See my other post but of course diameter plays a role. It is a factor in determining break point percentage. A thicker string will have a higher break point percentage and a thicker string will need to be at a higher tension to achieve a certain frequency at a given length than will a thinner string. Simple stuff. The claim about BPP as a factor in determining which string will go out of tune more goes way back. You don't need to use BPP in the formula, you can simply calculate it for the two strings in question and observe the relationship-see my other (corrected post). Please don't be so antagonistic. I'm really trying to help you here. David Love davidlovepianos at comcast.net www.davidlovepianos.com -----Original Message----- From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Richard Brekne Sent: Monday, June 11, 2007 2:57 AM To: caut at 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." -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/20070611/17e8a8c4/attachment-0001.html
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