Speaker repair
If the matial around the edge of the woofer between it in the cabinet is the problem, it should be a pretty easy and relatively inexpensive repair. It is common for the foam surrounds to deteriorate over time. If the woofer itself is damaged it will be more difficult and expensive to find a replacement.
I haven't heard the Kappa 7s but they are high end speakers and I suspect that a comparable replacement would be in the $1-2k/pair price range.