Oops... Re: Unusual rib structure?

[Delwin D Fandrich]

----- Original Message -----
From: "Sarah Fox" <sarah@gendernet.org>
To: "Pianotech" <pianotech@ptg.org>
Sent: May 07, 2003 2:02 PM
Subject: Re: Oops... Re: Unusual rib structure?


> Hi Del et al.,
>
> So these rib ties were somewhat of a "missing link" between the old
> no-cutoff-bar design and the more modern cutoff bar construction???  Just
> curious -- What was the evolutionary history, in a few sentences or less?
>
> Thanks!
>
> Peace,
> Sarah

(Sarah, you should by now know better than to ask me to whip something like
this off in "a few sentences or less....")

Your Wissner, like almost every other U.S. built, and now Asian built,
concert grand traces it design origins back to the Steinway Model D. The
Model D, in turn, traces its origins back to a synthesis of various pianos
that formed the transition between the harpsichord/fortepiano and the
so-called "modern" piano. Steinway actually introduced very little that was
truly new and original. One of the things he brought forward was the large,
open soundboard. (Yes, I know that many pianoforte's did utilize some form
of soundboard cutoff. Most of those I've seen, however, were basically
floating cutoff's however. Much like the straps used by Steinway, et al.)

By the 1880s piano makers were just beginning to investigate the
performance of various rib structures and soundboard shapes and
configurations. And by this time the Steinway pianos had already became
exceptionally powerful marketing and manufacturing successes. Market forces
then, as now, dictated that there were more followers than leaders in the
madness that made up the late 1800s and early 1900s piano business. Even
though many builders were building better, and better sounding, pianos than
anything coming out of the Steinway factory, they tended to get lost in the
marketing and promotional wars that could, and did, become quite brutal.

Many piano makers seem to have had a reasonably good grasp of the basic
design principles that go into making a good, efficient soundboard
system--we still occasionally see their products in our shops yet today.
Well though out and often highly innovative work. But they didn't survive
the marketing wars any better then than they do today.

Ironically, even though Steinway marketing today carries on about the large
soundboard/large amplifier foolishness, at one time somebody in the company
clearly understood the value of a good soundboard cutoff bar--witness the
shape of the soundboards in some of their early vertical piano designs. But
this never carried over to their grands. At least not in the later
production designs that have now become locked in tradition--some of their
earlier vertical piano designs did have relatively substantial cutoffs.

Pianos with purely compression-crowned soundboards tend to lose their crown
and, hence, their ability to carry sustain, through the upper tenor and
lower treble sections relatively quickly. (Relative, that is, in terms of
piano life.) Both the addition of the so-called "resonator" strap (which
stiffens up the soundboard assembly in an area which really should be
infinitely stiff) and the upper bellyrail-to-rim strap are indications that
somewhere back there someone in their design department understood at least
the basics of why this was happening. These two devices both help, but do
not solve, the real problem.

Back in the late 1980s I was working on a small soundboard design and was
able to look at the design I had come up with using a rather primitive
modal analysis model. It was fascinating to watch the bridge move up and
down while a mode in the forward bass corner simultaneously moved exactly
180º out of phase with it. Sound energy is simply transferred back and
forth and is effectively cancelled. A second study done with a soundboard
cutoff appropriately placed removed this area of the soundboard and
increased the efficiency of the whole system.

Del