I'm the original owner of a pair of 1980 La Scalas. All original equipment, never been touched. I've been reading a lot about what many say is the need to update the crossovers or at least the capacitors. And others who advocate replacing the tweeters and midrange horns. Now the speakers sound just fine to me, as fine as ever. But they're almost 40 years old and I know nothing lasts forever. So how does one know whether these types of repairs are necessary? What do the Klipsch engineers recommend? Thanks.