On Oct 15, 2:36*am, "N_Cook" wrote:
Anyone aware of a site of such tips for renovation.
About 50 years old. Looks as though the card of the cone hase weakened with
age, probably like the paper of books goes brown and crumbly over time.
Looks as though the central cone area probably has failed to resist the
returning force of the periphery and the spider and has buckled torsionally
but not split in that inner zone ,one or so inches, from the voice coil join
and radially out.

If it actually works, and just the paper is going bad, try spraying
the cone with an aeresol(sp) spray varnish, a little at a time until
you get the stiffness that you think it should be. If the flexible
portion around the perimeter is going, a very thin layer of spray
adhesive may hold things together.