Soundboard Thoughts

[Horace Greeley]

Ron,

Good Morning!

At 11:37 PM 12/8/97 -0600, you wrote:
>Yo Horace,

And back at ya'.

>Again yes, and no. From the first day (well, maybe the second) I heard the
>term "bridge roll", I've maintained that it's a *symptom* of soundboard
>failure, not a *condition* of anything. On second thought, I wouldn't rule
>out the fallen arches theory just yet.

Ditto.  Seems(ed) like a buzz phrase, sort of, at the time; and, without
completely ignoring it, also overrated.

>I too have seen/heard pianos that sounded far better than my probably
>debatable diagnostic criteria can account for. I'm just flailing about for
>some very general parameters here. I'm sure there is a whole lot more going
>on than I can account for with a few simplistic "rocks in the ocean" shots.
>One starts, however, by picking up a few rocks.

Problem with acoustics is that even the best acousticians can't 
agree on much.  Basic calculus aside, they can tell you more than
you could ever want to know about your basic empty room.  Then
put in one chair/person/whatever (dare I suggest, a Piano?), and
all that lovely theory goes right out the windows.  I'll entertain
arguments about that position, but, with respect, suggest that
interested parties spend some time looking at how much money
has been spent at places like Carnegie, Lincoln, Kennedy, Davies,
etc. trying to "fix" the acoustics.  By comparsion, look at places
like Symphony Hall in Boston or the Orpheum in Omaha.

>Susan's "thinner ribs" idea was more to negate the effect of centering a
>bridge on the rib by making the rib asymmetric - thicker on one side of the
>bridge, thinner on the other. Good thought, as I stated. My original post
>proposed ever more and thinner ribs and a thinning of the board toward the
>treble to attempt to more nearly match the natural harmonic frequency of the
>board with the note frequency at any given point on the bridge. 

I believe that used to be called a "diaphragmatic" soundboard...
(check the patent drawings).

>"That's no ordinary rabbit!"

"Kill the Wabbit! Kill the Wabbit!"

"OOOOHHHHHH! I killed the Wabbit!"

>P.S. - Cool it with this talk about soundboard compression ridges. If word
>gets out, everyone will want one.

Now, Ron, you know very well that just about all a person has to do
is to buy a new piano.  Chances are, they'll have compression ridges
of their very own, maybe even more than one, if they're lucky,
even before the warranty runs out.

(Ouch!  Who was that masked man.)

Best.

Horace


Horace Greeley

Systems Analyst/Engineer
Controller's Office
Stanford University

email: hgreeley@leland.stanford.edu
voice mail: 650.725.9062
fax: 650.725.8014