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My Piano Won't Hold a Tune!
My current area of research deals with the topic of string stability
and how to correct this problem to give our clients the most dependable instrument possible.
When
a client spends thousands of dollars on a new piano, they want to do things right…they want to protect their investment.
When they have a technician tune a piano four times the first year as most manufacturers recommend, and even install a complete
Dampp-Chaser humidity control system, they expect their piano to hold pitch reasonably well and be a dependable musical instrument.
When they still have to do pitch raises every single tuning even after a year, it’s not fair to the client. They feel
like they bought a lemon.
A
client that owns a piano with a history of instability will go through piano tuner after piano tuner in search of one that
will do a "good job". They don't realize that the problem may not be the tuner, but the piano. They start to think there
aren't any good piano tuners in their area and eventually lose their love of music. The piano never plays to it's potential,
especially in the realm of stability.
Through Tension Analysis we are able to identify these pianos the first time
we see them. It doesn't matter if the piano is brand new or over 100 years old. The problem I am talking about is
string stability and this problem will not go away by itself. It can be taken care of however in a 1 time
procedure that will last the life of the piano. Let me give you a little background of this problem and where it stems
from in my opinion.
The piano is a complex feat of engineering and physics.
Yet for the most part, pianos are an assembly line item. Manufacturers have a bottom line where they may only spend a certain
amount of time on a piano and still make a profit.
There is a point where the piano is "good enough" say
for 90% of the public and they send it out the door. Even then, the uniformity between pianos can vary widely, even between
pianos with adjacent serial numbers.
Variations can be natural or man-made. Being made of components
we find in nature...i.e. wood, felt, leather, etc... no two pianos will be alike. Changes in environment will have an effect
on the touch, tone and stability of the instrument. Minute changes in manufacturing processes and machining would be examples
of man-made variations.
It is because of these reasons,
all pianos need to be prepped in the store before the sale, or afterwards in the home to bring out the best performance in
the instrument. This is where the technician comes in. If
the store technician is to bring the most out in the instrument, he must be allowed to "prep" the piano and get it ready for
sale.
I have found the problem of string stability in every name brand I have encountered in the last
two years. Sadly enough, not much attention is paid to the area of seating strings, but this is the main cause that some pianos
do not hold a tune. In the past, some of the fine technicians recognized this problem and an attempt they called
"Tapping Down the Strings" was tried with a little bit of success. They knew it helped, even though it improved the stability,
it was not good enough and the piano was particulary unstable for the first few months.
The Solution
In mid 2004 I took this problem head on. After tuning pianos by ear for over 10 years, I started
working with an electronic tuning device that hears with about 100 times more accuracy that we can with our ears. It opened
up new vistas in piano technology for me. The computer gave me more feedback about what was happening to the piano than I
could detect or measure by ear. I could visually see what was going on with the piano and graph what I now call string instability.
This is a graph of a piano's tension after tuning it 4 times the first year (as the manufacturer recommended) and even installing
a humidity control system.
 "Realistically, a pitch difference of a few percent can usually be accommodated successfully during
tuning." This is a separate procedure from tuning and therefore is extra money. You can see where it would be frustrating
having to pay extra on tuning when the piano should be more stable. After all...the manufacturer said... See detailed
information on Pitch Raising.
CLICK HERE FOR: Pitch Raising
The key to identifying string instability on a graph like this is noticing the
large changes in pitch between adjacent notes. A physical test can be performed also for verification.
Since a string is under tension, seating a string properly so that it cannot shift or move
in certain places will change the overall tension of that string. The following is a photograph of strings that were not seated
properly against the plate at the hitch pin. Seating the string by tapping it down against the plate will cause the string
under tension to decrease in tension and become flat in pitch. This change in pitch can be measured. The overall change that
results will be the amount of instability removed from the piano.
There are a number of places that need to be adjusted when seating the strings properly. There is
also a certain procedure that must be followed to get results that are expotentially improved from the "Tap Down Procedure"
that technicians have done for years. These following keys are the critical issues I have developed through computer aided
research in the last two years.
Keys to Stability
1. Change all parts of the string that will move.
2. Make the string travel in a "bee line" (in the shortest possible 3 dimensional route). To make a bee-line, all wire needs to be "helped" when it takes a bend. Whether
the bend is around a hitch pin, bridge pin, or bearing point, whenever the angle of the string changes, there will be slack
that can be removed. Remember helping a wire bend can be in two different dimensions at one time.
3. Cause the least amount of trauma to the overall tension of the
piano by doing half of the piano at a time. This means changing every other string on the piano and then bringing those strings
back up to tension with a pitch raise.
4. Stretch the plain wire strings with a string stretcher. Almost
50% of the total change of a string comes from stretching it. We don't stretch
wound bass strings because it messes up the coils.
This next graph is a picture of the tension after the last pitch raise. It is a great place to start the fine tuning.
The next 4 graphs are from a different piano at various stages of the process.
Even though there are a few individual notes
that are outside a 5 cent range, this next chart shows a very desirable place to start a fine tuning. Most of the
readings are even within the target range. We changed some strings almost 375 cents and in two passes (pitch raises) they
are ready for a fine tuning. That’s impressive!
All pitches are within my target range and additionally within +/- 1 cent. This is fantastic for
a brand new piano. Things will only get better with time as the piano goes through it's "new piano break-in period".
Select the quality and size of video trailer.
Mini-Video 712KB (Fastest download, least detail)
Mid-sized video 8.67MB (Bigger picture, more detail)
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| Picture from this video |
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Other Videos
Video #1 Hitch Pin Area (1:20)
Video #2 Bass Bridge Area
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Video: Single Tied vs Shared Strings
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Reduction of False Beats
Mini-Video 10.4MB (Fastest download, least detail)
Mid-sized video 27.2MB (Bigger picture, more detail)
Gigantic Video 55.5MB (Biggest picture, best detail, longest download time)
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