Silverline sr 11

I have two pairs of these very wonderful speakers, one has a Kirksaeter tweeter(marked so) the other a plain tweeter( no markings). Does ayone have an explination for this? I might say of the Siliverlines I have had: Minuets, SR12's,... the 11's really knock me out and the Minuets are the best very small speaker I've heard, esp with a sub., for what it's worth...

Do they sound different? I know that the owner is also the designer. Maybe he ran out of one tweeter so he changed it or it's an actual design change.