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/tlinespeakers/FAL/box-plans/P10-FR125-bipole-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.?
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/tlinespeakers/FAL/box-plans/P10-FR125-bipole-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.?
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.
RTF said:
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
Attachments
type said:
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
RTF said:
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
RTF said:
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
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.
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.
Jet-Lee said:
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.
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
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-
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-
Jet-Lee said:
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