Soundboards

[Mark Story]

Hi Dan,

----------
From:       Dan Squire[SMTP:djs08201@Jetson.UH.EDU]
Sent:       Friday, August 04, 1995 10:17 AM
To:   Multiple recipients of list
Subject:    Soundboards

      A  friend of mine has an old concert grand.  The piano is in excellent
condition, the bearing is good, the crown is good,  the whole piano is go=
od.
There was only one little problem, this piano has very little volume in t=
he
midrange and even less in the treble.  When I looked at the underside of =
the
soundboard I noticed that the soundboard ribs had no taper at the ends.  =
I
tried to woo the piano into submission by chanting equations at the
soundboard.  I then brought my computer in and showed it the simulations =
I
generated of a vibrating membrane,  the piano still had the same problems=
..
I looked over at my friend and for some reason the poor man was in tears,=
 I
couldn't imagine why.  I was defeated.
      Has anybody had problems with untapered ribs?  Has anybody tried to tape=
r
the ribs while the board was still in the piano?  If so, did it help?  Wa=
s
it more trouble than it was worth?  Has anybody ever replaced one of thes=
e
boards?  If so, did you taper the ribs?  What affect did it have?  Did it=

make enough of a difference to validate the effort?

Dan Squire
University of Houston

As far as the laws of mathematics refer to reality they are not certain, =
and
as far as they are certain, they do not refer to reality.
                                          - Albert Einstein


I'm way behind in reading my mail, and I'm surprised no one has responded=
 by this time.  Anyway, on the assumption that you are talking about a so=
undboard with ribs that are "unpared" (in bellywork parlance), I can't ho=
nestly imagine how this board would work.  The rib paring is integral to =
the overall scaling of the soundboard, but in general it would be hard fo=
r me to conceive of a successful design that didn't have pared ribs.  If =
you can manage to do it with the board in, I think it would be worth a tr=
y. You might try laying the piano on it's side to give you a better posit=
ion. If you replace the board, you most certainly should rescale the boar=
d with pared ribs.  If you are rebuilding a piano and have the opportunit=
y to correct an obviously failed design, it would be a wasted opportunity=
 not to do so.  Steinway advocates installing diaphragm scaled boards in =
older, pre diaphragm grands (I don't always do this).  I have changed the=
 rib scaling in odd-ball designs that obviously didn't work.  I don't pre=
tend to have the engineering expertise to design the absolute optimum sou=
nboard/rib scale for any particular piano, but I can (and will) apply com=
monly accepted principles of good design to correct glaring faults like t=
he one you describe.  BTW, what kind of beast is this?

Mark Story, RPT

mstory@ewu.edu
Eastern Washington University Music Department
Cheney, Washington, USA=09