I am re-foaming jbl 125A speakers.
One is already finished and it is perfect (there is no friction when raising or lowering the cone)
The second already has the new foam attached to the cone (but not yet to the basket) I am holding it with many "tweezers" to do the tests before sticking it.

the thing is this: it seems perfect when you move the cone down, but when you move it up it always rubs. This happens with any method of centering (battery, 30 Hz and manual).

The speakers (the boxes) are not "sisters" they have different serial numbers among other things, so they may have had different "care" and are not in the best condition.

any ideas?

I think the voice coil is made of paper and could be in poor condition from having been stored in damp places.
open the dust cover and see what happens? can be detached with toluene instead of cutting

thanks and sorry for my english from google translate