Baldwin Duplexers, was: Hammer suggestions revisited

[pianoguru at cox.net]

I like the looks of Ron's solution.  I have never tried it, or observed the results, but  I will certainly give it a try if faced with this problem again.

Many years ago, as a university tech, I was frustrated by this problem.  Using strips of key bushing cloth, I muted out the string segments within the termination piece of an SD-10, in the style of a temperament strip.  My intent was to simply make it less painful to tune, and to remove it once the tuning was done.  When the tuning was done, it seemed to me that the treble sounded much cleaner, if not a little weaker.  I decided to leave the mutes in the termination string segments.  The piano was used in a recital hall and later in a choral rehearsal room.  For about a decade thereafter, nobody noticed or complained of it.  If nothing else, it made tuning the beast more pleasant for me.

Years later, I had the opportunity, working at Baldwin, to study this issue further.  I have no solutions to propose from this study, but possibly a better understanding of the problem.  With some sophisticated equipment (obsolete by today's standards) I could take a "snapshot" of the sound of a series of notes.  Plotted on a graph, cascading one note over the next,  one could see the peaks representing the fundament and overtone partials in a regular patterns across the page.  Observing many of these charts, one recognizes the typical pattern, with a occasional  interruption of a renegade peak that didn't belong there.  In the charts of a Baldwin SD, or SF, or in fact, any piano with Baldwin style termination pieces, there was a very apparent and consistent deviation to what one would expect to see.  For every note that was terminated by a termination piece, there was a strong peak that was not related to the harmonic structure of that note, but to a specific frequency.  Each note had a peak very close the the frequency of C-88, whether it be harmonic to that note or not.  It looked as though, no matter what note you struck in the termination piece range, note 88 was stuck simultaneously with it.

Frank Emerson

---- Ron Nossaman <rnossaman at cox.net> wrote: 
> 
> > The jangling duplex is another issue on those pianos and presents 
> > problems no matter what hammer you have.  I have often thought about 
> > removing those contraptions but haven’t come up with a reasonable way to 
> > replace them.  I recall Del Fandrich mentioning something about doing it 
> > awhile ago but I don’t think he elaborated on the list. 
> 
> If they're the individual terminations, this works nicely 
> without modifying or replacing anything.
> 
> Ron N