Diff. between Soliloquy "i" series and older type

The drivers were proprietary, as far as I could determine. There are a few tweeters out there with the same 110 mm flange and what looks like the same bolt configuration but I don't know if it would be possible to find a reasonable sonic match to the originals.

I'm not sure whether it corresponded exactly with the addition of the "i" designation but earlier versions of the SAT 5 and the 5.3 had soft-dome tweeters and the "i" versions had aluminum tweeters. I don't know about differences in the construction or crossovers.

Yes, I don't know about the 6.2i's but the later 5's definitely had aluminum tweeters. I just had to replace a bad tweeter in my SAT 5's and the only ones still available were the aluminum ones.

I bought the replacements from Underwood HiFi. He had bought some of the remaining stock when Soliloquy went out of business and is the only source I could find. I don't know if he has any more, though, there have been other threads about this and a lot of people have asked where to get them.