Buzz in an S&S D

[Ron Nossaman]

> With a 10% change in humidity and the upper cover off, the pitch were 
> the nasty resonance occurred drifted north a semi tone.  After 
> discussing it with the theater manager I learned that someone had been 
> brought by the dealership to repair the finish on the piano.  There was 
> steel wool all over the soundboard and we suspected FOs out of sight 
> under the plate.  I swung a flexible steel ruler around a bit but 
> couldn't scare anything out.  The ribs in the neighborhood looked tight 
> and there were no glue flakes apparent.
> We decided we could live with it until the piano could be cleaned out 
> and we can eliminate that possibility.  I did check strings and various 
> duplex segments all over to no avail.   Pressing on the soundboard at 
> one point does help alleviate it.
> 
> Andrew Anderson

 From killer Bs to Cs with an MC change? More evidence it's a 
resonance thing - a(n) harmonic boojum. Does pushing down on 
the soundboard in the specific place involve pulling up on the 
plate with fingers to lever down on the soundboard with the 
thumb? Does pushing down on the board alone make it go away, 
or pulling up on the plate at that spot without touching the 
soundboard? Nose bolt cap, bell bolt? How's soundboard 
clearance around both the nearest nose bolt and bell bolt? 
Does pushing up on the soundboard from underneath help like 
pushing down from above? How about pushing down on the plate? 
All clues.

Ron N