Cheap fullrange project

[planet10]

Originally posted by arcturus
I wonder that could white PVa wood-glue

Puzzlecoat is a close relative of white PVA glue & often used as a substitute. You might have to thin it just a bit.

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...

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

[arcturus]

Hi,

I'll try to apply a bit of white PVA into the whizzer cone...let's see what happens!

What do you think about the epoxy glue? At least it is super-tough. Might be a bit more difficult to apply to the cone, though.

[planet10]

Originally posted by arcturus
I'll try to apply a bit of white PVA into the whizzer cone...let's see what happens!

do the whole cone...

What do you think about the epoxy glue? At least it is super-tough. Might be a bit more difficult to apply to the cone, though.

I've tried lots of things -- i can't see using expoxy thou -- unless you could get some that is really thin.

dave

[arcturus]

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.

[planet10]

Originally posted by arcturus
I applied some water-thinned glue into the cones, and the result is good!! Perhaps these drivers have some potential afterall!

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