action ratios

David Love davidlovepianos@earthlink.net
Thu, 31 Oct 2002 15:31:51 -0800


David S.:

I appreciate you jumping into the discussion.

Actually, my stated preference is for 5.75 ratio with strike weights in the
1/2 - 3/4 medium range.  I find that tonal differences are better addressed
with different types of hammers than different hammer weights.

Though feedback from pianists is important, I think one has to be careful
how it is interpreted.  I have had many conflicting reports from very good
pianists on what they like largely based on what they have experienced up
until now.  If a pianist plays on a 1970's Steinway with an obvious mismatch
between leverage and strike weight, almost anything will be an improvement
and should not necessarily be used as a formula to establish a general rule.
The Steingraeber customer you talk about I am sure loves his piano and would
change nothing.  And I wouldn't dream of changing it under such
circumstances.  But I guess my question is, compared to what?  The problem
with all this is that teasing out all of the variables is almost impossible.
You would need to have two actions that fit into the same piano, same set of
hammers, with the only difference being those variables in question. This is
very hard to accomplish.  I have recently had a very accomplished pianist
give me feedback on low ratio high strike weight design such as you mention
that was very negative both in terms of touch and tone, that was why I was
called in on it.  Though it is easy to simply write all of this off as
"different strokes" I am not quite satisfied with that.  I am looking for a
default set up that can be easily pushed slightly one way or the other.  I'm
not suggesting that the set up you mention is abnormal, but it is somewhat
unconventional.  I don't dismiss it for that reason alone, but if we are
going to depart from convention, then I would like more than a that a few
pianists liked it compared to what they were playing before.  I won't argue
that if a pianist comes to me and says I want top high zone hammers that I
won't accommodate him, but I wouldn't choose it as a default setting.

I will admit that I am skeptical about your reports on action ratios and
regulation specs.  The reason I've chosen 5.75 as a standard default has
everything to do with regulation.  I consider this to be of primary
importance and may differ with you on whether this must sometimes come at
the expense of tone.  I have set up actions down to 5.5 on occasion, but
lower than that creates problems for me.  I can't imagine an action
regulating properly with a ratio of 5.0, even 5.3.  Solving the problem by
adjusting the spread, action center heights simply changes the overall
ratio.  I have played pianos set up with low ratios like this and have found
that they simply required too much dip, shortened blow or both.  A
compromise in the regulation specs can contribute to poor feel as much as a
mismatch between ratio and strike weight.  The piano I mentioned above which
had a ratio of 5.3 and high zone SW's was regulated at 10mm dip/44 mm blow.
It was bobbling all over the place.  The dip required to solve the problem
was not acceptable to the pianist.  One problem in all this is actually
determining what the ratio really is.  Though I find your metrology
extremely useful, I find that its weakest side is in determining the action
ratio accurately.  I presume this is due to the unpredictability of friction
in the process of measuring up and down weight on the same key.  Terry F.'s
recent contribution illustrated this point nicely.  I find direct
measurement to be the most reliable.  I use your system then to verify by
sampling.

The point I was trying to make earlier is that your contribution has been
timely in putting the focus on matching ratio to hammer weight.  The problem
I see is that regulation specs have become a moving target, acceptable in
any range as long as the ratio/hammer weight criteria was met.  Assuming
that there is a relationship between ratio and regulation (I have yet to be
shown convincingly otherwise), and assuming that we consider proper
regulation to fall within a relatively narrow range (which I realize many
don't), then perhaps it is time to reconsider whether a shift in our
priorities at the expense of certain fundamentals is wise.

We can always make improvements to existing situations that will thrill our
customers because of what they have had to deal with up until we made those
changes.  But I think it's also important that we don't mistake their
enthusiasm for our discovery of the holy grail.  We're supposed to know
better.


David Love




----- Original Message -----
From: "David C. Stanwood" <Stanwood@tiac.net>
To: <pianotech@ptg.org>
Sent: October 31, 2002 5:24 AM
Subject: Re: action ratios


Dear Pianotech,

Just some comments on the great discussion that was stimulated by "patent
notice".

David Love states his preference for 6.0 ratio with 1/2 medium StrikeWt.
Stephen
Birkett describes a Cristofori with a 10.0 ratio and, compared with today's
standards,
an almost weightless hammer, (what's the blow/dip?).  I'll state my generic
preference
for a 5.3 ratio with 1/2 high StrikeWt and wippen support springs working
about 11 grams.
What's great here is that we are talking about matching hammer weight with
action ratio
as a means for describing action quality.  It's called Touch Designing and
I'm very happy
to see the discussion progress beyond mere down weight which has nothing
really to do with
the actual force it takes to move a key at playing speeds.

David Love Wed, 2 Oct 2002 Writes:

>The practice of putting heavier hammers on a concert instrument comes
>from the idea that more mass will produce greater force and therefore
>greater volume of tone.

In my case the use of high zone hammers comes from pianist feedback, not
theoretical ideas.  At first I pursued light hammers but listening to
pianists has brought me to explore higher weights.  I'd also like to say
that high zone is not abnormal, it's within the normal zone.  We just
measured
a Steingraeber medium sized grand with upper high zone strike weights and
in the upper melodic section they were above TopHigh.  This piano sounds
absolutely beautiful at all dynamic ranges.  You won't convince the owner
that there is anything wrong with his hammer weight. Steingraeber is one of
the
finest pianos made.  There are countless examples of pianos with high zone
hammer weights in the world that have absolutely beautiful tone there are
some really bad sounding ones too and there are some really good or bad
sounding pianos with 1/2 medium zone hammer weights.  High zone hammers
are not Abnormal.

If 6.0 ratio with 1/2 medium strikewt works for David Love he should pursue
that.  There are pianists who will like that style of design.  I find that
ratios closer to 5.3 with high zone strikewts work well for my clients.
What's important is that we are talking about hammer weight and ratio.  This
discussion was missing in the past.  It's great!

I don't impose personal bias on the hammer weights I choose for Precision
TouchDesigns that I provide for my consulting group.  I'm simply getting
feedback from a group of fine technicians that now numbers 58 and they are
listening to the pianists.  It's the feedback that I listen too and base
my touch design decisions on a lot of qualitative input. I'm happy to share
it.

I'd like to relate a real world experience that I had a few years ago.
Serge Harel,
in Quebec City asked me to create a design for a TopHigh zone strike weight
on a
Steinway D concert grand.  I called him up and said "Serge, I've never
designed a
hammer weight so high.  Are you sure?"  His response was "David, I tested
the hammer
weights in the piano and for these hammers with this piano, TopHigh sounds
best".
So I designed an action with TopHigh StrikeWt, 5.0 ratio, and full 88 note
wippen
support springs.  The piano was shown at the NE Regional Seminar and it was
a huge
success.  It plays beautifully at ALL dynamic levels...  Loyd Meyer called
it the
"Magic Piano".  TopHigh StrikeWts have a place in the piano world.

It has also been intimated that ratios as low as 5.5 will cause problems
with
shortened blow.  This is simply not always true.  Hamburg Steinways all
average
5.5 ratios and they are one of the highest standards of quality in modern
pianos.
We have examples of pianos with 5.0 ratios that work with 44.5mm
blow/10.0mm dip.
We have other examples of 5.0 ratio actions that work with a 44.5mm blow
but require
an 11.0mm dip.  What's the difference?  We find that changing things like
action center
heights, spread, hammer bore, knuckle radii, and the magic line can improve
the
efficiency of the geometry.

I've come to measure action efficiency by comparing weight ratios with
distance ratios.
In the above example the action with a 5.0 ratio/44.5mm blow/11.0mm dip is
not very
efficient.  The action with a 5.0 ratio/44.5mm blow/10.0mm dip is very
efficient.

What I teach in my consulting group is to find that best weight hammer for
the piano
then I design the action ratio around that weight.  If the desired weight
is 1/2
medium zone, I would specify 6.0 ratio.  If it's a TopMedium I would
specify a 5.5 ratio.
If the best tone comes from a TopMedium strikewt but the ratio is 6.0 then
the ratio
has to be changed to match the hammer weight and this is done by changing
the capstan
line.  When I hear "Experts" say things like "Never move a capstan line"
It really
irks me.  Moving a capstan line can lead to huge improvements in certain
cases.
We need to develop the skills of knowing when it is appropriate and what
the limits
are.

It's all about balancing the hammer weight and action ratio so it feels
comfortable.
Not too light or too heavy unless the customer specifically asks for
that....

Matching hammer weight with ratio is a skill we need to develop in our
trade.

David Stanwood


Hammer Weight Rating curves available freely at:

http://www.stanwoodpiano.com/touchweight.htm

"When I find an action that is comfortable, the tone is usually too
thin because the hammers are smaller, and so the sound is smaller, too."
Alicia de Larrocha

_______________________________________________
pianotech list info: https://www.moypiano.com/resources/#archives



This PTG archive page provided courtesy of Moy Piano Service, LLC