Raise pitch 1 tone to exactly A/440. Not higher. What happens? It drops back down about 1/4 tone lower (roughly). IMO, there has to be some basic give throughout the entire structure of the piano although I have no scientific proof and could actually care less about looking for it, I have only common sense and mine is diminishing by the day it seems. Old age? Over worked? Under worked? Seems to me that the harp must have at least to some degree, a bit of flexibility seeing as the harp takes the basic brunt of the 18-20 tons of tension from the strings being attached to it. Although, it must still maintain the same basic structure or it would collapse completely upon a major pitch raise. The strings are doing the most giving and taking IMO by stretching and flexing. Possibly, moving them considerably across the bridges changes the tension across the sounding board enough to have some affect on it by the pulling of the wires, or the added tension. I would venture that little or no bearing, or little or no crown will not matter as far as pitch is concerned although, increasing tension over all in the piano may increase tone, the tone is increased mainly by placing tension back into the strings by stretching them out again if that is, if the tone changes and it doesn't always. Otherwise, the increase of tone must come from the added tension not only onto the wires themselves but, also from placing the total tonage back onto the whole structure of the piano again. After all, the piano is built to be at a certain tension not 2 keys below that or what happens? Eventually, tone is lost. I was taught that also, eventually, crown is lost as well after many years of neglect. Time for work. Have fun arguing about this now! :-))) Jer From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Al Guecia/AlliedPianoCraft Sent: Wednesday, August 05, 2009 7:40 AM To: pianotech at ptg.org Subject: Re: [pianotech] Soundboard deflection - Pitch raise Now look at what I got started. Considering it was a Wurlitzer spinet with probably no (or very little) crown to start and a (relatively) flimsy plate, I'm sure that would support plate contraction rather than soundboard deflection. I stand corrected. Al G From: David <mailto:davidlovepianos at comcast.net> Love Sent: Wednesday, August 05, 2009 1:38 AM To: pianotech at ptg.org Subject: Re: [pianotech] Soundboard deflection - Pitch raise I think one can safely remove soundboard deflection as one of the variables for reasons already stated. That leaves rim (bracing included) and plate. Since the two are interlinked then the contraction of one must also mean the contraction of the other. But since the tension is born by the plate which is supported by the rim it should be safe to assume that the initial contraction takes place in the plate. If one wants to, I'm sure it can be measured, though I haven't done it. Personally, I'm satisfied with the conclusion but I fully support those who wish to take it to the next level and provide the raw data. David Love www.davidlovepianos.com From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of PAULREVENKOJONES at aol.com Sent: Tuesday, August 04, 2009 9:24 PM To: pianotech at ptg.org Subject: Re: [pianotech] Soundboard deflection - Pitch raise No so much a suggestion of ambiguity, for there is none, just a wish for a clearer idea of the depth of the conclusions which can be drawn without accounting for all variables. Grasshopper? :-) P _____ avast! Antivirus <http://www.avast.com> : Outbound message clean. Virus Database (VPS): 090804-1, 08/04/2009 Tested on: 8/5/2009 8:39:24 AM avast! - copyright (c) 1988-2009 ALWIL Software. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090805/5540dfb3/attachment.htm>
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