Weinreich unisons(wasTuneoff)

[Robert Wilson]

--- Richard Brekne <rbrekne@broadpark.no> wrote:
> 
> 
> A440A@aol.com wrote:
> 
> >
> >
> >
> > Greetings,
> >    Gabriel Weinreich (I hope I am spelling it
> right), published  "The Coupled
> > Motion Of Piano Strings" in the late 70's.  The
> gist of his research was that
> > the coupled motion required, at times, that the
> strings not be tuned to the
> > exact same pitch in order to produce the longest
> sustain and clearest
> > sounding tone.
> >    In a short summation,  the coupling of the
> various strings causes them to
> > interact via the bridge.  With two strings, it is
> rather simple, but with
> > three, there can be several overlapping phase
> relationships.  It can become
> > as complex as the salt-spray on the ripples on a
> wave on a swell on the
> > ocean!  If all strings are perfectly matched, the
> energy from the hammer is
> > "dumped" into the bridge, all at once.  The bridge
> moves a lot when this
> > happens, causing the energy to used(transmitted)
> all at once.  The resulting
> > note may be louder at impact, but suffer a loss of
> sustain and bloom.
> >    If the strings' vibrations are hitting the
> bridge in an opposing pattern,
> > they tend to stiffen the bridge against the
> oncoming pulse from the other
> > string.  This stiffening is responsible for more
> of the energy being
> > reflected back into the string, causing the sound
> to sustain longer.   A
> > careful ear can hear the tonal difference in a
> unison that results from very
> > small changes.
> 
> This was a really nice simple explanation Weinrichs
> paper. Since first reading
> this I have wondered many times why no follow up was
> done to look more closely
> into how intervals other then "simple" unisons
> behave an intereract. I aggree
> with  Ed, that a carefull ear can hear the tonal
> difference in a unison that
> results from extreme small changes. I would take it
> farther tho and say that this
> same carefull ear can hear tonal differences from
> similiar manipulation of
> octaves, double octaves and other intervals.
> 
> This lies at the heart of why I use my laptop
> programs less and less for directly
> tuning pianos. I am far from convinced that the
> algorithm that lies at the core
> of single partial CC electronic tuning aids is the
> ultimate answer for ET
> tunings. Or any other temperaments for that  matter.
> Sure they do a fine job and
> create an affect all their own. But it is a very
> singular effect, and the machine
> is not capable of doing anything else, nor of
> solving problems that dont fit into
> that algorithm.
> 
> I also believe that this kind of phenomena lies at
> the heart of what our freind
> Virgil has been trying to describe to us. This
> "blooming" effect of unisons can
> be very "beat-like" to the ear really. At least
> thats how I experience it. And it
> definatly is apparent in octaves and double octaves
> and its' presence in these
> are definiantly  not always coincident with any
> particular calculated single
> partial curve. Which really says that a very
> interesting alternative to the CC
> ETD's presents itself for us to explore.
> 
> I think Bill Bremmers references to the canceling
> affect that different beat
> rates can sometimes have on each other are also a
> part of all this. All in all I
> think there is way to much a tendency to just accept
> that present ETD's
> (verituner not included as I am still not sure how
> it goes about calculating a
> tuning) and the basic approach of single partial
> calulated curves they employ are
> the last word on tuning. There is loads of stuff we
> havent even begun to look at
> yet. Heck thats where all the fun is.... check it
> out... use your ears !
> 
> JAO
> 
> --
> Richard Brekne
> RPT, N.P.T.F.
> Bergen, Norway
> mailto:rbrekne@broadpark.no
> 
> 

This is a curious phenomen, and I have a piano, a
Weber grand, which demonstrates this effect so well. 
If all the unisons are tuned 'perfectly' the resulting
sound after tuning is disappointing, the tone is thin
and not particularly pleasing.  But, after a few days
playing the sound is totally different, the tone is
richer, fuller - the 'bloom' is there (that is a
lovely expression which perfectly describes the
condition.)
The reason, of course, is that the unisons have
altered just enough to allow this wider band of sound
and duration which allows the tone to 'bloom'  But
what are the reasons for this?  Certainly, not all
pianos behave in this way (thank God!) it actually
seems to occur on better quality pianos - does anyone
else find this?

Bob Wilson
London

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