied brush that has been dampened in water & tamped can be used to finish smoothing things out in this case.

With the FE126/127, a quick application to get the cone covered (as uniformly as possible) and then a couple rounds on the lazy susan with radial strokes from the dustcap out to the edge to smooth things out.

1/ a wet/damp q-tip(s) are useful for cleaning up any puzzlecoat that gets on the surrounds, a damp paper towel for stuff that gets on the bezel.

2/ that black gooey glue used to hold the dustcap seems to be a great source of small bits that get dragged out onto the cone, Dust & hairs can also get into the mix or onto the cone, A damp q-tip helps pick up the ones that can't get swept over the edge.

A good brushing with a clean brush, and maybe even a squirt of air can really help minimize the problem.

3/ while the dustcap is damp from the puzzlecoat it is really fragile and can easily be dimpled/creased. Same applies to the cone to a lessor extent.

Pictures to follow (i'm not at my main puter at the moment)

Mark McKenzie thread:
My original FRForum thread with really early info:
A couple more diyA threads with tidbits:

Here is a FR measure done by Mark Fenlon in the anechoic chamber he uses to test his Mark Audio drivers. Althou not directly comparable to Mark's measures above (different kit & room) it does tend to indicate that the FR peaks have been considerably flattened.


The resonances are not completely gone, a ghost of them can still be heard when compared to a very smooth driver like the FX120

use of a foam pad

The post just above is a very good description of the Mod Podge part of the process.

What follows is my hands on experiments in doing it.

Treatment process For the FE127 the speaker begins with applying the
Trifoil pattern. I have not got to that yet and am awaiting the delivery of my Enabl kit.

The second procedure is the conforming coat of Mod Podge on which the actual
Enabl pattern is applied.

This is about experiments with application of Mod Podge prior to any actual work on the target
FE127 speaker itself.

Updating this how-to diary, I did some experimentation on a couple of my sacrificial experiment speakers. This does not mean they will be unusable-- just less pretty.

The conforming coat that turned out best for me was a dilute mixture of the Mod Podge.

The Mod Podge I used is the matte version. Gloss version is also available and may be
preferred. Current info on this is that matte or gloss will perform the same with an edge to the gloss.

Foam pads for application which are well-drained (free of drips) work well and minimize
brush strokes.

From other sources, Dave Planet 10 said that the dilute solution will soak the
fibers during the first coat. This is problematic to be sure and I don't
know how else brush strokes can be avoided. There is no apparent bleed through on the
test speakers on the rear of the cone. Also no saturated wrinkle spots.

A second coat (which is recommended) gave the same brush free surface.

However after several tries of applying a third coat on different speakers, brush strokes were unavoidable for me.

I would stop at two coats for this reason.

Recommended dry time is 6 hours or more between applications.

The conformal Gloss coating material you will receive in your kit acts as a distribution membrane and forces areas not covered by pattern blocks to conform to the energy emission of areas directly controlled by the patterns.

When we began applying the new mid cone, more or less, block patterns, the use of Gloss coat became less important for that distribution membrane portion and became more important for micro information expression. Less Gloss coat is now needed than before and should be approached carefully, with about 48 hours of dry time between coatings and at least an hour of listening before another coat is applied. The choice of how much to apply of this Gloss material will now be a matter of taste. How much artist emphasis information do you want, how far down into the decay structures do you want to hear and how much musical color do you want to listen to will be your major categories of decision.

You can get offensive amounts of all three categories with too much Gloss coat applied. Previous to the mid cone rings (thank you again soongsc) too much Gloss made all of the above more apparent, with each coating, but also added a sharper and sharper edge to leading edges of transients and eventually made all sounds hollow and brittle.

Recently a maximum of three coats of 50% cut with water Gloss was needed to control an all aluminum driver. Before the mid cone patterns revolution you could not have applied a thick enough coating of Gloss to an aluminum driver to kill the resonances. I am speaking of the Dayton 175-8 drivers here, not the Jordan JX92s, which needs no Gloss at all, due to the care in choice of materials used for it's construction.

Now we usually use less than three coats for paper cone drivers and one 25% Gloss to 75% water mix for a fully patterned silk dome tweeter.

My diary on this continues.

Good news is I got the kit in the mail. The bad news is the postman stuffed it into my apartment mail box.

Everything should be ok. I didn't open it yet though.

Since I will be using some test objects to apply the pattern, I'm redoing a couple of small boxes to give a local A/B test.

The speaks I have are unfortunately between sizes for my hole cutters
and so I have to modify my router jig.
My goodies seem to be intact. Packaging of the FloQuil and microgloss is very good.

[I still do not get why the Testor's model railroad paint is so difficult to come by locally. Maybe I will consult the local model rail rooad groups or look for the brand as "Testor's Poly Scale model railroad paint" as marked.]

The Polyscale shipped is flat white which is good for my test pieces which have black cones. It may be more problematic for my FE127e with the much lighter cones.

Thanks Ed.

The serious questions about Setup and preparation should follow.

I made a stab at using the grid maker which Ed suggested. I can't say it was very successful. The radians (?) did not line up as they should.


All this means is that if there are visual aids and templates and the process is known and not proprietary, I have not been able to tease these effectively out of the long discussions.