New Old Bluthner Soundboard

[RicB]

Hi one and all. Just a couple clarifications to Terrys announcement.  
The instrument is indeed first year production Bluthner Patent Grand. 
The university and I share ownership of this instrument.  The soundboard 
we built was designed not to just keep the origional visuals intact, but 
to strengthen the existing design. It is my thinkng that Bluthner used 
grain direction purposely perpendicular to the bridge because it is 
strongest that way. This would provide a some measure of any needed 
support against whatever downbearing there was.  Ribs alligned cross 
grain then in such an arrangement will yeild minimal support (relative 
to modern design) especially in the treble. However the ribs do provide 
a secondary mission of importance in dealing with anisotropic property 
of the panel with all that implies for sound transmission across grain.

The laminated crown and the way we did it, is meant to strengthen the 
treble area and basically leave the bass alone.  As Terry said.. 3 plys 
were used. The outside two go in the same direction as the origional 
panel, while the inside one is offset roughly 20 degrees and because of 
its taper ends about 2/3s of the way from the belly.  Essentially the 
bass area and lower tenor is unchanged from the origional while the rest 
of the board has increased stiffness and crown.

This is going to allow me to introduce just a bit more tension on the 
instrument by lengthening the treble part of the scale very slightly, 
and allow for some measure of downbearing.   The highest treble DOES 
have an effective support... its just not so easy to see.  The <<rim >> 
here is morticed into the case.

I'm real anxious to get the thing up and running and to see if my 
reasoning will result in a nice musical sound.  I'm looking for a bit 
more clarity and sustain in the treble area while leaving the bass sound 
alone. 

The origional panel will be restored and framed for viewing purposes and 
to provide a historical record of the origional panel and scale.  
Nothing else about the instrument will be changed.

Any and all comments on the whole thing are more then welcome.. either 
on the list or privatly.

One other thing.... Terry has been fantastic the whole way. In no small 
part the end result is a joint effort. We had long exchanges about what 
the <<cutoff>> bar really was, how to handle rib tapering if we were to 
change anything about this... how much crown to attempt to put into the 
laminated assembly... etc etc.  And his workmanship is exemplary.   I 
cant thank him enough !

Cheers
RicB


    Thought some of you folks might get a kick out of a picture of my
    latest project - building a complete (ribbed) soundboard for a very
    old (1850s or 60s?) Bluthner grand. Richard Brekne, over in Norway,
    is rebuilding the piano and asked me to build the soundboard for
    him. I believe he inidicated that the piano is from the first year
    of Bluthner's production.

    I believe the piano is owned by a University, and there was quite a
    bit of interest in maintaining the original design of the belly. The
    piano was reportedly lacking in the upper treble and there was a
    wish to do something to try and make the treble a bit more prominent
    for more even tone, yet keep the appearence original. Our solution
    was to build a 3-ply laminated panel with a tapered inner ply.
    During glue-up we pressed the panel into a caul (of sorts) -
    especially in the high treble - to build some crown into the panel
    itself. As you can see in the picture, there is no effective kind of
    support for the panel in the upper treble.

    As far as the structural aspects of building the soundboard go, we
    seem to have reached all our goals successfully. I'm about to ship
    the soundboard across the big pond and time will tell how musically
    successful our efforts have been after Richard finishes the project.

    Our soundboard is pictured below. I've got tons more pictures and
    info if any of you are interested - email me.

    Terry Farrel