| chrisb |
I treated the walls of both my monopoles and bipoles with a thin layer (1/2") of cotton or wool felt.
The rectangular shape behind the magnet to brace the drivers to the cabinet (monopoles) or each other in the case of bipoles.
It should be as tight a fit as you can make without warping the rather thin stamped metal frame. A slightly loose fit to the magnet with some duct seal or Blu-tack.
Take a look at the referenced sketch for a more detailed look at this bracing method.
http://homepage.mac.com/tlinespeake...le-MLTL-map.gif
As for density and location of fill material, I believe Tim answered that previously, but since this thread is quite extensive, perhaps he could refresh our memory.? |
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| Timn8ter |
| Common practice with TLs is to place the stuffing in the upper 2/3 portion of the cabinet. It can be suspended by the bracing or you can create a "pillow" using "cheese cloth" or grill cloth. With the down-facing port it would be advisable to contain the stuffing with something. It will surely work it's way down over time otherwise. |
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| RTF |
| So is the brace placed horizontilly covering the width of the back panel? or just covering the width of the magnet? ie looking down into the cab will the brace form a U shaped negative space? or a rectangular one? |
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| planet10 |
| quote: | Originally posted by RTF
Is there something significant about the rectangle behind the driver? is that a physical part of the design or just a visual reference of some sort? |
As drawn it was intended to be a circular dowl between the magnets (or the magnet & the back in the case of the monopole. In practise this turned out to be clumsy. More work, but also more effective id a rectangular holey brace with tight fitting magnet cutout(s).
I have started revisiting these designs and as my penchant of late, any excuse to do a sketchup visualization so eventually more up to date drawings will appear. for now i will attach a visualization of Mileva (for the FE127) that illustrates a full length holey brace,
dave |
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| planet10 |
| quote: | Originally posted by RTF
So is the brace placed horizontilly covering the width of the back panel? or just covering the width of the magnet? ie looking down into the cab will the brace form a U shaped negative space? or a rectangular one? |
The brace needs to run in the same direction as the line -- in this case vertically.
dave |
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| RTF |
| Ok I think I have it, thanks for the help. |
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| type |
| I have not read the entire thread so maybe this was already addressed. I wonder if applying damar, puzzle coat, etc... adds weight to the driver cone and if this added weight can affect the driver's sensitivity. |
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| planet10 |
| quote: | Originally posted by type
I have not read the entire thread so maybe this was already addressed. I wonder if applying damar, puzzle coat, etc... adds weight to the driver cone and if this added weight can affect the driver's sensitivity. |
Yes it does... with a FR you want to add as little treatment as possible, so effect is minimal.
I am just about to do a batch of FE127... but the data collected for a dozen FE126s (modified as per my formula -- a damar pattern followed by 2 thinned coast of mod-podge), showed a decrease in Fs of 3.7 Hz, and an efficiency decrease of 0.46 dB. Vas decreased 3.3% and mass went up 5%. All other parameters were essentially unchanged. Even the larger values are potentially within the experimental error or even just subject to different weather conditions.
dave |
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| planet10 |
Note that (IMO) the improvement in the driver from the mods i do significantly outweigh any downside.
If you are doing them yourself, it certainly is possible to go too far.
dave |
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| Ray Collins |
The Risk is Well Worth the Gain......Which is Significant.
Ray |
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| RTF |
| Where does one find this 1/2in felt lining, the only stuff I've found is quite thin, I've checked the usual places Home depot, linen stores. |
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| planet10 |
| quote: | Originally posted by RTF
Where does one find this 1/2in felt lining, the only stuff I've found is quite thin, I've checked the usual places Home depot, linen stores. |
Some of the supply houses will have it (ie McMaster-Carr (sp?) an auto apolstry shop might (you want felt or cotton (ie natural) and not synthetic fibres. I so far have not had to look further than the stuff that i have salvaged out of many old speakers (Norescos, Sansui are 2 good sources), but that is running near the end so we have started looking ourselves.
dave |
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| Ray Collins |
McMasters-Carr is a bit expensive for felt....let us know if you make a Frugal Find.
Ray |
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| planet10 |
| quote: | Originally posted by Ray Collins
....let us know if you make a Frugal Find.
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:)
It is my mission ...
dave |
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| Ray Collins |
Go Forth My Son...
Ray |
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| RKH |
| quote: | Originally posted by RTF
Where does one find this 1/2in felt lining, the only stuff I've found is quite thin, I've checked the usual places Home depot, linen stores. |
This might not be the same stuff, but it certainly looks like it might fit the bill... I have some 1/2" thick carpet backing/padding that looks mostly like felt. (Not the nice padding used for high-end installs) I got it for naught as a off-cut, remnant. Check your local carpet/flooring store.
Just an idea.
Ryan |
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| Jet-Lee |
1. In regards to the mods for the FE126E, notably the Dammar on the 9mm and 17mm "rings" on the cone, is the aerosol Kamar a suitable substitute(when used with a template) when there is an absence of Dammar?
2. When putting on the diluted puzzlecoat, should it soak into the cone or not? I've read plenty of discussion and seen pictures of both, but haven't found a definitive answer of sorts.
I'd like to give this a shot on some 126E's I have. |
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| planet10 |
| quote: | Originally posted by Jet-Lee
1. In regards to the mods for the FE126E, notably the Dammar on the 9mm and 17mm "rings" on the cone, is the aerosol Kamar a suitable substitute(when used with a template) when there is an absence of Dammar? |
I find the thot of using an aerosol kinda scary... if that is all i had i'd spray it into a little container and then paint it on. I'm not familiar with Kamar, but the purpose is to change the cone characteristics at those points. The damar soaks right thru the cone.
| quote: | | 2. When putting on the diluted puzzlecoat, should it soak into the cone or not? |
The puzzlecoat penetrates a miniscule distance into the cone, most of it sits on the surface. The 2nd coats sits on top of the first coat.
Use as little as you can to coat the cone, and work fast. I find the PK is almost setting up by the time i'm all the way round.
dave |
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| Jet-Lee |
Thank you Dave!
Several people at Hobby Lobby said that Kamar is just Krylon's aerosol Damar, I grabbed a can. Boy-howdy does it soak into whatever you spray it on, including skin!
I'll see here in a little bit if it's possible to puddle it in a container-of-sorts to 'paint' onto something.
What does the puzzlecoat do, exactly?? I understand the Damar silences(or reduces) the modes at the 9mm and 17mm rings, but I still don't understand the puzzlecoat except for adding color to it to color the speaker.
Thanks again,
-Lee- |
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| planet10 |
| quote: | Originally posted by Jet-Lee
What does the puzzlecoat do, exactly?? I understand the Damar silences(or reduces) the modes at the 9mm and 17mm rings |
The puzzlecoat reduces the self-noise of the paper cone... and it does this without significantly stiffening the cone (so as to not loose to much HF -- and the need to use it thinned and as little as possible and still coat the cone). It also makes the cone a bit more opaque to reflections thru the cone.
http://www.t-linespeakers.org/design/tweeks.html
dave |
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| l0gar |
Hey everyone,
I'm thinking of buying a pair of Fostex FE126Es or FE127Es to play around with in an open baffle design. However, other than just hunting around for cool designs and reading opinions, I've never built speakers. A full-range speaker should be easier to start with than something involving a cross-over right? Kinda a basic question, but I don't want to bite off more than I can chew.
Also, between the 126 and 127 in an open baffle I'm thinking the higher Q of the 127 is a better idea. I don't like the bumps in the higher frequencies though and I like that the 126 gets beyond 20khz. Thoughts between the two?
Thanks in advance. |
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| vinylkid58 |
| quote: | Originally posted by l0gar
I'm thinking of buying a pair of Fostex FE126Es or FE127Es to play around with in an open baffle design. However, other than just hunting around for cool designs and reading opinions, I've never built speakers. A full-range speaker should be easier to start with than something involving a cross-over right? Kinda a basic question, but I don't want to bite off more than I can chew. |
I used a jiffy OB for my FE127's to start the "break-in" process while I built cabs for them. Dimensions for the OB were roughly based on the JE labs design. BTW, they don't sound great in OB, not much bass and won't play to a decent level.
Both of these drivers are better in a box IMHO, FE126 in a horn and FE127 in BR.
Jeff |
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| chrisb |
| quote: | Originally posted by vinylkid58
I used a jiffy OB for my FE127's to start the "break-in" process while I built cabs for them. Dimensions for the OB were roughly based on the JE labs design. BTW, they don't sound great in OB, not much bass and won't play to a decent level.
Both of these drivers are better in a box IMHO, FE126 in a horn and FE127 in BR.
Jeff |
Jeff, you really mean an aperiodic vented or MLTL for the 127, don't you?
:cannotbe:
You should drop by for a listen to the Milevas sometime soon. |
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| vinylkid58 |
| quote: | Originally posted by chrisb
Jeff, you really mean an aperiodic vented or MLTL for the 127, don't you? |
Oops, did I say BR? Sorry, I forgot this is the "Reference Thread", I seem to be a little distracted today, must be the onset of summer or something.:D
| quote: | | You should drop by for a listen to the Milevas sometime soon. |
Yes, that sounds like a great idea. Pm me and we'll set something up.
Thanks!
Jeff |
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| planet10 |
| quote: | Originally posted by l0gar
I'm thinking of buying a pair of Fostex FE126Es or FE127Es to play around with in an open baffle design. However, other than just hunting around for cool designs and reading opinions, I've never built speakers. A full-range speaker should be easier to start with than something involving a cross-over right? Kinda a basic question, but I don't want to bite off more than I can chew. |
In light of an OB, either of these drivers need to be considered as mid-tweeters in a 2-way system. The Fe12x would be XOed no lower than 200-300 Hz (and preferrably actively.
dave |
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| SCD |
Hello Folks:
During the construction stage of the cabinets I was making for the FE127. I had the drivers mounted on an open baffle. The pupose of mounting on the baffle was to get a feel for the sound of the driver and to help break in the driver, stretch it a bit as it were. I am not sure about the correct technical term but the term that came springing to my lips was wow this really sucks. The sound was lifeless and thin. If I had not heard the drivers in a properly designed enclosure (Thanks Dave) I would have never used these drivers.
As Chris and Dave have indicated do not expect to much from the open baffle with these drivers. With a few strategically placed modifications to the drivers and a few of Dave's designs these little darlings really do shine, the OB method is for another project.
Good luck |
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| planet10 |
| quote: | Originally posted by SCD
the OB method is for another project.] |
I was going to mention ... if you want to get your feet wet with a reasoable but dirt cheap OB project, do have a look at used vintage drivers... for an expenditure of $10-$50 for drivers you can get something that can be quite musically satisfying for next to nothing -- you do need to be creative with sourcing baffles to keep the cost down.
A good example of this is the OB project below:
All of $10 for drivers. And the baffles were found on the side of the road for free... and then Scott (SCD above) turned them into OBs (he made the mistake of bringing his tools as we were cleaning up for the 2nd annual VI diyFEST).
I've had a series of drivers in them, and now we are going to install some unobtainium Korean OB FRs and auxilury 15" helper woofers and play with some of Lynn Olsen's baffle edge treatment ideas (i'm good for drilling hundreds of holes in the edges)
Choosing a set with unfasionablly high Q can give the illusion of decent bass even when the baffle/driver is hard pressed to support 100 Hz. A good example of more up-scale drivers are these Isophons (please excuse my pointing to one of my own active eBay auctions) http://cgi.ebay.com/ws/eBayISAPI.dl...em=280120483857 (these want a particularily slim baffle) or these Nationals http://cgi.ebay.com/ws/eBayISAPI.dl...m=280113550266. Q on the Nationals is maybe a bit low to give the best illusion of bottom -- they would need a wider baffle
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| SCD |
Yes that was a surpisingly good dsounding tailgate project. It is quite amazing what you can make when you have few "Audio-nut-bars" together and all the things needed to make an instant set of speakers. A couple of quick calculations,( what is the square root of 2 again?) a pencil, a drill, a jigsaw and before you know what happened those vintage Loyds drivers never sounded so good.
If I recall they started to sound even better as the sun went down. Not sure if that was due to the temperature drop or the lubrication. It was definitely a fun afternoon.
I am definitely looking forward to this summer. Should I bring my tools again? |
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| planet10 |
| quote: | Originally posted by SCD
Should I bring my tools again? |
In the words of Nelson Pass ... muhahaha :) |
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| chrisb |
| and don't forget the band-aids and polysporin |
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| chrisb |
| quote: | Originally posted by SCD
Yes that was a surpisingly good dsounding tailgate project. It is quite amazing what you can make when you have few "Audio-nut-bars" together and all the things needed to make an instant set of speakers. A couple of quick calculations,( what is the square root of 2 again?) a pencil, a drill, a jigsaw and before you know what happened those vintage Loyds drivers never sounded so good.
If I recall they started to sound even better as the sun went down. Not sure if that was due to the temperature drop or the lubrication*. It was definitely a fun afternoon.
I am definitely looking forward to this summer. Should I bring my tools again? |
*do you want to rephrase that to "intoxication"? |
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| ogorir |
| quote: | Originally posted by asoprs
vinylkid58,
Unfortunately my home depot and local hardware store didn't have ductseal. The art supply place had a varnish for paintings, it just wasnt damar (brand?). I think its prob. the same stuff, just wondered if anyone knew before I actually put it on the drivers.
tom |
I wandered over to this thread from the Frugal horn thread (which I stumbled upon looking for class AB+ tube output topolgy [a standard PP AB amp with a floating ground tied to the plate of a class A tube IIRC])
Anyhow, I'm thinking of buying/building a Frugal horn flatpack, and I had a couple of questions about modding the FE 126e's.
I also have some sources to get the materials that no one has put forth yet.
Dammar can be had from Dick Blick, along with decoupage (puzzlecoat)
Several Varnishes
http://www.dickblick.com/categories...#damarvarnishes
Mod podge:
http://www.dickblick.com/zz029/16/
also, Blick has 5lbs of non-hardening modeling clay for 7 bucks, which should work for the basket damping:
http://www.dickblick.com/zz332/32/
Unfortunately, Blick doesn't have thick felt.
But, a quick google search tells me the Felt People (who else?) do. I just sent out an email asking for samples. They have %100 industrial wool in 1" thickness, but they don't have prices listed. I'll post back when I hear from the Felt People.
This stuff might also work well to coat paper cones. It's very flexy PVA glue. Doesn't do what its marketed to (won't protect against stonechips) but, it might be the ticket for speaker cones.
its $25/gallon
http://www.strippablecoating.com/pr...hield_5720.aspx
Now, if I get this straight, we want the Decoupage to soak into the cone, right? My experience in autobody leads me to believe that thinning the stuff down 10:1 and spraying it on real thin will allow it to soak in more thoroughly. you can put an infinitely thinner coat on of anything by spraying it (provided its sprayable in the first place), but thats just my two bits.
What I don't entirely understand is whether the dammar is supposed to sit on the surface, or is it supposed to soak in also. presumably you've recommended dammar because its stiffer than the decoupage, but still flexible enough to not completely kill the frequencies it is effecting.
What I'm wondering is if dammar is really the best product, as there are a zillion different varnishes (or shellacs, lacquers, enamels for that matter). If it would be better if the spot varnish sat on the surface, shellac might be the best bet.
Thanks for the very interesting and thought provoking thread,
McGuire |
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| planet10 |
| quote: | Originally posted by ogorir
Now, if I get this straight, we want the Decoupage to soak into the cone, right? My experience in autobody leads me to believe that thinning the stuff down 10:1 and spraying it on real thin will allow it to soak in more thoroughly. you can put an infinitely thinner coat on of anything by spraying it (provided its sprayable in the first place), but thats just my two bits.
What I don't entirely understand is whether the dammar is supposed to sit on the surface, or is it supposed to soak in also. presumably you've recommended dammar because its stiffer than the decoupage, but still flexible enough to not completely kill the frequencies it is effecting.
What I'm wondering is if dammar is really the best product, as there are a zillion different varnishes (or shellacs, lacquers, enamels for that matter). If it would be better if the spot varnish sat on the surface, shellac might be the best bet. |
Last question 1st... there could well be something better than dammar for this task.
The Dammar soaks right thru the cone, The puzzlekoat mostly sits on the top soaking in only a tiny bit (binding the surface layer of paper fibres together)
dave |
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| ogorir |
Ok. Once I get one pair of 126's in good sounding order with the current techniques, I might experiment a bit and try different techniques/products.
Do you think it would be better if the puzzlecoat soaked in more, or not? (seat of the pants guess is fine my me, but you've had a lot more experience that I with modding speakers)
Also, has anyone seen 126's cheaper than $42.75 (from madisound)?
McGuire |
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| planet10 |
| quote: | Originally posted by ogorir
Do you think it would be better if the puzzlecoat soaked in more, or not? (seat of the pants guess is fine my me, but you've had a lot more experience that I with modding speakers) |
You want to put as little puzzlekoat on as you can and still seal the surface layer. Too much and you'll kill the top end (which unfortunately has been done)
dave |
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| dublin78 |
Hi
I am just completing my MT-TL monopoles (finally) with FE127E.
See: http://www.diyaudio.com/forums/show...8564#post528564
I am going to line them with felt as per thread instructions.
I am not quite sure about the stuffing though. I have two packs of Monacor MDM2 300g/m2, but I am not sure how much to put in the cabinets. Each pack contains two 630mmx330mmx35mm sheets.
Also, I have read that only two thirds (2/3) of the transmission line should be filled. Is this 2/3 of the whole cabinet (A), or the whole of the top half and 2/3 of the bottom (B)? This is my primary question. I think that I am there with the stuffing density, I am going to use a pack in each initially.
Please see photo for clarification. The photo shows a cross section of the cabinet. My port is built into the base. |
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| tpremo55 |
| quote: | Originally posted by Harderror
Ok, guys, my latest toying around, (I was bored today). This is the pioneer A11EC80. SOunded like **** when I first hooked it up. Now, 7 coats of diluted elmers and a phase plug which I manufactured this morning, as well as felt on the back of the magnet and UHU on the frame of the speaker to damp it, it actually sounds resonably nice. We used it in the home theatre tonight in the Fonken boxes and it really integrated well and shined in these enclosures. Not too shabby for an $11.00 driver. Here are a couple of pictures. |
Tom, would you mind sharing a little more detail on what you ended up with for a final setup on the Pioneer A11EC80s? I've got a quad of these sitting around and was doing some searching to get ideas. I was thinking of an MTM t-line, then a single driver bipole. Just playing around, but very interested in experienced recommendations.
Thanks! |
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| Harderror |
| quote: | Originally posted by tpremo55
Tom, would you mind sharing a little more detail on what you ended up with for a final setup on the Pioneer A11EC80s? I've got a quad of these sitting around and was doing some searching to get ideas. I was thinking of an MTM t-line, then a single driver bipole. Just playing around, but very interested in experienced recommendations.
Thanks! |
Wow, that was a long time ago. I haven't used those drivers in a long time. I ended up using them in the Fonken box for a long time. Then I built an MLTL for them that worked reasonably well. They are now just collecting dust though. I wouldn't build the MLTL I did either though because it was a modified TL from another design. It worked but not as well as I would have hoped. The one thing I can tell you is that this driver puts out a great deal more low end than the FE127 so any box the FE127 works in, this one will too, albeit with a bit more bass. I would opt for a Dipole if you have 4 of them. The harshness of this driver is bit of a pain to deal with. In the end, I sealed the cones (with elmers) be careful as too much will take away all high frequency. Used bluetack to damp the frames as these sing quite readily on this driver. Put a small ring of felt at the center of the driver (around the phase plug but not touching it) which calmed a couple of the peaks and of course I made and installed the phase plugs. The driver became my work system for a while (in the Fonken box) and it sounded quite good.
This driver was a fun project overall and I don't think you can go wrong messing around with it. Like I said, Dipole is probably the way to go.
Tom |
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| tpremo55 |
| quote: | Originally posted by Harderror
Wow, that was a long time ago. I haven't used those drivers in a long time. I ended up using them in the Fonken box for a long time. Then I built an MLTL for them that worked reasonably well. They are now just collecting dust though. I wouldn't build the MLTL I did either though because it was a modified TL from another design. It worked but not as well as I would have hoped. The one thing I can tell you is that this driver puts out a great deal more low end than the FE127 so any box the FE127 works in, this one will too, albeit with a bit more bass. I would opt for a Dipole if you have 4 of them. The harshness of this driver is bit of a pain to deal with. In the end, I sealed the cones (with elmers) be careful as too much will take away all high frequency. Used bluetack to damp the frames as these sing quite readily on this driver. Put a small ring of felt at the center of the driver (around the phase plug but not touching it) which calmed a couple of the peaks and of course I made and installed the phase plugs. The driver became my work system for a while (in the Fonken box) and it sounded quite good.
This driver was a fun project overall and I don't think you can go wrong messing around with it. Like I said, Dipole is probably the way to go.
Tom |
Thanks again Tom.
I've been more of a multi-way speaker designer than a single driver, but the fact that I have these speakers on hand has pushed me into a new area of research. I'm doing a lot of reading on mods to the cone and basket. I've made my own phase plugs in the past (for a Seas P17RCY) and have used plumbers putty on the basket. I've never coated the cone with anything...
Is there a recommended source of information with the benefits and drawbacks of the various coatings? I'm just getting setup with SoundEasy measurement (have the Behringer mic and MobilePre external card). So I may be able to trial and error some.
While I read a lot about people having high expectations for these drivers, I have noted that most of the efforts resulted in 'ho-hum' reviews. Has anyone been really happy with their design? Anyone try these to a liking in a ML-TL or other TL?
Thanks!
Todd |
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