My own take on Air Motion Transformer

[NV&H]

OK, here's what I'm working on. See image. 32awg aluminum wire coil. Very thin mylar backing and, as you can see, a "surround" made of very thin packing foam sheet. This thing will be slid into a 2"x1"x2" >1T gap with the "surround" glued to the magnet surfaces on each side. The non-corrugated section will simply be folded out of the way. Because of the direction of current flow in the gap, the magnetic flux lines are 90 degrees out from what I see in Heil's and most other designs. This gets rid of the "storm drain" looking structure in front of the ribbon you see in other designs. I hope to get sound in the next few days. Should be able to run it full range. The magnetic assembly has already been built. Just takes time for the "surround" glue to dry.

 

[srinath]

I dunno which way your wirs are running relatove to the pleats ... but the heil and I recently dissected one, has magnetic lines of force going away from you, wiring running up and down in front of you - current running up 1 wire, down the other etc with each wire on adjacent sides of a pleat ... and when you run current through it, they come closer in 1 pleat, and go further apart in the adjacent pleat, like an accordion.
Sound is compressions and rarefactions in air, and it directly makes those in the air.
Cool.
Srinath.

 

[godfrey]

This thing will be slid into a 2"x1"x2" >1T gap

I'm interested to see the magnet structure. Must be a monster!

 

[NV&H]

I dunno which way your wirs are running relatove to the pleats ... but the heil and I recently dissected one, has magnetic lines of force going away from you, wiring running up and down in front of you - current running up 1 wire, down the other etc with each wire on adjacent sides of a pleat ... and when you run current through it, they come closer in 1 pleat, and go further apart in the adjacent pleat, like an accordion.
Sound is compressions and rarefactions in air, and it directly makes those in the air.
Cool.
Srinath.

The current runs 90 degrees out from what the Heils do, so that's why I had to arrange things such that the magnetic flux lines are also 90 degrees out from what the Heils do. It wound up working nicely but then some toe-nail clippers got to near the gap and got sucked in. Destroyed the ribbon. Oh well, back to the drawing board.

Yeah, the magnetic structure is comprised of eight 2"x2"x1" magnets. The way I have them arranged, it's rather compact. The whole assembly is 5"x5"x2" with a slot opening where the flux is concentrated that is 2"x2"x1".

 

[srinath]

If the wires run side to side, but magnetic lines of flux go away from you then the wires will get pushed up and down. That can make its own heil like sound. Anyway put pics up. I have a destroyed diaphragm too from what could have been a screwdriver.
Cool.
Srinath.