@audiolabyrinth - the way to think of a SuperTweeter is that it is to tweeters as a SubWoofer is to Woofers i.e. it complements and extends rather than replaces. The Sopranino, like the Townshend and the recently introduced KIT HIT (https://www.monoandstereo.com/2018/04/new-kit-hit-super-tweeter-from-japan.html#more) operate in parallel with your existing speakers. That is you run a short speaker cable directly from your speaker connections to the terminals on the SuperTweeter. The SuperTweeter then comes with adjustments for crossover and level so you can match it to your existing speakers - generally like subwoofers the rule is if you can hear it operating you’ve got it set too high (e.g. level too high or cross over too low)
Some other SuperTweeters require their own mains power and this adds to the complexity.
Some other SuperTweeters require their own mains power and this adds to the complexity.