Where does “quack” come from? I'm getting a sound fairly close to strat quack with my MIM '69 Thinline RI. I don’t hear it while using the neck pickup and I don’t hear it when using the neck pickup but put the switch in the middle and there it is. I suppose some kind of filter is created by combining the two pickups but I am hoping someone can fill me in on the details. I’d also like to know in what frequency range “quack” lives. Thanks. Inquiring minds want to know.