[pianotech] How come?

[Bppiano]

Thanks for the input, I imagine that a soundboard doesn't adjust evenly under the bridge, accounting for different pressure from the breaks provided by the plate, and so on.  We all know that good string stability is not expected as much around the breaks between the plate struts for example.  I wonder if anyone has examined an old soundboard to see evidence of more or less stress fatigue at these points.  Or the inherent dead spots of a soundboard.  Sounds like a project for someone with a lot more of a scientific vocabulary than myself.

Bruce P






-----Original Message-----
From: Ron Nossaman <rnossaman at cox.net>
To: pianotech <pianotech at ptg.org>
Sent: Sat, Oct 23, 2010 9:43 pm
Subject: Re: [pianotech] How come?


On 10/23/2010 8:08 PM, Bppiano wrote:
 I'd be interested to hear what Mr Nossman says about this.
Is that a cage I rear rattling? That's Ron too, incidentally.

Could the
 soundboard be settling a little every year? Those notes are obviously
 near the edge of the board near the inner rim, could the give (losing
 crown) in a soundboard occur first near the rim?
If you can measure any crown at all up there under the best of 
ircumstances, I'll be really impressed. So no, I can't see it as the 
oundboard settling. Any change in absolute overall string length, 
owever accomplished, will have a greater effect in the shortest overall 
trings, and in the low break% strings. That could account for the last 
ctave effect if the rest of the system was available for comparison. 
nfortunately, it isn't in enough detail. I don't see it as hammer 
echnique, stretching strings, mysterious atmospheric conditions, or 
vil spirits either. Then most of the rest of the piano stays solid, 
ou're doing something right. Wood compaction is on the short list of 
ikely, but I don't have details that hold up to microscopic analysis, 
o I can't really say.
Bottom line is, I don't have enough information to make an intelligent 
ssessment, so until I do, I don't know and can't guess.
Ron N

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