You made a very nice ribbon really good.
But with the iron you wil get a lot of troubles because of the back chambers.
That will generate very large resonates visible in the frequency measurements.
The only way to solve that problem is to fill the back openings complete.
But the problem of damping the back of the ribbon that it sucks the liveness out and it sounds more dull than a open back.
I made something similar al long time ago.
Rob
But with the iron you wil get a lot of troubles because of the back chambers.
That will generate very large resonates visible in the frequency measurements.
The only way to solve that problem is to fill the back openings complete.
But the problem of damping the back of the ribbon that it sucks the liveness out and it sounds more dull than a open back.
I made something similar al long time ago.
Rob
Made extensive tests on that in prior projects. There are very small differences in frequency response in closed and open versions. I am not a fan of dipoles. At least not if there is a wall behind the driver. Will put a first layer with very open aquarium foam, behind that pretty loose stone wool to absorb the back waves. Will add stone wool increment it by weight and the measure frequency response and distortion until.i get an optimum. I am pretty sure that i can get more than 100db/ 1m with less than 1% above 300 Hz and less than 0.3% above 600Hz.