I would just like to say again now that I have had the supertweeters for a few weeks, that the sound improvement in my Quad 989’s is superb, a great combination!
I have had just decent quality speaker leads to the Quads and have been waiting for the right opportunity to try something better, so when I tried your cables that come with the tweeters, first with them directly connected back to the amplifier (instead of piggy back from the spkrs) and was astounded at the improvements, making the tweeters even more fantastic, it also told me that my spkr leads must have been very average, so I moved the spkrs closer together so that I could hear them connected with your tweeters cables and was duly blown away by an incredible improvement, they were now the most transparent, detailed, natural, open, balanced, uncoloured sound I have ever heard come from them, and this without your tweeters helping them for the moment!