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#1 2006-04-01 03:23:14

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Modded FE126e FE127e

westend wrote:

Also, a little bird told me that there are some FE127 mods being done and they will be discussed in the near future.  Man, that last bit sounds almost cyptic, upon a reread. Stay tuned, I guess, good things are coming with these drivers.

Time to start the discussion.... i have no pics of the FE127s i did 1st, but here are the FE126 that got installed in the A126 earlier this evening.

modded-FE126-s.jpg

dave

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#2 2006-04-01 03:43:17

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

The mods comprise 2 parts -- what i'd normally do to a driver based on tweaking them for 25+ years with the addition of a twist based on clues from a post by Mark MacKenzie on diyAudio.com. The entire post: http://www.diyaudio.com/forums/showthre … post547855

MarkMcK wrote:

A few points of explanation: Fostex’ banana paper cones are very noisy with vibration modes. They are much worse than polypropylene or the mag/AL alloy...
Cone vibration modes may be independent, loosely coupled, or tightly coupled. Fortunately, several vibration modes in the FE126E cone are tightly coupled. That means that controlling one mode may take care of more than one. For the modification documented here, two regions of the cone are mechanically modified.. The critical regions where the mechanical modifications are made are 9 and 17 mm in from the outside edge of the cone.

Puzzlecoat by the nature of how it works deals with the "noisy cones". The 9 & 17 mm mods are inspired by mark's post. I have no idea if what i've done is anywhere near what Mark did, or whether they are as effective. I used the tools at hand and that i'm familiar with. The results were positive (Chris' comment -- by phone -- after he got a chance to listen to the Fonkens with modded FE127 went something like this "HOLY SH#*"). The comment that i made to westend was "turn the Fonkens from good to stunning".

With just a quick listen, the FE126 in the A126 exhibits similar improvements to the FE127 in the Fonken. "Graininess" from the noisy cone are gone. FR is flatter. Bass is better .

before-after-fonken-FR.gif

I've only done 2 drivers so far. The technique will improve. The detail will likely change. I want to try some other colors (the black does 2 things -- it will make the FE127s hide better behind their grills on the diyAudio Ref ML-TLs that Chris' mom has, and it hides the pencil marks.

One thing i'd like to know is -- how many would i have to buy to get them without the dustcaps installed?

dave

Last edited by planet10 (2006-04-01 03:44:38)

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#3 2006-04-01 03:58:28

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

In the interests of the community participating in optimizing the process this is what i did:

0/ ductseal to damp the basket and smooth the shape of the back. A "puck" of woolfelt to further quiet stuff off the back

The cone

1/ i marked the rim just outside the surround into sixths

2/ using a clear plastic ruler i drew dots on the cone to mark off alternating arcs -- 3 at 9 mm, 3 at 17 mm

3/ using a Q-tip i applied damar to the arcs as in the bottom images above. (be careful, it is really easy to get too much on the tip and have the damar run -- i dabbed the tip on a piece of cardboard to suck up that 1st bit). Let dry.

4/ Then i applied 3 coats of thinned puzzlecoat to the cone (in this case thinned with vintage Peerless black ink)

Comments:

1/ are sixths the right number -- is that scheme too symmetrical?

3/ How much damar? The 127s got a bit more, and the ends of the arcs were connected (because it ran), With the 126 i was more careful. With nothing but gut to back it up, somewhere in between....

4/ does the black ink play any roll. Should the puzzlecoat be thinner (ie a lighter coat -- again my gut says not more).

Would alternate dopants work better?

Let everyone know how things turn out if you try this, and any alterations... maybe Mark will even chime in (he is certainly the expert on the subject of controlling cone resonances)

I take no responsibility if you go overboard or don't like the result. So far you only have Chris' and my opinion to go on.

dave

Last edited by planet10 (2006-04-01 04:06:31)

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#4 2006-04-01 09:34:49

Geek
Member
From: Rosedale, BC, Canada
Registered: 2005-11-09
Website

Re: Modded FE126e FE127e

Hi Dave,

Have you considered the effect of perhaps tacking on a little whizzer to better the HF response?

Cheers!


-= Gregg "t3h GeeK" =-
http://geek.scorpiorising.ca
"Ratings are for transistors, tubes have guidelines"

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#5 2006-04-01 09:39:50

westend
Member
Registered: 2005-12-31

Re: Modded FE126e FE127e

Dave, thanks for sharing the modifications. I was interested to see the rise in response on both the higher and lower end of the response graph. Is this the result of removing the close-coupled vibrations?

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#6 2006-04-01 11:06:44

LowVoltage
Member
Registered: 2006-03-27

Re: Modded FE126e FE127e

Dave:

How much did you reduce the puzzlecoat? ...... 50:50 75:25

Mike

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#7 2006-04-01 14:19:59

fergs1
Member
Registered: 2005-07-27

Re: Modded FE126e FE127e

greeetings gentlemen, for the benefit of us colonials(Australia), what is puzzlecoat and can i eat it?             cheers fergs

Last edited by fergs1 (2006-04-01 14:21:04)

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#8 2006-04-01 16:02:42

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

Geek wrote:

Have you considered the effect of perhaps tacking on a little whizzer to better the HF response?

No. And i don't think really needed. I do miss not being able to phase plug these. We had a set (mostly) working and it helped the HF quite a bit.

dave

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#9 2006-04-01 16:05:43

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

westend wrote:

Dave, thanks for sharing the modifications. I was interested to see the rise in response on both the higher and lower end of the response graph. Is this the result of removing the close-coupled vibrations?

The low & hi-end are possibly a rise, or they could just be a flattening of the mid-range hump. My measure system is still somewhat crude and relative levels shouldn;t be read in. Reduction of leak-thru the cone could give more bass SPL. And the additional mass of the PK would subtly change the bass alignment.

dave

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#10 2006-04-01 16:08:58

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

LowVoltage wrote:

Dave:
How much did you reduce the puzzlecoat? ...... 50:50 75:25

That was a seat of the pants at this point. And depending on how thick the puzzlecoat you have is would be different. I thinned it until it was "runny"

If you want to be real careful you thin quite a bit and add more coats if needed (i'm actually going to do that next, to see if more penetration below the surface pf the paper helps things out

dave

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#11 2006-04-01 16:11:26

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

fergs1 wrote:

greeetings gentlemen, for the benefit of us colonials(Australia), what is puzzlecoat and can i eat it?             cheers fergs

You can eat it, but you might get sick. Puzzlecoat is a generic name for a PVA compound used to coat puzzles. The stuff i actually used is ModPodge. In a pinch you can use white wood glue (the end finish & pliability of actual puzzle products tends to be a bit better).

http://www.t-linespeakers.org/design/tweeks.html

dave

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#12 2006-04-01 19:24:23

JohninCR
Member
Registered: 2005-08-10

Re: Modded FE126e FE127e

FWIW, I've used food coloring to thin PVA glue.  A lot of blue with red to make a very deep purple works very well on greyish black cones to make them a true black. 

Since I can't find dammar down here, I'll go with unthinned PVA dots like I've seen Mark use before for the rings on my 127's.  Then probably straight blue food coloring as a thinner for something colorful and worst case the yellowish cone color will result in a green tint to the blue.  I'll post some pics as well.

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#13 2006-04-01 21:32:51

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

JohninCR wrote:

food coloring

I have a set to play with.

dave

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#14 2006-04-01 23:50:40

GM
Member
Registered: 2005-07-31

Re: Modded FE126e FE127e

JohninCR wrote:

Since I can't find dammar down here........

Greets!

Nobody paints there? No artists?

GM


Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.

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#15 2006-04-02 00:51:21

JohninCR
Member
Registered: 2005-08-10

Re: Modded FE126e FE127e

GM wrote:
JohninCR wrote:

Since I can't find dammar down here........

Greets!

Nobody paints there? No artists?

GM

GM,
I'm sure there are.  The closest I've found to dammar is Kammar, but that comes in an aerosol spray can.  The closest I can find to ductseal is something used for installing windshields.  I had to go to 5 hardware stores just to find moisture resistant yellow wood glue, which amazed me with the humid conditions 3-4 months every year.  I can't find bipolar caps of any type and zero inductors (at least I can wind my own inductors because I found magnet wire).  No sonotube, despite most houses being concrete construction.  No rigid fiberglass for room treatment, and the thickest rolled glass insulation I've found is only 3".  However, even McDonald's delivers, traffic laws are more like guidelines than enforced rules, labor is cheap so everyone has a full-time maid, and we even have internet via cable that is remarkably stable even with all service going through a government owed monopoly.

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#16 2006-04-02 00:59:17

westend
Member
Registered: 2005-12-31

Re: Modded FE126e FE127e

Since you've mentioned felt smile: where is good source of thicker felt? I was felt shopping yesterday and all I could come up with is 1/8" cloth. As to the layout of the damar on the cones, it looks like you have most lines in the cone from the dustcap to the surround intersected. If I remember the Tangband mods correctly, they were not symmetrical but had longer and shorter lines of dopant and that was to deal specifically with certain frequencies. Too bad the mod is not reversible or there was a slovent available to remove damar without effecting the cone paper. One could experiment with different arc sizes and shapes. Have you tried a driver with just puzzlecoat? And finally as to the color of the driver, I understand the reasoning but it's just not my cup of tea.

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#17 2006-04-02 01:44:08

Geek
Member
From: Rosedale, BC, Canada
Registered: 2005-11-09
Website

Re: Modded FE126e FE127e

You can get 1/2" in fabric stores. They're used in utility blankets.


-= Gregg "t3h GeeK" =-
http://geek.scorpiorising.ca
"Ratings are for transistors, tubes have guidelines"

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#18 2006-04-02 01:48:18

westend
Member
Registered: 2005-12-31

Re: Modded FE126e FE127e

Geek wrote:

You can get 1/2" in fabric stores. They're used in utility blankets.

Thanks, I will tailor my felt shopping to the utility angle.

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#19 2006-04-02 02:58:55

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

I've only done 1 pair of FE127 and one pair of FE126.

dave

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#20 2006-04-02 04:00:02

Geek
Member
From: Rosedale, BC, Canada
Registered: 2005-11-09
Website

Re: Modded FE126e FE127e

westend wrote:
Geek wrote:

You can get 1/2" in fabric stores. They're used in utility blankets.

Thanks, I will tailor my felt shopping to the utility angle.

Just thought of another place - a tack store. I recall using thick felt pads under horse saddles.


-= Gregg "t3h GeeK" =-
http://geek.scorpiorising.ca
"Ratings are for transistors, tubes have guidelines"

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#21 2006-04-02 19:42:07

chrisby
Member
Registered: 2006-01-30

Re: Modded FE126e FE127e

Dave:

Had a second set of ears today (Frank) sit in on a short session, rotating all 4 speakers (Fonkens with modded 127s, stock  FE108ESigmas & 126s in  "that horn", and the modded 126s in the A126 with stop-sign baffle)   

wanna guess the order of finish?

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#22 2006-04-02 20:39:30

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

A126, Fonkens, FE108s, FE126?

dave

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#23 2006-04-02 20:55:04

planet10
Member
From: Victoria BC NA Sol 3 Milky Way
Registered: 2005-07-28
Website

Re: Modded FE126e FE127e

And if that isn't right then:

FE108s, A126, Fonkens, FE126?

dave

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#24 2006-04-03 01:51:59

westend
Member
Registered: 2005-12-31

Re: Modded FE126e FE127e

C'mon Chris, what was the outcome smile?

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#25 2006-04-05 12:33:01

chrisby
Member
Registered: 2006-01-30

Re: Modded FE126e FE127e

OK:

1) A 126 (modded drivers - larger CC)
2) top secret design BLH *  FE108 (stock)
3) same as #2 with FE126 (stock)
3) Fonken (modded FE127)

Of course while includind the stand, any mini size enclosure like the Fonken occupies approx the same net floor space, they don't require quite the same critical placement (vis a vis corners etc) as the rear mouth horns designs listed.


* secret my ass,  these were just two pairs of identical Buschorn MKI cabinets (originally designed for an 83mm driver)  increased in height to accomodate the larger Fostex drivers.

Last edited by chrisby (2006-04-05 12:33:53)

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