I inserted Taket Batpro 2 supertweeters in my main system with my Daedalus Argos V2s. As others have said, they have a positive SQ audible effect across the frequency range. I have them at the front edge of the top if the cabinet centered. I’d suggest that you research ones that allow you to adjust their sensitivity range to align along the line of your main speaker's sensitivity
@emaillists - the Enigmacoustics Sopranino is still available