Soundboard Evaluation

[Baldwin Yamaha Piano Centre]

Hi Terry,
               Some food for thought for you.
   I have seen some pianos with good crown, some net bearing. (two 
measurements only) Yet sound awful in the treble. With 3 measurements it 
looks like bridge roll. Emmmmmmmmmm!!!!!
   Once stripped down I have found sever string grooves in the forward side 
of the bridge cap.

Resurface the cap, re notch the bridge pins, install new bridge pins. 
Correct plate height, and wow what a difference.

I have no doubt that you board is toast, but you must measure the angles of 
all planes to get a true picture.

Regards Roger




At 09:13 PM 6/1/02 -0500, you wrote:
> >Hmmmm. I agree three measurements will give you more info, but I should
> >think with the two you could conclude positive or negative bearing.
>
>Right, but not necessarily positive front bearing.
>
>
> >- when the piano was new, presumably both
> >the front and rear string segments were angled upward toward the bridge.)
>
>Hopefully, but again, not necessarily.
>
>
> >The instructions say to multiply these number buy 0.003 to get an answer in
> >thousandths. Mr. Lowell sure made a neat little gauge, but it does not seen
> >that he was a scientist. Thousandths of what? Inches? Degrees? It must be
> >degrees?
>
>That's 0.003" per inch, I believe, or 1/6° per line. That's why I like
>measurements stated in degrees, so it will mean the same thing to everyone
>everywhere - except maybe Elbonia.
>
>
>
> >I can see how this bridge is apparently rolled toward the piano rear in the
> >tenor, and overall bearing is negative in this area.
>
>Again, not necessarily. The back scale is considerably shorter than the
>speaking length, so the back angle changes much more for a given bridge
>height change than does the front angle. Assuming the bridge went straight
>down without any "roll" whatsoever, taking the speaking length and "duplex"
>length of say, F5 or C6, at what bridge top height above string plane would
>there be a positive back angle? What's the resulting front angle, and the
>difference in bridge heights between this computed one and what's there in
>the piano now? I seriously doubt that it's physically possible for a solid
>bridge to "roll" backward here.
>
>
> >However, it still seems to me that these numbers on a flat board mean this
> >board is toast. Opinions?
> >
> >Terry Farrell
>
>Agreed.
>
>Ron N

Roger