<HTML>Thanks to those who have responded so far about this. I thought I'd better send an interim response, so you'd know I'm still listening. First, let me clarify what I know so far, and rule out a few things. I agree with Ron that this is definitely not a voicing issue, nor a termination issue. It's not in the leveling. It's not a leaky damper, nor an undamped segment of another string. It's not in the hammer at all, or rather in the angle of attack of the hammer (sorry Sarah, interesting post), since the strings exhibit at least similar behavior when plucked; at least the yowing ones still yow, and the clean ones are still clean. It seems to be in the string itself, and consists of beats. What I really want to know is what is beating against what, and while I really really really didn't want to speculate, the hypothesis that seems most convincing to me so far was posted by John Musselwhite: "Would those problematic single bass strings have LMFs [longitudinal mode frequencies] that are either unstable or out of tune with the rest of the string?" I have the CD from the Five Lectures, but I can't lay my hands on it right now. However, my memory is while the longitudinal modes produce different pitches, they are clear pitches, and not beating (?) Still, beating suggests non-harmonic stuff beating with harmonic stuff. ----- Well, I took a look at Conklin's patent on longitudinal mode design, and now I understand more than I wanted to. It looks as if the longitudinal mode can be tuned by controlling the weight per unit length of the wire, including core and loading, and falls roughly in the area four octaves+  above the fundamental pitch of the string. I still don't know for sure if this can beat with the partials produced by the normal flexural modes, but I don't see why not, and if so, I don't understand how you could reliably make bass strings ever, especially if they are so sensitive that the same string on the same model can come out either wonderful or hideous. One of you scientists out there set us straight. I'm getting interested in this, and I don't have time to be interested. Bob Davis</HTML>