summer sharpness in low tenor

[Farrell]

"...lowest plain wire strings will be really sharp, but the wound strings right next to them on the same bridge won't be anywhere near as sharp.  How does this happen?"

What the heck, I'll go out on a limb here - now this is just my guess: Plain wire strings in the low tenor are larger diameter than the cores of the low tenor wound strings. As the RH goes up and the panel and bridge rise - increasing the tension on the low tenor strings about the same amount - the thicker plain wire strings are more resistant to stretching to accommodate the increased tension, and hence go sharp. The thinner (core) adjacent wound strings stretch more and don't go as sharp. 

Again, just my guess.

Not sure about your second question. I suspect it has something to do with bridge end effects - maybe it's kinda like a loose wet noodle out at the end compared to the middle of the long bridge and reacts more. 'Course, that's not even a guess - not sure what to call it.....

Darn good questions though.

I know Ron Nossaman will have some pretty exacting thoughts on this....... Ron?

Terry Farrell
  ----- Original Message ----- 
  From: David Nereson 
  To: Pianotech List 
  Sent: Tuesday, July 15, 2008 3:09 AM
  Subject: summer sharpness in low tenor


      Most pianos go quite sharp in the summer because of higher humidity, and the sharpness is most pronounced in the low tenor.  But what I've seen quite often is that the lowest plain wire strings will be really sharp, but the wound strings right next to them on the same bridge won't be anywhere near as sharp.  How does this happen?
      Also, one would think that the middle of the soundboard would experience the most swelling, which would in turn affect the mid-treble most, not the low tenor strings down there in the corner of the soundboard.  What gives?
      --David Nereson, RPT
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