<HTML><HEAD> <META content="MSHTML 6.00.2715.400" name=GENERATOR></HEAD> <BODY> <DIV><FONT face="MS Sans Serif" size=2>Since it occurs irregularly, it would make sense to look at the string manufacturing process.  My inclination (and I know you didn't want speculation) is that it has something to do with how the wrapped portion of the string is tensioned onto the core wire.  Too much tension, for example, might cause the core wire to twist, or somehow become torqued in a way that creates irregular or mismatched patterns when the string is set to vibrating.  Since this problem seems to occur mostly in the heavier wrapped strings, it may be because the thicker diameter of the wrappings in these strings requires more tension in the horizontal direction while the string is being wrapped.  The need for greater tension may tend to create more variation in tension, simply put, it might be harder to hold it steady.  It might be interesting to compare two strings, one that yows and one that doesn't, off the piano by allowing them to hang freely and see if the yowing one differs in terms of the amount of natural twist.  </FONT></DIV> <DIV><FONT face="MS Sans Serif" size=2></FONT> </DIV> <DIV><FONT face="MS Sans Serif" size=2>Just a thought.</FONT></DIV> <DIV> </DIV> <DIV><FONT face="MS Sans Serif" size=2> <DIV>David Love</DIV> <DIV><A href="mailto:davidlovepianos@earthlink.net">davidlovepianos@earthlink.net</A></DIV> <DIV> </DIV></FONT></DIV> <DIV> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid"> <DIV style="FONT: 10pt Arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B> <A title=BobDavis88@aol.com href="mailto:BobDavis88@aol.com"></A></DIV> <DIV style="FONT: 10pt arial"><B>To: </B><A title=pianotech@ptg.org href="mailto:pianotech@ptg.org">pianotech@ptg.org</A></DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> 1/23/2003 6:58:17 PM </DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Yow-yow-yowing bass strings</DIV> <DIV><BR></DIV><FONT size=2><FONT face=arial,helvetica><FONT lang=0 face=Arial size=2 FAMILY="SANSSERIF">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.<BR><BR>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:<BR><BR>"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?"<BR><BR>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. <BR>-----<BR>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.<BR><BR>One of you scientists out there set us straight. I'm getting interested in this, and I don't have time to be interested.<BR><BR>Bob Davis</FONT> </FONT></FONT></BLOCKQUOTE></BODY></HTML>