To be or not to be: a heavy hammer

Richard Brekne Richard.Brekne@grieg.uib.no
Wed, 16 Oct 2002 19:25:10 +0200


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David Love wrote:

> Several Points: First, the issue, as I mentioned, is not
> whether a 5g hammer can replace a 10 g hammer, but whether
> you reap any benefit from going from 10 grams to 12, or 5
> grams to 7 grams grams.  I'm not arguing "light hammer", I
> aim for medium zone strike weights: 10.5 - 11 g at note
> 1.  I am arguing against going to overly heavy hammers,
> high strike weight zone type.

I understood this David, of course we are talking about 1 to
2 gram differences. What I dont see is that there is any
real qualification for saying that SW's that fall into the
Stanwood (I assume that's what you are referring too) high
SW zones are, as you say, "overly heavy".  Such hammers can
certainly be made to function well in an action, either with
or without assist springs. Indeed one does not require any
particularly low ratio levels to regulate quite normally
until one approaches the highest levels of the high SW zone.
Nor does any of this require abnormally high levels of FWs.
I daily see pianos off the factory line with much higher
levels then the balance equation results in for this level
of SW.

It is my view that this particular piece of the discussion
is a matter of taste more then it is anything else. I doubt
that you are suggesting that a 2 or even a 1 degree
difference in SW across the board will  result in no
significant difference in sound or touch.

 Second, the differences between hammer #88 and #1 include
other things besides weight: the amount of felt over the
core being a significant factor.   Also, as I mentioned, if
there is too great a difference in mass, then you won't be
able to achieve enough of a difference in velocity to
compensate.

Of course the extremeness of the example was meant to point
exactly out that there is much more going on then simple
velocity/mass relationships. And to be frank, I have not
seen anything that shows that this concept of mass
compensation is entirely valid. If anything our experiences
with Ed's philosophies point in the opposite direction. I
would personally be surprised if even a half gram difference
across the board in SW would not be noticeable. And indeed,
the clip weight experiment bears this out. Whether you like
the sound or not is a different matter entirely.... and
falls within the realm of personal taste does it not ?
 Third, if the lightest you can play with control is with an
acceleration of x, then the quietest the piano can be made
to sound becomes a function of the mass of the hammer (una
corda aside).  Though the same thing is true at the other
end a properly voiced piano includes the ability to push the
volume to the point of distortion (in case you want that
effect) and so you don't benefit as much there.  I admit
this is a small point of consideration.
But no one has shown that the lightest you can play with
control is the same for every hammer mass, nor which one is
more controllable then the other. The lowest controllable
hammer velocity in our instrument is largely dependent upon
the ratio used. And a lower ratio will mean a significant
reduction in velocity as well. Further we have the problem
of SW to SWR. I have not heard it said that hammers in the
Low Mid range or below match to well with ratios of less
then 5.7, certainly not 5.3 or lower. If you use then 5.7 or
above to match your light hammers, you also increase
acceleration. You may not be able to achieve the same
controllable low force with a higher ratio lighter SW match
as you can with a lower ratio higher SW match.
 Fourth, a high strike weight zone hammer requires either
more lead or lower action ratio, or assist springs.  I think
actions can be optimized in terms of inertia and action
ratio.  I don't like FW's up at the maximum.  I prefer them
at about 80%.  I think it gives a better feel.  Action
ratios should be where regulation specs are not
compromised.  Though blow distances vary on certain pianos
(though not by much) , I think there is an ideal  range of
dip, 10 to 10.25 mm.   Deeper than that and you start
compromising control, in my opinion.  Though pianos come out
of factories with varying dimensions, it doesn't mean that
those dimensions are ideal.  A hammer of medium weight
allows you to set up the piano with FW's that don't approach
or exceed maximums and with an action ratio that doesn't
force you to shorten the blow or deepen the dip.  I don't
think assist springs offer a benefit in terms of feel or
control.
Yes, but your personal tastes are of no consequence to the
matter at hand. I admit freely I like more moderate mass
levels then some of my esteemed colleagues. Yet that doesn't
mean I can show they are right or wrong for choosing
otherwise. The same really applies to dip and other
parameters. Fact is some folks just plain like a deeper dip
then others, and its our job to identify these preferences
and attempt to find an optimal regulation for that
particular person, not impose some idea we personally have
on these matters. If there is so far, any standard for
optimal control, then the  balance of FW, SW, and R as per
the balance equation must be the best we have seen yet. But
within the scope of what that formula allows, you can allow
yourself quite a wide degree of freedom in the choice of
SW's. Indeed..... that is the whole point. Different mass
levels provide different tonal results. Whatever mass levels
you personally prefer is of course your own affair. SALUT !!
grin. But once chosen, optimal spread geometry first,
followed by an optimization of action balance will result in
a very fine and very even touch and pleasant sound.

Fifth, though rebound is a function of hammer resilience, it
is also a function of mass.  Try your own experiment, put
hammer number 1 at note 60 and see how it sounds.  My
experience is that a high strike weight zone hammer in this
area offers no improvement in tone.  It makes more noise,
but not a better quality sound.

Better is to add lead to the existing hammer 60 to achieve
that same weight. I find that the results of such
experiments agree largely with the exhaustive data compiled
by Stanwood on the matter. That is in part, the basis for
his three SW zones. Outside these zones turns out to be some
combination of limited use, limited workability, or just
plain not popular to the masses of pianists and listeners
who's opinions (vaguely defined as they are) have determined
the range we see out there. Finally, I made these initial
comments because I notice a trend among some rebuilders to
go for high strike weight zone hammers with the idea that
there are tonal benefits to be reaped.  I don't see the
benefits.  Moreover, I see that this configuration requires
compromises in other areas to offset the weight problems
that are created.  I see no benefit here either.  Though
pianists fingers can adapt to anything, I'm not that
interested in trying to push the envelope to see just what
they can tolerate.  I'd rather try and find a theoretical
ideal that balances tone and touch and then make compromises
only when necessary, or to accommodate specific variations
in taste.

I agree that there is a tendency among some rebuilders to
move in the direction of heavier SW's. Indeed I pointed this
out 3 months back or so and got nailed for saying so. Yet I
do not see that there is a basis for saying that this move
results in a compromising of action parameters. Certainly
not a compromising that is in any way to be defined as a
negative. What I DO hear is that different people have
different tastes.... which I already knew about... hehe.
Pianists do adapt... indeed... and what needs to be taken
out of their way  is any unevenness in touch parameters. We
dont need to start imposing some idea about just how much
mass, inertia, or other such issues is enough. Pianists are
simply too different for that. I find Ed preferences for SW
levels workable, and I find Davids high zones equally
workable. They are more different then they are anything
else.
  David Love

Cheers !

--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html


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