Then I teated the surround with Aleene’s® Flexible Stretchable™ :
That was more change than I had expected--and for the better! So I tried again:
Notice that the rim resonance is down 6dB from the original after just 2 treatments! I though it could get no better, but figured what the heck, throw another slab on. This time I also added some yellow glue around the rim of the cone:
Another improvement so I did the same again:
OK, so in many respects this one is starting to look worse. I figured there was still a change and I should now just see where it goes. I didn't want to see worse again, so I didn't add any more yellow glue to the rim and damped the whole cone.
and yet again:
That's where I stopped for a listen.
I'll follow this up.