Double sided membrane and a tune (ugly setup)

I was playing with double sided membranes for the past week.
and finally i thought lets use my long 100mm magnets and see if i can make a mid range small enough to keep dispersion under control.

direct to tune ? here: https://youtu.be/wCa1aXMxR38?t=559
Music played : Riltons Vanner - Schack matt

i wonder what would happen if i go thicker foil. i imagine top end will drop but thats not a big deal, since it is not playing any, maybe QTS rises.. witch might be nice when used in OB.... or use a horn... hmm or or or and ifs... there is to much to try.