Originally Posted By: AVB
I would do it, but I don't think that I would invest that much in them. I would go to parts express or ebay and pick out some drivers and crossovers.
+1
Stick with Parts Express. They have quite a bit of advice and reviews to help you as well as excellent free technical support. If you call them they should be able to recommend the appropriate components for your speakers.
Otherwise, do some research and calculations, pick the woofer drivers based on the characteristics of the cabinets, they MUST match the cabinets if you expect to get good sound from them. If memory serves, the Kappa 6.1's used a base reflex (ported) enclosure that uses rather oddly designed/shaped ports, this is going to complicate your woofer choice and you may need to modify the ports to get them to properly match the woofer drivers that you choose. You could even seal the cabinets and make them into acoustic suspension speakers if you use the correct woofer drivers. Also, the crossovers in the cabinets likely won't work for your replacement drivers, so the replacement crossovers you choose MUST be a match for the mid range and tweeter drivers that you choose.
Don't worry about how inexpensive the drivers are that you choose, you don't have to spend a fortune to get good sound if all the components match with each other and cabinet properly.