Wurzen felt - was WEICKERT

Isaac OLEG oleg-i@wanadoo.fr
Fri, 9 May 2003 22:14:36 +0200


adding a few comments
> I have written quite a lot about Wurzen felt on this list
> (and other  e-mail places)  but usually there is hardly any
response,
> despite the importance of this matter. Only a few techs have
responded
> at all and I  suspect it has to do with the difference in voicing
between
> America and  Europe and the use of hammer dopes in the USA.
> In Europe it is not a common practice to use 'soft' hammers
> and then  dope them with a hardener.

We even try to avoid the refelting of hammers because use of dope is
then sometime unavoidable.

> I personally prefer a hammer with as little hammer dope as
> possible.
> Why? because hammer dopes kill the natural elasticity in
> the fibers, thereby definitely changing certain 'lively' aspects in
a tone.

If we look at the ESTONIAN piano site, they produced a machine to test
the springiness response of the hammers,. see
http://www.cs.ioc.ee/%7Estulov/music.htm

where it is said : "A piano hammer is a rather complicated object.
First, relationships of dynamic force versus hammer deformation show
the significant influence of hysteresys, i.e. the loading and
unloading of the hammer are not alike. Furthermore, the
force-compression relationships of the hammer are essentially
nonlinear, and the slope of the dynamic force-compression curve is
strongly dependent on the hammer velocity."

A model of the hammer that takes into account all the dynamical
features of the hammer was derived in the paper: A. Stulov,
"Hysteretic model of the grand piano hammer felt", J. Acoust. Soc. Am.
v. 97 (4), 2577- 2585, 1995.
According to this model the piano hammer possesses history-dependent
properties or just, in other words, is made of the material with
memory. In this case two additional hereditary parameters are involved
to describe the hysteretic behavior of the hammer. "

They produce a nice setup shown on the site that allows to test the
characteristics of hammers -

I don't pretend understanding clearly what is expressed there, but the
fact that the piano hammer felt is remembering the way it was treated
(from the start probably) and react accordingly all the time it is
used is well adding a bit of water to what says Andre about the
"definitive" first voicing.

Nowadays some of these characteristics are lost when lacquering is due
for a reason or another, in many factories lacquering a serial of
hammers mean calling the Renner factory an ask what the hell is going
there !

> In the past all the hammers of the great European builders
> were covered  with a felt that was lively, with very elastic fibers,
but
> yet firm and  with a very satisfying tone. On some older untouched
Steinways,
> Bechsteins, Schiedmayers, Blüthners and Bösendorfers we may
> still find  this marvelous Wurzen felt.

The name of the felt was WEICKERT in this time (name of the factory)
it is also seen on old Pleyels, Gaveau or such French pianos, usually
a stamp on the first bass hammer side.
from the http://www.filzfabrik-wurzen.de/eng.htm<<The company was
founded in 1783 under the name J.D. Weickert. Later, the company
became world famous for its legendary piano felts under the name of
J.D. Weickert Pianoforte Felt Factory. Today, the company is the
oldest existing felt factory in the world. After Germany reunification
in 1989, the company was renamed Felt Factory of Wurzen Ltd. (FFW) and
re-privatized by Klaus Brand in 1991 with a firm commitment to its
long standing tradition and future.


> It is not too hard and not too soft and thus requires both some
> needling and hardener in the extreme treble and bass.
> If I understand it well, Americans just work the other way
> around : a very soft hammer, to be hardened to the right level of
> crispness and  hardness with 'a' hammer hardener.
> I honestly think that both the Americans and the Europeans seek the
> same kind of tone but in a different way as they both have
> different  traditions and backgrounds.

I believe a little differently that because of our slightly different
musical culture and environment the tone we are used to is a bit
different - may be we could try to say that we aim in Europe for a
tone that is supposed to be build by the pianist (and the tuner !)
while another approach is to give a ready to use tone, that can be
played with more or less volume, but where the most of the coloration
is given by the strings/soundboard, the hammers having lesser a role
in the story.
I've heard that a very good concert piano played by a brutal pianist
can be awful to the point I wandered if the piano was properly tuned,
while after that played by a sensible and experienced artist it singed
and was mellow.

> Anyway, Abel hammers are louder because the felt is much
> more dense and Abel does not share the preferences Renner customers
have,
> whereas the  Wurzen hammers produced by Renner are more open
structured
> and require  less needling. The sound between the hammers produced
by these
> factories is completely different.

I really find not much "body" in the tone provided, but they have a
brilliant quality that can pleases some who like brilliance I just
noticed that the density is not easy to turn in mellowness or tone
power. I've heard they aim for kind of "pre voiced" hammers, not sure
I understand ...

> I have my own rather strong opinion but I certainly wish to
> respect the  preference of people who have a different opinion.
> There are many different wines so to speak, but I was just
> wondering  why so few technicians react to this issue as it actually
one of the
> very aspects of our trade.....

I too have much respect for any way some can like the tone he likes, I
just wish to have more material to listen, so I could compare and have
a better idea on what is where.

I've listened to a Chickering grand (in a poor state) lately, and it
certainly could have been a very musical instrument, probably more
near of the Viennese tone than the German one way less of a percussive
instrument than many.

I suspect that the treatment of the attack and the percussive part of
the tone is what differ mostly in the way we listen and appreciate the
tone of the instruments. Experiences have shown that if we listen to
piano tone without this attack they hardly are recognized by the
listeners.
I suspect also that non hardened hammers, softer or harder, are more
prone to give more coloration than lacquered ones, probably because of
more variation in the excitation they can provide to the acoustic
system (strings/board/rim/etc)

Pfff.....


With much respect and best wishes to all colleagues.

Isaac OLEG




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