I'm refoaming a set of 125A woofers from Decade 36's. Among the good information that Gordon W gave me in this regard was the following:
"...[use] the "30Hz method" (ie, play a 30 Hz test tone through the speaker while the glue is drying, and make sure it's centered (ie, not rubbing) correctly- it'll usually want to center itself, due to the influence of the test tone) to insure that the coil is centered. ..."
I'd like to do things this way, so that I don't have to cut the cap, etc.
Two questions:
1. When I try to press evenly on the cone of either woofer to make the coil (?) move in and out, it seems to rub almost every way I push it. (Rubby, skretchy sounds.) I tried this with some other woofers at a local recycling depot, and most of them seemed to have much more tolerance.
Is it possible that something has worn out inside the coil, and that there are particles of some kind impeding smoothness? (And, if so, are the woofers just shot; or, is there some counterpart of WD40 to smooth things out?) Or are these just adjusted to a very narrow tolerance?
2. And, come to think of it, why aren't the coils going to lose their centeredness when I stand them up, with the coil moving horizontally, rather than vertically?
Thanks for any information.