Now here is an interesting thought

[Don Mannino]

ric,

I'll chime in briefly on this one because I have 
thought about this in a similar way - not with 
the front bridges you mention, but with the pinblock itself.

There is a school of thought that open pinblocks, 
and even un-bushed plate webbing (no pin 
bushings) has a tonal benefit.  I have heard of 
tone tests where a concert grand was first strung 
up, tuned, voiced, performed on and recorded with 
tuning pin bushings, then the pins were pulled, 
the bushings removed, and pins driven back in 
with the same strings.  The piano was then tuned 
and stabilized, all of the string seating and 
voicing work was done, and the same pianist then 
performed the same music on the piano in the same recital hall.

I have not heard the recordings, but I was told 
that a blind test using just the recordings was 
done with 20 piano knowledgeable people (about 
half of whom were technicians).  Apparently the 
differences were not huge, but were audible 
enough that people could identify the differences 
in the recordings.  According to someone who 
heard the two recitals, the sound was very 
obvious sitting in the hall - but of course that 
kind of evaluation is very subject to predispositions.

The piano in question was one with a fully fitted 
pinblock, mortised into the case and stretcher.

I don't have enough evidence to be convinced 
myself, but I respect the opinions of the person 
who told me about this, so I am open to this 
possibility.  I am quite sure as well that the 
bridges you mention would contribute as well - 
perhaps not through coupling to the soundboard 
necessarily, but just the resulting vibrations of 
the pin panel and the stretcher would influence the overall tone.

I feel that there is also a negative impact on 
the tone of having such a soft termination as a 
wood bridge at both ends of the strings, as with 
your Blüthner.  At least, it would be negative to 
me, but then perhaps a more muted tone quality 
with shorter sustain in the high partials (which 
can seem to enhance the fundamental) was the intention of the designer.

Don Mannino

At 02:35 AM 12/13/2006, you wrote:
>Hi folks
>
>I have gotten a bit deeper into this old 
>Bluthner of mine and  noticed something I thought might be worth a few lines.
>
>The tenor and bass registers of this old grand 
>have their front terminations in a bridge 
>complete with front  and back bridge pins 
>embedded into the pin block. The metal cover for 
>the pinblock is cutout to accomodate these two 
>bridges.  The pinblock then in turn is coupled 
>directly to the belly rail allowing a direct 
>route from these two bridges back into the soundboard.
>
>Now I am aware that whatever vibrations going 
>through this way are going to be limited... but 
>it struck me that they could be significant 
>enough to yeild a positive contribution to the 
>overall amount of string energy that ultimately 
>gets transfered to the sound board.  And I was 
>interested in what ever thoughts any of you might have on the matter.
>
>Cheers
>RicB