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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>“Drive the board” is perhaps not the best choice of words on my part. Strictly speaking, the only thing driving the board are the vibrating piano strings. The rest of it, as you describe below, are how best to establish a set of conditions that will clearly isolate the speaking length of the string, couple the string to the bridge, and do so in a manner that conserves the energy provided by string with the greatest possible efficiency; thereby resulting in long sustain and good volume. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Elsewhere, Ron Nossaman describes the lattice construction of the panel and ribbing on the Stuart, and I have seen pictures of same. While I have not heard a Stuart in person, I have heard recordings on a decent stereo system. My feeling about the Stuart sound has been what you describe below is that it sounds like a board with no bearing – very linear and lifeless, the sound just goes straight out, but has no arc or “push” to it. It has long sustain but, as we know, all sustains are not created equal in terms of their contribution to musicality. To my ear, it falls short of being an improved system over the best “traditional” boards by a fair amount.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>That said, could the Stuart or Phoenix agraffe be installed on a conventionally constructed board with compression, crown, and bearing skillfully blended together and sound very good in the ways we want a board to perform? I believe so. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Will<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] <b>On Behalf Of </b>David Love<br><b>Sent:</b> Wednesday, January 09, 2013 12:12 AM<br><b>To:</b> pianotech@ptg.org<br><b>Subject:</b> Re: [pianotech] Worst Bass/Tenor Crossover in Universe<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='color:#1F497D'>I don’t believe that bearing and crown are required to drive the board. The coupling of the strings to the bridge is enough to drive the board. The problem I have with zero bearing (if what you say about the Stuart pianos is true) is that it seems to miss an important function of downbearing which is to control impedance and to load some potential energy into the board by flexing it downward. The function of crown, then, is to create a domelike shape that can be flexed downward much like loading a spring. The unloaded spring has less potential energy and lower impedance characteristics. The key to this (simply stated) is to create a system that is crowned adequately and made light enough that the loading of the system with potential energy via the setting of downbearing also pushes the impedance up to the targeted level. The pairing of those two processes is critical. If the board is designed with the idea of no downbearing, then it can’t achieve the required impedance characteristics by loading. The board will have to be built heavier. Because there is no downbearing, the soundboard spring will be devoid of loading with potential energy and the tone will be relatively linear and lifeless. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>At least that’s how I look at it. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='color:#1F497D'>David Love<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><a href="http://www.davidlovepianos.com">www.davidlovepianos.com</a><o:p></o:p></span></p></div><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>I have heard that agraffe bridge systems like the Stuart is designed to be used at "zero bearing" ( I believe that Stuart claims to be such, if I am not mistaken). But I have never understood why, if all else about a soundboard assembly is equal in design and construction, that this would be the case. It seems to me like they would have more or less the same requirements of bearing and crown to drive the board. <o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Will Truitt<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p></div></body></html>