Soundboards

[Brian Trout]

Hey there Tricky Dicky! <Grin>

I never really thought about it, but I guess the process I think of as
tapering could be considered 'carving'.

Actually, you'll find more variation in the thickness dimensions than you
might think.  Some are thicker, and some are thinner.  Some have a lot of
'taper', and some have very little.

I think about the soundboard in very elementary terms, especially compared
to a number of other people.  Those strings in the treble, they don't move
very far when set into motion.  The soundboard doesn't need to move very far
either.  It needs to be quite rigid.  If it's not, it doesn't work so well.
Conversely, on the bass end of the piano, those bass strings are whipping up
and down pretty good, really covering some territory.  In the bass end, that
soundboard needs to be able to move.  If it's too rigid, it tends to have a
'clamping' effect upon the sound.  FWIW, I've been coming to the personal
conclusion that too heavy a downbearing in the bass end can have a
'clamping' effect as well.

So, to answer your question, the soundboard is typically thickest at the
belly rail, and gets thinner as it approaches the nose end.  Numbers that
are in common use are varied.  Belly rail thickness can be 3/8.  I've heard
of a little more, and I've heard of a little less.  I've seen thickness at
the nose at as little as 6/32, and then some that had little difference from
the bellyrail thickness.

I like to start around the inner curve of the bent side and taper down to
the nose and then back up along the straight side.  (This is on a grand.)  I
don't usually take it all the way to the belly rail, although I don't know
that it would necessarily cause any problems if I did.

This is one of those things that most every builder develops their own ideas
and techniques.  But it's interesting.

Hope I didn't take off on too wide a tangent.

Just had to add my $0.02

Brian Trout
Quarryville, PA
btrout@desupernet.net

----- Original Message -----
From: Richard Moody <remoody@midstatesd.net>
To: <pianotech@ptg.org>
Sent: Saturday, April 22, 2000 4:34 AM
Subject: Re: Soundboards


>
> ----- Original Message -----
> From: Tom Robinson <tomnjan@bellsouth.net>
> To: <pianotech@ptg.org>
> Sent: Thursday, April 20, 2000 4:13 PM
> Subject: RE: Soundboards
>
>
> > The arched top gives the guitar more volume and projection,
> > when compared to a "flat top".  So, is it possible that a piano
> > soundboard with a carved crown might sound better than an otherwise
> > equal piano with a molded or atmospheric crowned soundboard?  Has anyone
> > ever tried it?
> >
> > Tom Robinson
>
> At the turn of the century piano quality soundboards were 1/4 thick at one
> end and 3/8" at the other.  They were planed to get these specs. I don't
> know if you can call that "carved"  or not.  In addition they were arched
as
> in bent.  Now for a test question, where was the 3/8 inch, A: Treble  B:
> Bass  C: Middle D: Rim.
> If you need a "life line" to eliminate two, the remaining would be
A:Treble,
> B:Bass.
> Now who you gonna call?
> ---Tric
>
>