One last caveat I might add regarding vintage or classic speakers is that upgrading components with modern replacement parts could reduce their resale value. I have seen the effects of this practice with some otherwise vintage tube gear, where modern caps and wires had been substituted wholesale for the original, still working, classic parts, changing but not necessarily improving the voice of the gear - and seriously impairing its market value. Personally, I appreciate keeping true classic gear close to original (it would be like installing a breakerless distributor in an old AC Cobra), but if that is not an issue to you, by all means modify. However, a fifty-year old K-horn with Cardas binding posts, Hovlands and silver Alpha core inside won't fetch as much as a good working original at resale time, IMHO.