>Hi Ron, > >I agree that all things have to be taken into account. But which way does >each item work? Towards or away from smear? Look at what the tensions in the sections will do with bridge rise/fall. It depends on the lengths of the sections and friction levels at the bearing points of each individual string. It isn't a question of moving toward or away from "smear". All the speaking pitches move, so it's how they move in relation to each other. >There are those occaisional >pianos when no matter what the humidity is the unisons and pitch level stay >wonderfully. And yes they have crown. >My hunch is that the plate is moving *more* than the soundboard...in the >area of c7 for example. Ok, I'll bite. Explain why the plate would move more than the soundboard, and why that would more reasonably account for this unison smear. >Another hunch is that the upwards movment of the >sound board (which is an actually arching) causes a vector of force to >twist the bridge counter clockwise. The bridge does tilt forward and backward as it rises and falls because it's curved, and the center will move farther than the low end, and much farther than the treble. It's not just in one direction, and I don't see how this could have any effect on your smear. >Lets try to consider each possible factor and with a *thought* experiment >decide whether it would cause pitch to rise or fall. Then if we add all >theses compenents perhaps some cause and effect could be seen for the >smearing of the unisions--other than the broad brush of humidity. Go for it. I've told you what I think, and why. Ron N
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