Timn8ter said:
Dammar is much stiffer when dry than puzzlecoat... so along with the 98 cent "brace" seems to bring the whizzer into control -- that is the trick i 1st tried on the blue & yellows (you got to hear those didn't you?).
(As a reference, that speaker project was a 12 euro one (including shipping)).
dave
Greets!
If you only changed Re, Sd in the sim I did, then if you use the formula I posted you will get the correct BL = 4.1281 N/A and the shape of the FR is unaltered since it's defined by Fs, Vas, Qts, so if you inputted the info correctly then this is just one more reason I know of not to recommend/use WinISD. Whether the plot's even close to correct is another matter, but with a high Q driver the cab only controls a very narrow BW so in a pipe it's not a big deal since the vent can be critically damped.
Yes, with no stuffing, it's quite the little 'boom tube'.
Loosely stuffing it with ~4-5 oz of polyfil along its entire length should smooth it out quite a bit, though without the other tweaks it will probably still have the undamped whizzer 'shout', breakup modes, and reflections back through the cone typical of cheap FR drivers.GM
kneadle said:
I guess cheap is a pretty relative term, but a definition of say <$25 is probably appropriate (this sweeps up all those TB & RS drivers and includes the Pioneer B20). cheap FR is one step above the $2 FR which is defined as less than $10/pr (usually found at garage sales -- note: that pair of Goodmans Axiom 201s found in the totally beat cabinets is excluded).
dave
http://www.t-linespeakers.org/FALL/2buck.html
An externally hosted image should be here but it was not working when we last tested it.
Hi,
I wonder that could white PVa wood-glue or 2-component epoxy glue be used to make the cone(s) stiffer?
What do you mean with the "98 cent tweak"?
I've tried to attach some pieces of foam inside the "whizzer" and between the main cone and the whizzer. Making not much difference...
"Whizzer shout" is just the right term to describe the sound. It's really harsh sound.
If the sound doesn't come better after some simple tweaks, I think I'll start looking for some 3" or 4" Tang-Band drivers... I see that they're also not very expensive but perform a lot better (what I've read on the WWW).
Timn8ter said:
planet10 said:
I wonder that could white PVa wood-glue or 2-component epoxy glue be used to make the cone(s) stiffer?
What do you mean with the "98 cent tweak"?
I've tried to attach some pieces of foam inside the "whizzer" and between the main cone and the whizzer. Making not much difference...
GM said:
"Whizzer shout" is just the right term to describe the sound. It's really harsh sound.
If the sound doesn't come better after some simple tweaks, I think I'll start looking for some 3" or 4" Tang-Band drivers... I see that they're also not very expensive but perform a lot better (what I've read on the WWW).
arcturus said:
Puzzlecoat is a close relative of white PVA glue & often used as a substitute. You might have to thin it just a bit.
The 98 cent tweak is the foam between the whizzer & the main cone...some people have found that this trick kills the dynamics, but there is a sweet spot where the foam is supportting/terminating the edge of the whizzer, and providing some damping for the cavity, with not enuff & too much on either side of the sweet spot. I find that its effectiveness workd well in conjunction with stiffening the whizzer -- dammar will stiffen it a lot more than puzzlecoat/PVA and therfore tend to require it to have more damping. I will also add a ring of puzzlecoat on the backside top edge of the whizzer to further terminate it.
dave
Attachments
Hi,
I applied some water-thinned glue into the cones, and the result is good!! Perhaps these drivers have some potential afterall!
There's a lot less of that annoying midrange-shout, actually down to acceptable levels for me (the targeted audience)
There's also some more bass in the sound when I attach the driver into the testing T-Line (=cardboard tube). Some of the T/S parameters have propably changed a bit....i think to the better way.
I'll see if I could measure some of the "enhanced" parameters, i found a loudspeaker design book from library, it has a guide how to measure driver parameters with a computer, amplifier and multimeter.
I applied some water-thinned glue into the cones, and the result is good!! Perhaps these drivers have some potential afterall!
There's a lot less of that annoying midrange-shout, actually down to acceptable levels for me (the targeted audience)
There's also some more bass in the sound when I attach the driver into the testing T-Line (=cardboard tube). Some of the T/S parameters have propably changed a bit....i think to the better way.
I'll see if I could measure some of the "enhanced" parameters, i found a loudspeaker design book from library, it has a guide how to measure driver parameters with a computer, amplifier and multimeter.
arcturus said:
I usually do at least 2 coats
There's a lot less of that annoying midrange-shout, actually down to acceptable levels for me (the targeted audience)
My speculation on why here -> http://www.t-linespeakers.org/design/tweeks.html
There's also some more bass in the sound when I attach the driver into the testing T-Line (=cardboard tube). Some of the T/S parameters have propably changed a bit....i think to the better way.
Fs should go down (with the increase in mass) & the Qts up... in my experiments not much.
dave
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