Diy AMT

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Hmmmmmm.

I am not satisfied.

With the freq. responce.
My latest measurements are without the small horn.
Drops too much at high freq.I might not hear it though. 58 year old and a history with noisy machines.
My next move is 10my alu , 12my mylar (3M tape) , 7-8mm deep ,double coil.
My present amt's ,are 3 diaphragms: 80x32x9mm, in series.
My next one might be 2-3 diaphragms 89mmx32x 7mm.double coil ,in parallel.
Btw. I might do my measurements in a large baffel.

Bernt
 
I have just made a drawing for 3 coils:
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I am listening to 2 different AMT's.Both with 2 diaphragms, 7mm deep.and 10my alu 12my. mylar.
One with two dual coils app.6 ohms in paralel 3 ohms in total and
One with two single coils ,app.1,5 ohm in series , 3 ohms in total.
They don't sound alike.
The one with two double coils sounds "softer"
The other a bit Harsh at the top .
Have to measure them too.

Bernt
 
There is not much musical information above 13 000 hertz.

Yes I know that there are higher harmonics and that they can be heard.

But try a limit on a system at this point 13 kilohertz and tell me directly what is missing.

You need the correct program materials to even begin to notice a difference.

So as long as you are OK up that high and roll off gradually you should be OK.

That Bernt can hear the difference says right away that there is a difference.

Possible the three coil pattern could make the bridge between what he likes and does not like in the sound.
 
Just cut and folded diaphragms, and baked them for 20min. at 200 dg.
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Traces are tight 0.9mm. space and 1.4mm cunductor, 2,7mm space for bending.
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alutape is adhesive and sticked to 15my mylar,Here withdrawn from the cutting mat from the silhouette cutter.

Bernt
 
First one sounds best.
Top a bit agresive on the second.
The first 10my/12my is the lightest ,and has a good sensivity in spite of it's higher resistance.Wont take much power though.Only 2mm traces 10my.

Bernt

so not allot of power handling but hell if they are so efficient its not needed :)

i am playing around with paper amt's not as efficient as mylar ones but a hell more simple to construct. instead of clean pleats mine is folded like this /\/\/\/\/\/\

I have major problems getting my amts out of the jig, i keep having one side bulging out or stucking to the jigg, witch then result in total failure :(
 
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