<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 6.00.2800.1126" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2></FONT> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <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">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> Monday, January 20, 2003 = 2:20 PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Yow-yow-yowing bass strings</DIV> <DIV><BR></DIV> <DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial size=2 = FAMILY="SANSSERIF">Friends,<BR><BR>Hep!   Hep!   = (Okay, I grew up in Texas)<BR></FONT></FONT></DIV><FONT = face=arial,helvetica><FONT lang=0 face=Arial size=2 = FAMILY="SANSSERIF"></FONT></FONT></BLOCKQUOTE> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial size=2 = FAMILY="SANSSERIF">I don't think I can hep you but I have comments = and questions.</FONT></FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>I'm not sure I know what the sound = is.  Would you classify it as a false beat? What rate is it? Is it the same = rate for all bad notes? Did you try tuning it 25 cents sharp and then 25 = cents flat to see any change?  A longitudinal vibration will not change = frequency with tuning.</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>There is a device I've long wanted to = build.  It would be a mike fed to a preamp and a tunable filter = connected to a tight fitting fluid filled head phone.  This would allow = you  to listen for and tune (with the filter) in the offending sound = to identify frequency and possibly identify the source.  There are = many uses for this and I now have even more reasons to build it.  Other = than that I don't have a clue.</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Carl Meyer  Assoc. PTG<BR>Santa = Clara, California<BR><A = href="mailto:cmpiano@attbi.com">cmpiano@attbi.com</A> </FONT></DIV> <DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial size=2 = FAMILY="SANSSERIF"> </DIV> <DIV><BR>I need an accurate scientific explanation for why SOME single = bass strings go yow-yow-yow, when played by themselves.<BR><BR>A new = customer I am about to go see, with a new Steinway B, said he wanted me to maybe = replace some bass strings that were "wobbling." I thought, okay, unisons or = voicing, but then he said they were singles. I realized I had accepted that = sound for decades, and just tuned around it, considering it a shortcoming of = shorter scales. Later that day, I listened to 5 B's, 4 L's, and a D, as well = as a 7'4" Boesendorfer.<BR><BR>All the Steinways had yowing singles, but not = necessarily on the same notes. Some notes would be clear. The D was the best of = the Steinways, reasonably clear, and the Bösendorfer was extremely clean.<BR><BR>The Steinways are single-wrapped and the Bös is = double-wrapped, but I also listened to some 126 cm Bostons, which are double-wrapped, = and they had random wows too.<BR><BR>I've always chalked it up to = "inharmonicity" or longitudinal waves or something like that, but I realized that doesn't = really work, and now it's driving me crazy not to be able accurately to = explain this. What is happening, and why is the Bösendorfer so = clean?<BR><BR>Wobbling in Stockton CA,<BR>Bob Davis<BR><BR><BR></DIV></BLOCKQUOTE></FONT></FONT></BODY></HTML>