Weight
& Balance:
or,
"Why is my piano so hard to play?"
You have
probably noticed that some pianos are easier to play, others require
more effort. The reasons for this are various, including softer or
harder hammers, heavier or lighter action parts, newer parts vs. older
ones, the design of the instrument, room acoustics, and even the
weather, but it all comes under one heading: weight and balance.
Most pianists
know that pianos vary widely in touch. But few actually understand why.
Some have noted that newer pianos seem to have stiffer actions, and
older ones that have been played a lot have easier actions. A piano that
has had new hammers installed may now be more difficult to play.
Conversely, one that has had the hammers reshaped or filed many times
may have a feather light action.
Why weight
and balance
is important
If you are
doing a lot of practicing, or playing, or are attempting to become
proficient on the piano, it is important to understand some basic issues
about weight. Too light an action will not enable you to build up finger
strength properly, and will make it difficult for you to subsequently
play on other pianos that may have stiffer actions. On the other hand,
too stiff an action will lead to fatigue, make your practicing less
rewarding, and may ultimately lead to serious muscle injuries, as it
unfortunately has for many pianists. An action that has an inconsistent
weight from note to note will make it difficult for you to learn proper
shading and dynamics, or to play evenly, and will also make it harder
for you to play on other pianos besides your own.
Definition
of weight and balance on the keys and how it is measured
Basically,
weight and balance is very simple: It is the amount of pressure required to depress
a key on a piano. To measure how much, weights are placed on the end of
a key until it begins to go down. Today, piano weight is pretty much
universally measured in grams, but in the past was often specified in
ounces. The ounce is really too coarse a unit for measuring key
resistance (there are approximately 30 grams in an ounce); piano
regulating manuals I have seen from early in the 1900's, for example,
called for a weight of approximately 2 ounces. This is almost 60 grams,
which is a fairly heavy touch. Most piano manufacturers today aim
for a weight of around 50 grams. -Not that they often achieve it on any
consistent basis, however.
When you
depress a key on a piano, you actually are physically lifting the hammer
(felt which strikes the strings) and associated action parts, against
gravity. The part of the key your finger pushes on is designed to travel
downward approximately 3/8". The hammer, however, travels approximately
1 7/8" upward, against gravity. Thus, the hammer travels 5 times as far,
or 5 times as fast, as the end of the key does. This also means that any
weight on the hammer end of the mechanism is multiplied at least 5 times
at the key. I say "at least," because in actual practice this ratio may
range anywhere from 5 to 7 times. (This is actually more true of grand
pianos than verticals; however, in general the same principles still
apply. Vertical pianos tend to have lighter or easier actions than grand
pianos because the hammer moves rather more sideways than upwards when
the key is depressed.) (Maybe we should find another word besides
"depressing" to describe what we do with the keys.)
Note that the
definition of weight above mentions nothing about the amount of, or any,
sound being created for a specific pressure on the key. This type of
weight measurement only gauges the minimum pressure required to get the
key to go down. This is, however, a very useful starting point, called static weight. Dynamic weight, or the actual
pressure required under varying playing conditions, is more difficult to
measure, for it takes into account numerous additional factors that tend
to complicate the equation: how loudly or softly the piano is being
played, how fast certain notes are being played or repeated, whether the
sustain pedal is up or down at the moment, etc.
In addition to
these complications there is an additional one: Human perception. For
instance, two similar pianos may have the same static weight, but one
may give out more sound than the other for a given key pressure, due to
different densities of hammer felt or a number of other reasons. The
instrument that gives out less volume will generally be perceived as
being harder to play, or requiring more effort, because the pianist
"gets" less for what they "give."
Some historical background
Pianos in general have grown
progressively larger and more powerful over the past couple of
centuries, with thicker and heavier strings under higher tension. As
artists over the years have demanded instruments with more volume and
power from piano makers (in order to be able to project to the extremes
of large halls in which they were playing), larger and heavier hammers
(and action parts) have been required to strike the strings with
sufficient force to create that desirable "big tone." This, however, has
created quite a few new problems for pianists, who now have to work
harder to play these instruments.
In recent years certain piano makers
have been manufacturing instruments with even heavier, denser hammers;
and action centers (the pivots on which the hammer assemblies swing)
that are pinned more tightly than was previously considered acceptable.
The objective of moving in this direction was to achieve a yet fuller,
more powerful tone, but at the same time, numerous reports have surfaced
of pianists suffering debilitating muscle injuries after practicing or
performing on these pianos.
Piano makers usually install some amount
of lead in the keys to counterbalance the weight of the hammers,
particularly on grand pianos. In recent years, to compensate for the
additional weight of even heavier and denser hammers, several piano
makers have been installing additional lead in the keys. This alleviates
the problem in one way, but aggravates it in another. Lead will indeed
counterbalance a heavy hammer, but it also adds inertia: actions with a
large quantity of lead in the keys feel sluggish, especially when trying
to play fast repeated notes, trills or in any other situation where the
key has to move quickly.
To address this inertia problem that
results from adding lead to the key, some European and Asian piano
manufacturers use an additional spring in their actions (called a
whippen auxiliary spring). This spring stores energy from the hammer's
return, so that when a key is depressed, the spring, instead of key
leads, helps the key to go down against the hammer's weight. The
drawback to this type of system is that the repetition (or the action's
ability to quickly repeat notes) is often adversely affected since the
spring resists the return of the key (or hammer) to its rest position.
A further contributing factor is that
many brands of U.S., Asian and European pianos arrive new on the
showroom floor with relatively "soft" hammers, as it is assumed that the
felt will pack down where the hammers strike the strings, and become
"work hardened," with playing. The result of the felt becoming
compressed in this fashion is that the piano's tone gradually becomes
louder and brighter over time. If the sound is going to get brighter,
the reasoning goes, then it's better to start with a fairly soft hammer,
as a tone that is a little on the mellower side seems to be more
acceptable to most people than one that is a little too bright.
However, the manufacturers seem to have
overcompensated in many cases; pianists often complain that they can't
get any tone out of the piano: the hammers, they say, are like "cotton
balls" and they must overexert themselves to get any sound at all.
Hammers do indeed "wear harden," or "break in" somewhat with time, but
often not as much as is anticipated, and much of the time nowadays the
piano technician has to help the 'breaking in' process along with a
generous amount of dope or lacquer on the hammers. (Doing this however,
is frowned on in some parts of the technical community: many piano
technicians feel it is better to have a properly made hammer to begin
with, and that the use of lacquer or other chemicals as a stiffening
agent, after the fact, may make the piano's tone brighter, but
ultimately robs the instrument of important expressive capabilities.)
Japanese piano makers, in the past 20 or
30 years, have gained substantial ground over the U.S. manufacturers in
the marketplace, because the Japanese pianos seem to arrive on the
showroom floor better prepared: Hammers are sufficiently hardened to
create a pleasing tone without inordinate effort, and actions are not so
stiff that it is a chore rather than a pleasure to play the pianos.
In 1891, the House of Steinway brought
the the famous Polish pianist Paderewski to America to show off his
playing (and their pianos). In Paderewski's memoirs, he mentions having
problems with the Steinway piano because he was accustomed to playing
European pianos, which had fairly light actions. Compared to those
European pianos, the Steinway had a very heavy touch. Of course, the
Steinway piano also had heavier strings under higher tension than the
European instruments, and was capable of a more powerful tone. But
Paderewski found the Steinway action almost intolerable, because of the
amount of effort required to play it. The problem was ultimately solved
by Steinway providing Paderewski pianos with actions specially
"lightened" or adjusted to his preferences.
Incidentally, this "customizing" has
been Steinway's procedure, and that of other makers of high quality
pianos, for accommodating a number of top-flight pianists over the
years. The bulk of the pianos that go out to the dealers for general
consumption, of course, do not get this special treatment, as it is not
ultimately known who will be playing them, and it is assumed that
adjustments or corrections will be made if the action is not agreeable.
However, as much of this "final prep" is today left up to the dealer,
and as he must pay out of his own pocket, in most cases, to have it
done, it often gets neglected, especially if the customer isn't
knowledgeable about what to expect from the piano, or persistent in
requesting adjustments.
Realistically speaking, it would be
prohibitively expensive for a piano manufacturer to spend all the extra
time devoted to the artists' instruments on a piano that was not
intended for such critical use, or where the person ultimately buying
the piano may not appreciate or even notice all the additional effort
and expense. To do so would probably require that high quality pianos
cost two to three times what they do now, and they are already pretty
expensive. The problem arises, though, when pianos arrive at customers'
homes in a state of adjustment far below the acceptable standard. Most
people who are not experienced pianists, and even some who are, are not
familiar enough with what should be expected, to know when there is a
problem. They may feel like something isn't quite right, but do not
really know where to start, or how to describe the problem. And often,
if the piano's touch is heavier or stiffer than is acceptable, or is
inconsistent from note to note, they simply assume that that is the way
the piano should be; after all, it's supposed to be a high quality
piano, and the manufacturer supposedly knows what he is doing.
This problem is not completely the fault
of the manufacturer. Even if a manufacturer is able to put the piano in
top condition at the factory, different environments to which the piano
will be shipped, the settling of new felts, and the shrinking or
swelling of new wood will inevitably undo much careful factory
adjustment and regulation. It is anticipated that most new pianos will
need re-regulation within a year of being shipped to the dealer.
A certain segment of the piano teaching
profession has, either inadvertently or deliberately, contributed to the
problem in several ways. Piano teachers, particularly, it seems, those
specializing in training child prodigies and competition winners, have
discovered that if their students practice on pianos with heavy actions,
they get a better "workout" and develop more finger strength. These
teachers will often choose or recommend a piano for their students that
has a "stiff" action. Essentially, the piano here is being regarded as a
weight training machine. There is indeed an element of truth to this
point of view, but when carried to extremes can be abused: some teachers
appear to believe that if a little resistance is good, then more is even
better.
It is true that students who do practice
on "stiff" actions generally perform better than students who don't, (at
least for the short term, before muscle injury often occurs).
-Especially if much of the time they are performing on Steinways and
other big-name pianos that frequently have "heavy" or stiff actions. It
is true that it is easier to adjust to a light-action piano if you
have been practicing on a stiff action, than to cope with a stiff one
after practicing on a lighter action (as Paderewski unfortunately
discovered). Since there is virtually no way to predict with any degree
of certainty what kind of instrument a student might find himself
performing on, and since touch presently varies so widely on pianos,
teachers have pretty much resigned themselves to the notion that "the
student must practice on an action stiff enough to allow them to cope
with any instrument they might encounter." As there are some
inordinately stiff and poorly adjusted instruments out there, one can
see where this mentality inevitably leads: students being encouraged to
practice on progressively heavier and heavier actions, and manufacturers
actually requested, by teachers, to produce pianos with even stiffer
actions. These particular teachers, in addition, have developed, and
teach, piano techniques that favor "stiff"-action pianos, and with
which their students often feel "out of their element" on light-action
instruments.
The objective, unfortunately, is to win
the piano competition, not protect the students' physiology. The sad
truth is that several "stiff action" techniques currently being taught
are inherently dangerous; teachers who advocate such techniques later
wonder why so many of their students are experiencing muscle and tendon
injuries. Yet to them, there often seems to be no alternative, given the
current lack of uniformity of weight among pianos.
A complicating factor, though, is that
it takes additional labor and expense for piano manufacturers to
regulate piano actions to the proper weight, and keep them there for any
length of time. New felt installed in the action can be expected to
settle for several weeks or months after leaving the factory. Even
though piano makers have begun to use "breaking in" machines to help
compact new felts, pianos continue to go out of adjustment rapidly due
to felt settling during the first year or two of use, and a piano out of
adjustment is always more difficult to play. On top of this, action
parts installed at the factory tend to be pinned together on the tight
side in order to compensate for future wear; it is assumed that they
will become freer with use. Many times, however, they don't loosen up,
at least not without some help from the piano technician. Another
difficulty, as previously stated, is that there no real way to predict
where a particular piano will end up. Some locations have humid
climates, others dry. Action parts will tend to bind more in humid
environments due to swelling of wood and felt; dry climates tend to have
the opposite effect. And, just like the tires on a car, piano hammers
that are new have more "tread," (and thus weigh more) than used ones
that have many "miles" on them and/or that have been reshaped several
times. All these factors contribute to making a new piano action far
heavier or stiffer than it needs to be.
If the weight on your piano is not what
it should be, or what you desire, weight adjustments can be
performed to make it the way you want. Before doing weight adjustments,
however, checks should first be performed to ensure that the the piano
has been properly regulated (i.e. each note on the piano has been
adjusted to the proper factory settings) and that there are no problems
with the action, such as parts rubbing against each other, or action
centers (pivots or hinges) that are too tight.
Here are some simple tests you can
perform to see whether your piano's weight is within proper limits.
How to
measure weight and balance on your piano:
You don’t need an expensive set of gram weights to measure your piano’s
weight.
You can do it easily, and with as much accuracy, using common coins. For this test you will need a set of gram
weights for measuring between one and 70 grams, or, barring that, a set of
pennies and/or other coins. Below are listed some of the gram weights of
common U.S. coins.
|
COIN
penny (pre 1982)*
penny (post 1982)t
penny (1982)t
nickel
dime
quarter
|
WEIGHT
3 grams
2.Sgrams
May be either 2.5 or 3 grams
5 grams
2.5 grams
5.5 grams
|
*Apperently sometime in 1982 the U.S.
mint attempted to economize on the cost of making money by cutting the
weight of it’s copper coin % effectively getting a free penny for every
five minted.
|
Weight measurements are extremely
useful for a number of reasons. For example, a person may be concerned
whether the touch of a piano is too light or too heavy, or whether it is
even and consistent from note to note, or whether the piano is giving
them a good enough workout to build muscle strength. Finding out a what
a piano’s actual weight readings are can also help pinpoint problems and
conditions that may exist somewhere deep in that labyrinth of 6 to 10
thousand moving parts called the action.
Gram weight sets are available
from piano supply houses. However most of them we tried had
accuracy problems. Weighing them with a pharmacist’ s scale, we
found them to be heavier than marked by as much as five grams per
set. We solved this problem ultimately by drilling holes in the
weights to remove some material.
|
How
to perform the test: Get
a dozen or so nickels. Tape a stack of 6 or 8 together (30 or 40 grams)
and use the rest individually (5 grams apiece) for fine adjustment,
along with a couple of dimes (2.5 each). You can also use pennies, but
the weight will vary according to the date minted (consult chart,
above). Using different combinations of all the coins should enable you
to measure differences as small as ½ gram. For most purposes, however,
an accuracy of within 2 or 3 grams should be adequate.
Depress the right, or sustain pedal, and
hold it down. Place about 50 grams worth of coins or weights on the end
of the key. Do this carefully; don’t inadvertently push down or you may
get a false reading. With light rapping (see inset) the key should
slowly start to go down. If it goes down too easily or quickly use fewer
coins or weights. If it won’t go down at all, or is really sluggish even
with the thumping, use more. You are looking for a slow but steady
downward motion. When you’ve found out just exactly how many coins it
takes, add them all up and figure out the number of grams using the
chart. Don’t worry too much about getting it too exact the first few
times. You will become more adept the more keys (and pianos) you test.
The important thing is to use the same technique for each key (and
piano). In other words, if you thump on one, thump on all of them, and
with the same kind of thump.
|
BREAKING INERTIA
Sometimes it takes a little extra
help to get the key moving to begin with. Many piano technicians,
when measuring touchweight, will thump or rap the piano under the
keybed with the fist or palm of the hand. Other technicians
accomplish the same thing by playing a key near or next to the one
being tested. This may seem to some people like rrcheaungrr
-yielding a reading that is actually afew grams less than what it
really takes to depress the key. However, in real flfe piano
playing the depressing of a key is usually accompanied by a wealth
of vibration from strings, soundboard, pedals and other keys being
played, so there may be legitimate reason for this practice.
|
A reading of 50 grams is about standard.
Depending on the piano, however, it may be considerably more or less,
anywhere from 30 to over 70 grams. Note that the key may not go all the
way down. That's O.K. There are additional factors that come into play
when the key is about halfway down, and we are not really concerned with
them here.
Actions measuring an average of below 45
grams per note would likely be considered "light." Actions that "weigh
off" at 55 grams or above are generally considered either "stiff" or
"heavy." (And sometimes a little of both.) Both excessively light or
excessively heavy actions will be more difficult to control than a
properly weighted action. Sometimes a single piano will exhibit both
conditions: a weight that is too light on some keys and too heavy on
others. Consistency is important: a difference of more than a couple of
grams between neighboring keys can be felt by most pianists.
Weight is usually measured with the
sustain (or right) pedal depressed, to take the weight of the dampers
out of the system. If you desire, you can also measure how much
additional weight the damper system adds. (If you do, however, remember
that the dampers do not come into play until the key is at about 1/2 of
the way down, unless they are out of adjustment) But for now, keep your
foot on the pedal.
You will need to test several keys to get a
fairly good idea of where your piano’s weight and balance is, and, of
course, the more keys you test, the more accurate your results will be.
In our shop, we routinely weigh off every key for up weight (see below)
as well as down weight. The two measurements are then used in formulas
to help pinpoint problem areas.
UP WEIGHT
Up weight is the amount of weight the key
will lift back up from it’s depressed position. This measurement, along
with the "down weight " measurement, can help us pinpoint weight
problems, such as whether an action is sluggish because of binding parts
(friction), or whether it's hard to play because some of the parts (like
hammers) are too heavy.
With the key in it's "down"
position, see how many grams you can place on it and still have it
return to it's "up" position. (Keep the damper pedal depressed; if the
weight of the dampers are helping the key to return you will get a false
reading) Usually this measurement should be around 20 grams (or about 4
nickels).
For comparison, Steinway
specifies that for their Models S, M & L pianos, the down weight
should taper from 50 grams in the low bass to 47 grams in the high
treble, and the up weight should be at least 20 grams. This would
yield a difference of between 27 to 30 grams.
Note that it is O.K. in their book
to have an up weight higher than 20 grams, but not lower. A higher
up weight means a faster key return, and, for a given down weight,
less friction. There are practical upper limits, however. It is
possible to have too little friction in an action. When there is
too little friction, parts become loose, wobbly and don ‘t do
their job as well. Typically there will be a range of acceptable
friction, for a given piano, depending on a number of different
factors, including who ‘s playing the piano and what they’re used
to.
|
If
there were no friction, up weight and down weight readings would be
virtually the same. The difference in the readings is due to friction in
the moving parts. When you depress the key, you have to overcome both
friction and the weight of the moving parts in order to lift the hammer.
When you release the key, friction is still there, offering
resistance now against the key’s return. Friction isn’t particular:
it works in both direction. The weight of the hammer, on the other hand,
wants to go in one direction only: down, toward gravity. These unique
qualities of friction and weight allow us to separate the two. The
difference between the up weight and the down weight can be
therefore be regarded as a representation of the amount of friction in
the action.
For now, it is not necessary to understand
where all the friction comes from, but only that there are acceptable
and unacceptable amounts, as far as the pianist is concerned. It is
normal for a piano to have a certain amount of friction. Usually 20 to
30 grams difference between up weight and down weight readings
is considered "normal."
In general, readings can be interpreted as
follows: If the difference between up weight and down weight is high (i.e. more than 30g) there is probably excessive friction
somewhere in the action: some parts are probably too tightly pinned or
something is rubbing. If the difference between up weight and down
weight is low (i.e. less than, say, 20) it probably means the
friction is low: some parts may be loose or worn, or need re pinning.
If down weight and up weight are both high
(i.e. down weight over 50 and up weight over 20) it usually indicates
there are some heavy parts in the action somewhere, (often the hammers).
If down weight and up weight are both low (significantly under 50 and
20, respectively) it usually means the action parts are light: the
hammers may have been replaced with new, undersized ones, or may simply
have been filed many times. This latter condition is often found on
older pianos, along with old, loose, worn pivots, accounting for their
“light, effortless feel.”
The following tables should help you see
the relationships between up weight and down weight.
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