SW heresy?

Isaac OLEG oleg-i@noos.fr
Sun, 22 Aug 2004 12:35:31 +0200


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Hi Sarah, thanks for catching on this, I hope this will open a nice thread.
No I look for that old helmet of mine !

Isaac

PS Indeed hammers in the treble does not relate to string mass at all,
certainly for facility reasons.

I recall little have been experimented on the ration hammer mass/unison
mass, but I've heard of some studies .

My questioning is that on some particular designs is not the evening of the
break taking in account the jump in hammer mass and strings mass if exists -
or not ? (even by trial and error)

Bernhard stated that the longer hammers in the bass are less efficient in a
grand and create a noticeable loss in power if compared with verticals,
also. In that regard, adding weight to the first plain wire hammers, should
exacerbate that effect, that was may be the concern I noticed on the
Steinway I talked the weight off (no certitude there, of course, was a few
years ago, many things have changed since then !).

As a tuner/technician, I sometime find more easy to even the heaviness
perception -that is so subjective as linked to tone- working the tone
(voicing and regulation eventually) but we have little mastering of the
basic tonal output power (strings/soundboard/hammer mass), only  how
efficiency these possibilities are employed.

BTW on another subject , I recall having tuned a grand D Steinway to "mask"
or absorb totally the attack noise (it is possible) .

The pianists have find the tone very smooth and even, but it was lacking
power and totally dynamic, and did not allow nuances enough (a smooth
singing tone with little dynamics, not bugly but not interesting for music).

Now I energize the attack so the impact serve tone while it is less masked .
The way it transforms in ringing is where is all the "secret" of a good
tone.

Best regards.

Isaac

P.S I'll be unsubscribing for a while, the list is taking too much of my
time when I participate. I'll be back certainly.

Best to anyone, I wish you a good beginning of the school days.

Isaac







 -
 ----Message d'origine-----
De : pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]De la part
de Sarah Fox
Envoyé : dimanche 22 août 2004 07:31
À : Pianotech
Objet : SW heresy?


Hi all,

Thanks for the advice about techniques to even out the SW curve!  That
should give me a variety of techniques to use/combine in order to even out
the jags.

But the question is one of what my target curve should *really* be.
Hmmmm....  My thoughts:

The unmodified SW curve is obviously very linear.  (Yes, I know what linear
means.  I "minored" in mathematics, sort of -- except that my U. didn't
officially recognize minors).  Stanwood's curves, OTOH, are all concave
downwards.

I was advised off list that I shouldn't force the hammers to artificially
conform to a standardized Stanwood curve but to simply even out the jags to
make the action smooth from bottom to top.  There's something to be said for
this idea.

But as I got to thinking about the SW curves, I was wondering, where do they
REALLY come from?  That is, where does the shape come from?  I suspect the
hammer manufacturing people might be able to enlighten me as to this.
(Ray???)  I'm *guessing* that the felt is denser than the molding, and when
the hammer becomes skinnier, it loses more felt than molding, resulting in a
more precipitous dropoff in weight at the higher end.  This would occur with
a constant hammer length and a linear variation in hammer and molding (and
felt) width.  Am I anywhere close on this idea???

Contrast this function with other functions that might actually relate to
optimal hammer mass:  String length and mass both decrease with the note
number, with a function that is concave upwards.  Note frequency increases
with a function that is concave upwards.  Note period (inverse of frequency)
increases with a function that is concave upwards.  The Stanwood curve seems
rather meaningless with regard to any of these functions.  For instance, it
might be good to match hammer mass to string mass by some proportion.
Right?  As the scale goes up, string length and mass approach an asymptote
of zero.  Therefore, shouldn't hammer mass approach an asymptote of zero?
Instead, the curve starts taking a dive in the treble.  If the scale went up
well past 88, hammer mass would eventually crash to zero.  Because these
curves do not have the same form, the relationship between hammer and string
mass is anything but constant.  That doesn't make sense.

So is this something that is the way it is just because of tradition --
because the cauls are built that way, and that's what ya' get?

Now that I look at my linear SW curve (with jags), I'm wondering if this
isn't REALLY a closer match to something meaningful (like string mass) than
the idealized Stanwood curves.  Any thoughts, y'all?

Peace,
Sarah



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