soundboards improving with age? or what else?

[Delwin D Fandrich]

----- Original Message -----
From: "Richard Brekne" <rbrekne@broadpark.no>
To: <pianotech@ptg.org>
Sent: June 08, 2001 12:25 AM
Subject: Re: soundboards improving with age? or what else?


>
>
> Delwin D Fandrich wrote:
>
> >
> > > Every tree is different. Every board is different. I think that in
piano's, by the
> > > time the board has reached it's ideal age, it many times has already
lost it's
> > > crown.
> >
> > Age has nothing to do with the performance of a piano soundboard. At
least
> > not age by itself. It's time under stress that we are concerned with.
That
> > and how much stress the soundboard is subjected to during that time. In
> > other words, there is no 'ideal age' for a piano soundboard. It still
boils
> > down to how much does it weigh (what is its mass) and how stiff is it?
And
> > the stiffness of a piano soundboard changes with time under load.
> >
> > Regards,
> >
> > Del
>
> Ok... cant let this slip by as I fail to see that this has been shown to
be true
> beyond any reasonable doubt... for that matter a long ways from it.

Well, there is a certainly a growing body of evidence running from Wolfenden
and running through all of the late 20th century piano researchers that is
leaning that way. Do your homework. Read, (no, study!) the basic work that
has been done on the subject. Fundamentals of Musical Acoustics (Benade),
The Acoustics of the Piano (the Five Lectures series), The Physics of
Musical Instruments (Fletcher/Rossing) come to mind. Study a few books on
wood technology.

Then design and build a few pianos using your own ideas and theories. Or at
least rebuild a few using your own ideas and changes. Listen to and analyze
the results. Actually learn something about the principles of piano
soundboard operation. Then see if you still think these ideas of aging wood
have any merit. If they do then you might also have discovered the reasons
why they have merit.

The piano soundboard is a two-dimensional, wave-carrying medium. Within
limits it doesn't matter all that much what it is made of. Spruce is the
most popular right now. That doesn't mean it will stay that way. Laminates
have been successfully used. (I know, they've been unsuccessfully used as
well.) Though I didn't build it, I was able to study a piano using a
soundboard made of a foam core with aluminum faces. It sounded surprisingly
good, though not great. Hadn't aged enough to reach its peak, I guess.

Just what are the physical characteristics of wood that are supposed to be
undergoing these remarkable changes just with age? Is age making the wood
stiffer? No, aging wood doesn't do that. Is age making the wood more
flexible? No, aging wood doesn't do that either. Is age supposed to be
making the wood more massive? Less massive? Age doesn't do that either.
Except through the addition of subtraction of moisture as it takes on or
gives up moisture with climatic changes. Nor does the age of wood affect its
internal friction or the speed of sound either with or across grain. So,
what is left? Perhaps this is the mystery that Steinway has captured in its
infamous 'Mystique Oil.' Instant aging. There is no evidence--empirical or
scientific--that wood, left in an unstressed condition, goes through any
changes that would affect its performance in a piano soundboard.



> Just because
> we know that the most significant measureable factor on soundboards is
stress
> over time does not serve as proof that there are not other factors
involved.

No, it doesn't. But if you can't measure them, or document any changes
directly related to them, or even hear them, are they factors that really
matter?

Now, I'm going to turn this around. The best wood technology as applied to
the piano soundboard discounts 'age' as being a contributing factor in any
time related change of piano tone characteristics. That is age alone, apart
from time under stress, which is the major factor. Still, some few continue
to believe that it is. Apparently including yourself. So, can you identify
and quantify any real and measurable characteristics of wood that do change
over time and that might have some real and measurable effect on the tone
performance of a piano? What are these other factors that are involved?



> You just posted that a 100 or so year old  panel with new ribs "probably"
would
> sound the same as a brand new panel in relation to Andre's posting. A
direct
> consequence of this reasoning (and the above) is that we dont need new
panels at
> all. Just rip out any old panel from an old birdcage wreck...glue it back
into
> one piece and rib crown it with new ribs and it will sound good as new. I
am
> sure the soundboard manufacturers will be very pleased at this notion.

Yes, I did, didn't I? And, yes, all other things being equal, this is pretty
much the case. After all, just what has changed during the life of that old
soundboard, be it from an old birdcage wreck or an old Steinway grand?

Longitudinally, (that is, with the grain) not much. There has been some
nominal compression longitudinally, but not enough to worry about.
Across-grain, though, we have a problem. There has been a lot fiber
compression due to compression set and the old wood is now much weaker
across-grain than it was when it started out. It is also considerably less
resilient so we can't just dry it out and compression-crown the whole thing
all over again. We'll have to do something about that. The thickness hasn't
changed much unless somebody got carried away with their sanding. The mass
hasn't changed much.

So, once the original ribs have been removed what we have is a panel that is
about the same longitudinally, but somewhat weaker and less resilient
across-grain. Indeed, the panel might well have cracked and broken into two
or more pieces. We'll solve these little problems by gluing the pieces back
together and putting on a nice new set of crowned ribs. In this way we
establish a new crown based on the curve cut into our new ribs, we establish
some amount of cross-grain stiffness (dependent on the length, height and
width of the new ribs) and remove the necessity to compress the panel
across-grain to form crown. What we end up with is a rib-crowned soundboard
assembly that just happens to use the original soundboard panel in place of
one made using new wood. Makes good use of Earth's resources and the
acoustics of either will be about the same.

And I don't particularly care whether the soundboard manufacturers are
pleased with this notion or not.



> You show us, refere us to, quote, or in some other sense document the
studies
> that conclusively show that there are no significant changes in the way
sound
> and wood inter-relate as a result of wood ageing, or varnishing for that
matter.
> When you do, you will no doubt end the discussion that has been raging
about
> this for god knows how many years. Until you can do this...you reside in
exactly
> the same place as those who declare other unsubstantiated ideas to be
fact. No
> offence meant Del... but really... You want to put an end to all the
"mystikk"
> surrounding this and other such subject matter... then you need to stop
blowing
> your own magic smoke first.

No, Richard. You show us, you refer us to, you quote, you--in any other
sense--document any study, anywhere, from any source, that scientifically
demonstrats that there ARE significant changes in the way sound and wood
inter-relate as a result of wood aging, or varnishing for that matter. When
you can do this you will lend some credibility to the claims that this
relationship exists. Until you, or others making these claims, can do this
you will reside in exactly the same place as those who declare other
unsubstantiated ideas to be fact.

No offence, Richard, but really, if you want to add any credibility to these
claims you need to come with some kind of proof--or at least some credible
theory to explain them--or find some evidence to substantiate them or you
need to stop blowing your magic smoke.



> And for the last time... nobody is comparing Violins directly to pianos...
the
> Violin examples are used in conjunction with wood ageing... not with
differing
> stress situations. Until you prove that ageing of wood per se has no
> significance... then it will continue to be natural to use such examples.

Sure seemed like it to me. Until you can prove that the aging of wood per se
has any significance in the performance of the piano soundboard I will
continue to reject such comparisons.



> Science is science... treat it that way.

As you say, science is science. Treat it that way.

Regards,

Del