<!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 6.00.2800.1226" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY style="FONT-SIZE: 10pt; FONT-FAMILY: Arial; BACKGROUND-COLOR: = #ffffff" bgColor=#ffffff> <DIV><FONT face="Comic Sans MS" color=#000080 = size=3></FONT> </DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 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=Erwinspiano@aol.com href="mailto:Erwinspiano@aol.com">Erwinspiano@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> November 22, 2003 6:50 = PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Chaging upright bridge = location & affects</DIV> <DIV><BR></DIV> <DIV><FONT face="Times New Roman" color=#000040 size=3><STRONG> </STRONG></FONT><FONT face="Times New Roman" color=#000040 size=3><STRONG>    Since I need to do = extensive repairs anyway I'm considering building a solid bridge & attaching = it to the board where the apron is currently joined. The current string = lengths on note 1 is a very long 51& 1/2 "& note 28 is 41 & = 1/2". If I relocate the bridge It will be shortening those strings = by 2&1/2" on note 1. & 3 & 1/2" on note 28. The new = length will be  49'& 38 & 1/2" respectively. Still long = strings.  Because of the half moon shape the longer strings will become even = sorter especially if I use a straight bridge which, would be simpler. The = middle& longer strings would be shorten by as much as = 5."</STRONG></FONT></DIV> <DIV><STRONG><FONT face="Times New Roman" color=#000040 = size=3>   I'm looking for feedback from others who have done this or have an = idea about it. A prime consideration for me is, will this improve or inhibit = damping? How will it improve the sound? From what others have said = just attaching it to directly to the board will improve mechanical = efficiency. No argument there,</FONT></STRONG></DIV> <DIV><STRONG><FONT face="Times New Roman" color=#000040 = size=3>    In most uprights the dampers best location would be where the = hammers hit the strings but obviously they can't be there. </FONT></STRONG><STRONG><FONT face="Times New Roman" color=#000040 = size=3>Also I don't want to end up with the damper on some nodal point that = creates some harmonic that I can't resolve. In fact perhaps this is why the strings = on most uprights are so long perhaps to mitigate that effect. I don't know. = Will shortening the string push the optimal damping point even further up = the string towards the tuning pins? That to me would be bad.</FONT></STRONG></DIV></BLOCKQUOTE> <DIV dir=ltr> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 = size=3>Actually, this is rarely (if ever) a factor effecting the damping efficiency of vertical = pianos. This notion has been repeated so often we have generally come to believe = it even though it has no basis in fact. It becomes rather like the fundamental = political maxim: even the most blatant lie when repeated often enough will come to = be accepted by the majority as truth.</FONT></DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 = size=3></FONT> </DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 size=3>At = the risk of sounding like a broken record this subject has also appeared in one of = my Journal articles. Several years back I naively thought presenting a good = working introduction to the basic theoretical function of the piano damper in a = Journal I thought was at least widely read, if not studied, would do some = to dispel this obsolete and erroneous notion. I was wrong.</FONT></DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 = size=3></FONT> </DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 size=3>But = to get to the crux of your question: The first issue to consider is what you are doing = to the hammer strike point -- particularly across the bass/tenor break. Do you = have any idea? The second is to consider what you are doing to the impedance = relationship between the bridge and the soundboard system. How are you planning to = alter the design of the rib structure to accommodate this change? Finally, = knowing the speaking lengths of the first and last notes on the bridge provides = us with just enough information to be dangerous. T</FONT><FONT face="Comic = Sans MS" color=#000080 size=3>his information by itself doesn't tell us = anything at all that will help answer your question. How does this information relate to = the overall scale? How will the proposed changes relate to the overall = scale? Are you prepared to knowledgably make the scaling adjustments needed to = blend this new bass scale in with the rest of the piano?</FONT></DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 = size=3></FONT> </DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 = size=3>Obviously, I am in favor of modifying existing pianos to improve their performance. But to = achieve good (and predictable) results each change must be integrated with the = overall design of the piano. A lot more consideration must go into making = alterations like this than simply pondering what might happen to damping efficiency = (though evidence suggests that some manufacturers don't even get this far before = making even more extensive changes). Providing the background to help answer = this question is the whole point behind the all day seminars I give on the = subject. And even with six hours I barely have time to scratch the surface. = </FONT></DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 = size=3></FONT> </DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 size=3>Del</FONT></DIV></DIV></BODY></HTML>