<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 10 (filtered)"> <style>  </style> </head> <body bgcolor=white lang=EN-US link=blue vlink=purple> <div class=Section1>     In Robert’s book “The Calculating Technician” the formulas are given and you can program your own spread sheet.  The original claim was that when comparing the degree to which two strings will go out of tune with a change in length, the break point percentage was an indicator of which string would go out of tune more.  The other statements below came about as a discussion of the math.  If you do as I said and compare two strings which start out with different BPP and calculate the change in tension for a given change in tension and then see how that translates to a change in frequency, you will see that the one with higher BPP string will have a greater change.  You have to reprogram your spreadsheet to make that calculation for you since it is not generally set up to have Frequency as a dependent variable.           Note               Length             Diam                                                                 BPP                  Tension                  Frequency   <table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0 width=759 style='width:569.0pt;margin-left:-.9pt;border-collapse:collapse'> <tr height=17 style='height:12.95pt'> <td width=67 nowrap height=17 valign=bottom style='width:.7in;border:none; border-left:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:12.95pt'> A - 7 </td> <td width=41 nowrap height=17 valign=bottom style='width:30.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=50 nowrap height=17 valign=bottom style='width:37.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'> 70.0 </td> <td width=40 nowrap height=17 valign=bottom style='width:29.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=44 nowrap height=17 valign=bottom style='width:32.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'> .032 </td> <td width=38 nowrap height=17 valign=bottom style='width:.4in;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=44 nowrap height=17 valign=bottom style='width:32.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=34 nowrap height=17 valign=bottom style='width:25.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=38 nowrap height=17 valign=bottom style='width:.4in;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=40 nowrap height=17 valign=bottom style='width:29.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=52 nowrap height=17 valign=bottom style='width:38.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=44 nowrap height=17 valign=bottom style='width:32.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'> 76% </td> <td width=48 nowrap height=17 valign=bottom style='width:35.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=64 nowrap height=17 valign=bottom style='width:47.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'> 138.64 </td> <td width=56 nowrap height=17 valign=bottom style='width:41.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=59 nowrap height=17 valign=bottom style='width:44.4pt;border:none; border-right:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:12.95pt'> 3322.44 </td> </tr> <tr height=17 style='height:12.95pt'> <td width=67 nowrap height=17 valign=bottom style='width:.7in;border:none; border-left:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:12.95pt'> A - 7 </td> <td width=41 nowrap height=17 valign=bottom style='width:30.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=50 nowrap height=17 valign=bottom style='width:37.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'> 60.0 </td> <td width=40 nowrap height=17 valign=bottom style='width:29.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=44 nowrap height=17 valign=bottom style='width:32.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'> .032 </td> <td width=38 nowrap height=17 valign=bottom style='width:.4in;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=44 nowrap height=17 valign=bottom style='width:32.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=34 nowrap height=17 valign=bottom style='width:25.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=38 nowrap height=17 valign=bottom style='width:.4in;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=40 nowrap height=17 valign=bottom style='width:29.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=52 nowrap height=17 valign=bottom style='width:38.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=44 nowrap height=17 valign=bottom style='width:32.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'> 56% </td> <td width=48 nowrap height=17 valign=bottom style='width:35.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=64 nowrap height=17 valign=bottom style='width:47.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'> 256.85 </td> <td width=56 nowrap height=17 valign=bottom style='width:41.8pt;padding:0in 5.4pt 0in 5.4pt; height:12.95pt'>   </td> <td width=59 nowrap height=17 valign=bottom style='width:44.4pt;border:none; border-right:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:12.95pt'> 3322.44 </td> </tr> </table>   <div> David Love davidlovepianos@comcast.net www.davidlovepianos.com </div> -----Original Message----- From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] On Behalf Of Richard Brekne Sent: Monday, June 11, 2007 2:57 AM To: caut@ptg.org Subject: [CAUT] pre-stretching new string?   David Below are your two posts on the matter.  The lower post clearly states your original claim... which I fail to see you have supported.  In fact... half of it is directly wrong as the example I gave showed. Diameter doesnt play into it at all... tho it seems pretty clear you claim it does.  As for the rest...see subsequent posts. The upper quote suddenly jumps into a new claim about breaking point percentages which is off in an entirely different tangent.  Breaking precentage is not part of any tension formula... it is a procedure of its own. So this fits into a claim that you can (and I quote)      "You can certainly rewrite the formula to isolate pitch, or tension, or length, or diameter."  er... how ? Perhaps you have a way of calculating change in pitch from change in length with some breaking % formula now ?  Please... if you have some formula the rest of us do not... share it with us.  I spent a couple months exchanging posts with Mark Davidson, Sarah, Alexander Galembo, Jim Ellis, Rhodes, Askenfelt and a couple others and each and every one of them reviewed Galembos paper to me and agreed this was the basic approach and a quite adequate one as well of calculating change of pitch for change in length.  Cheers RicB Grin "You will find in the example you listed below that since both speaking lengths are equal, they will both yield equal break point percentages. While you have to increase the tension in the string with the greater diameter, it also has a higher break point so the break point percentage does not change.  Set up your example using two notes different speaking lengths to begin with so that the BPPs are not equal.  Then run your calculations for an equal change in length. "   "Sorry, but it's not quite a complete enough formula for purposes of this discussion.  When comparing two strings that produce the same pitch but with different tensions, either the original length will be different or the diameter will be different (or both), thus a similar change in length will yield a different change in tension and thus pitch."     </div> </body> </html>