Harmonic Distortion / Overdriving strings?? Noise Question???

[Ron Nossaman]

At 08:45 AM 3/7/99 -0500, you wrote:
>Thanks Mark and Ed both, and Ron too.
>
>Actually, the very first thing I tried, was doing a thorough string level /
>hammer travel / match the hammers to the strings... and it did help... a
>little.  The sound was more pure and there was a lot less garbage in there,
>but... that noise was still there, strong as ever!  I tried needling the
>daylights out of hammers.  It helped.  But if I hit those same keys a little
>harder, there it was, the same noise.
>
>Ron put up an e-mail which got me to thinking.   Soundboard impedance.  This is
>one I'm going to have to study a bit.  I haven't paid much attention in the
>past, but I think it's time.  There were several Boston pianos that went back
>to Steinway last year to put new soundboards in.  Some kind of problem with the
>'tone', or "they just don't sing", if I recall.  Perhaps the Kawai soundboards
>(that's who makes Bostons) are quite different from Steinways???
>
>Again, thanks for the thoughts.  I appreciate the input.
>
>Hope you're all having a great weekend.
>
>Brian Trout
>Quarryville, Pa.
>
>Mark Bolsius wrote:
>
>


Hi Brian,

The clue here (and almost anywhere else you might look) is that every piano
you tried had the same problem in the same area of the scale. Why would they
all have hammers that are problematic in the same narrowly defined section
of the scale? Doesn't make sense. Why would ANY set of hammers have this
problem in just this particular section or the scale, when the set is cut
from a continuous piece of felt, much less ALL of those you checked? Again,
it doesn't make sense. They can't all have the same duplex and/or
bridge/capo termination problems because they aren't all built the same. The
one common denominator is the traditional soundboard configuration. It is,
at root, a soundboard design problem. Del has worked out the whys and
wherefores, and can remanufacture a piano that doesn't have that problem.
>From what he's preached to us on the List, and a heaping dose of dumb luck,
I've worked out enough of the basic principals to do something similar.  I'm
now designing and building boards that don't have the killer octave problem.
(thank you Del) Not only that, they don't produce the beloved Steinway
"dink" at the top end. They ring, with better sustain than you might have
thought possible, all the way to the top of the scale. Almost makes you wish
there were more dampers up there. Good - clear - powerful bass, and a
terrific dynamic range through the entire piano, without having to resort to
Voodoo voicing tricks to attempt to disguise the problems, is the result. No
hardener in the hammers - doesn't need it. When the soundboard works, most
of these traditional tone production headaches just evaporate. 

I had a new Boston go back last year too, with the same thing. I hear this
noise in an awful lot of new pianos, but there are only so many battles I
can fight at any given time (considering that hardly anyone believes in this
stuff anyway) so I don't/can't bring it up unless the customer complains.
Then I get to discover that the manufacturers don't believe in it either.
"It's a voicing problem." "Did you try seating the strings on the bridge?"
"We'll see if we can get a *competent* tech to go fix it for them." ----
right. Be prepared for the time the manufacturer takes the piano back and
replaces the board with one that's even worse. That happened to me last year
too, with a different piano, and it's still unresolved.

BTW, you said the Steinway you checked exhibited the problem less than the
others. The next one you check will even the score. Just pay attention and
listen to what the piano is telling you and the patterns fall into place.
Meanwhile, read up on impedance in the Journal and List archives. It's very
enlightening.

 Ron