[CAUT] Humidity, Bridge caps, pitch drift

[Ron Nossaman]

Ed Sutton wrote:
> I wish that someone would make a direct measurement of the supposed rise 
> of the soundboard, and of the supposed bridge roll.
> I also wish there was a way to stabilize the soundboard so we could find 
> out if humidity causes a swelling of the bridge cap sufficient to 
> explain the pitch change. Or perhaps build a piano with a plexglas 
> soundboard and wooden bridge, and another with a wood soundboard and a 
> solid plastic bridge.
>  
> For example, I am dealing with a piano with a full, enclosed climate 
> control system underneath, and it continues to have fast responses to 
> ambient humidity changes.  I'm wishing I could install tiny heater bars 
> all along the bridges to see what happens.
>  
> And I realize that anything we prove about one piano may have no 
> relation to another piano.
>  
> Ed S.

Ed,
I've tried, for myself, to quantify some of this stuff through 
experimental measurement and the dreaded math, but the echo 
always bounces back from the collective human void as a total 
mystery. You're no different from any of the rest of us. Spend 
your own nickel, burn your own time and brain cells, take your 
own hit on income you might have otherwise made, hang your own 
- stand in the wind and field the arguments, disbelief, and 
general lack of awareness constituting the echoes resulting 
from presenting your findings to your fellow techs. Then you 
can either average the responses to determine what is the most 
generally believed "truth", or you can follow the science and 
try to condense something rational from the evidence in spite 
of conventional wisdom and the roar of the grease paint.

Or you can just shut up and follow the money.

Your call.
Ron N