This is an excellent question. I had a pair of Celestion Kingstons whose aluminum dome tweeters were exposed. Two nephews visited and damaged the tweeters, one much worse than the other. I was pretty heartbroken, because Celestion was out of business by then. I waited a couple of months before I had the heart to listen to them, and surprise, I couldn't hear a difference.
Had them for years after that, not using them and trying to sell them with no luck. I finally found an interested party, a British gent who had connections with one of the speakers designers in Ipswich and could have it repaired. He had previously owned a pair of them for years and knew them well. When he got them home, he emailed me and said that he couldn't believe that they sounded fine to him, just as I had told him.
Yes, you would think that a badly damaged metal dome would sound terrible, but apparently that's not always the case.
Had them for years after that, not using them and trying to sell them with no luck. I finally found an interested party, a British gent who had connections with one of the speakers designers in Ipswich and could have it repaired. He had previously owned a pair of them for years and knew them well. When he got them home, he emailed me and said that he couldn't believe that they sounded fine to him, just as I had told him.
Yes, you would think that a badly damaged metal dome would sound terrible, but apparently that's not always the case.