<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD><TITLE>Re: Bridge design</TITLE> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <STYLE type=text/css>BLOCKQUOTE { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } DL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } UL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } OL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } LI { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } </STYLE> <META content="MSHTML 5.50.4134.600" name=GENERATOR></HEAD> <BODY bgColor=#ffffff> <DIV><FONT color=#000080></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=ron@overspianos.com.au = href="mailto:ron@overspianos.com.au">Ron Overs</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> July 06, 2002 6:31 = PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Bridge = design</DIV> <DIV><BR></DIV> <DIV> <DIV><FONT face=Verdana color=#000000></FONT></DIV><FONT = face=Verdana color=#000000><I>Del wrote;</I></FONT></DIV> <DIV><FONT face=Verdana color=#000000><I><BR></I></FONT></DIV> <DIV><FONT color=#000080></FONT><FONT = color=#000080></FONT><BR></DIV> <BLOCKQUOTE cite type="cite"><FONT face=Verdana = color=#000080><I> -- even better, design in a transition bridge -- and/or redesign the = ribbing, and leave out the gaps.</I></FONT></BLOCKQUOTE> <DIV><FONT color=#000080></FONT><FONT = color=#000080></FONT><BR></DIV> <DIV>Agreed. Of course, the transition bridge is a really sensible = work around for a piano which has bass/treble break which is lower than desirable, = for the particular length of piano.</DIV> <DIV><FONT color=#000080></FONT> </DIV> <DIV>Interestingly, something I have noticed about transition bridges = is that they also need an extension running out from their treble end, to = increase the impedance. This extension would therefore run further out towards the = center of the board. </DIV></BLOCKQUOTE> <DIV dir=ltr><FONT color=#000080>A transition bridge will exhibit = the same end-of-bridge impedance problems as a continuous long bridge. = The cleanest solution is to attach the upper end of the transition bridge to the = long bridge and extend the lower end just as would be done with a continuous = bridge. </FONT></DIV> <DIV dir=ltr> </DIV> <DIV dir=ltr><FONT color=#000080></FONT> </DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"> <DIV>I am thinking now that it should be long enough to run over = another sound board rib. Of course, none of this stuff would be necessary if the = cross was in the appropriate place to start with. After a hundred years we are = still stuck with a multitude of small and mid sized grands with the cross = scaled too far down, just to make them look like their bigger = brethren.</DIV></BLOCKQUOTE> <DIV dir=ltr><FONT color=#000080>I'm not sure what the rational was = behind placing the bass/tenor transition where it is on the so-called 'modern' = piano. Especially, but not limited to, the 'modern' small piano. But it's there = and has to be coped with. The transition bridge is probably the best way to do = this, but even simple rescaling using bi-chords on up a bit is better than = nothing. A lot better! The biggest problem with it is the inability to blend = inharmonicity, but this is more of a tuning problem than a voice problem.</FONT></DIV> <DIV dir=ltr><FONT color=#000080></FONT> </DIV> <DIV dir=ltr><FONT color=#000080>In either case, the end of that = bridge -- regardless of type -- best have an extension of some kind.</FONT></DIV> <DIV dir=ltr><FONT color=#000080></FONT> </DIV> <DIV dir=ltr><FONT color=#000080>Del</FONT></DIV></BODY></HTML>