Home built 1" dome tweeters, with step-by-step pics

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Hello all, here are some photos I have put together of some tweeters I have been working on, for you to have a look.
I designed my own top-plate, and I took the centre pole piece from a pair of cheap Aiwa speakers. The grey colour is galvanising zinc paint. I had an engineering shop put a chamfer on the rear of the top plate, to concentrate the magnetic flux over the coil, its slightly visible.
The first picture shows the top plates, then gluing a thin walnut veneer onto the front surface. It also shows the magnets without the top plate, and you can see I drilled out the pole piece, and I also lined the interior of the gap with fiberglass. The ceramic magnets came out of a celestion and a phillips tweeter (identical dimensions). The pole pieces are from a pair of cheap Aiwa woofers.

The second lot of photos show the balsa wood 'donuts' I carved out of balsa wood with a scalpel (prior to sanding), these go behind the dome to help damp the dome and help reduce any resonance. In the bottom half it shows all bits of the tweeter to go together, and then it shows the top plate glued on, with a bunch of aluminium shims to keep it all centered.

Last photo shows the wires being soldered on and the dome being attached, with the balsa wood ring glued on. The red stuff in the middle is finely chopped wool fiber I glued into the pole piece vent to reduce any unwanted reflections, and the last pic shows the finished tweeter. Well, almost finished. Next step is to make a rear chamber, but all the fiddly stuff is done.
And having listened to them, I am very happy so far. Brilliant top end, very nice and clear. And when played connected with no crossover, they have a very smooth sound, with surprising bottom end for a 1" dome. For a first project of this sort, the results have certainly been very encouraging.

I am unsure what make the domes are, I bought a bunch of them from a friend as spares for replacement, and I thought I would design and build something around them. Once I make the rear chamber and they are complete, I will take measurements and see what they look like on paper. That's not as important as how they sound though.

Just thought I'd post up the photos and explain them so you could see what I have been working on, and I would be keen to hear any thoughts/suggestions you may have.
 

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Nice work flyingtele.

Not the kind of thing that is attempted very often I think.
Very inspiring to see the results.
I have toyed for a while with trying a diy cap. mic. capsule (and that doesn't even have any moving parts).
Good to see this kind of 'micro' diy work.
Keep us posted.

Cheers

Simon
 
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