[Phlogiston]

OK, this takes a little patience and a soft touch.

The challenge is to find which side the rub is on.

Loosen the screw in the center of the speaker. In this speaker that paper thing in the center is a spider. Use you fingers to gently move the cone in and out listening for the rub. Gently move the cone in the direction that makes the rub stop. Hold the cone in place and tighten the screw in the center. For your first try, this might take a little trial and error.

Notes: The cone will move pretty easily and does not have to move much to clear or MAKE the voice coil rub. The cone is old paper, be careful not to rip or put a finger through it. Sometimes these noises are made by foreign objects in the gap. When the screw is removed the cone will move much more (in and out) than normal. Lay it on a table face down and gently move the cone in and out. Crud and dirt will often fall out. Blowing lightly with "canned air" NOT an air compressor hose, might help but usually stuff just falls out. Your speaker looks good but sometimes this stuff is rust on the pole piece. Sometimes enough will clear to cure the noise sometimes it takes removing the whole cone. Again BE GENTLE.