Brad , these came today, I will say these work , I have not yet use all the different taps yet to find out which one works the best with my set up, these work by changing the impedance of the speaker so the amp will work better, so far the sound is better bass { controlled } mids are better than before, treble sounds clearer to me but the same. I will not be able to get to all the different taps in a few days it might take a few weeks,but these do work. the web site is zeroimpedance .com I will keep you up to date as much as I can about this Zero thing . Greg