Twangy pianos + stringing

Ron Nossaman RNossaman@KSCABLE.com
Fri, 24 Nov 2000 10:44:22 -0600


><<<<<Over pulling certainly can damage strings, but you do have well
>over 1/4 semitone leeway above pitch
>tension....>>>>>>>>>>>>>>>>>>>>>>>>>>  

>Maybe today we do.  Perhaps
>strings are better manufactured than 22 or so years ago when I was a
>student. However, I still think over pullng is a bad idea.  

Hi Joe,
Me too, beyond a certain point. My point is that you do have a reasonable
amount of leeway for over pulling with chipping and pitch raising without
doing any damage, and you can't tune a piano without pulling something
slightly above pitch. Also, what about those school pianos that were
carefully pulled up to A-440 in February, and are at 445 when you tune them
in September? If you can't go over pitch without damaging the wire, these
pianos are goners. Well yes, all right, I know, they probably are goners,
but not because of over tensioning.


>If there is
>a slight manufacturing anomaly... let's say the wire thins at certain
>points..  the more you increase the tension, the more likely you are to
>cause the wire to thin there even further. And, as the great Dr. William
>Braid White states re false beats, (I'll quote again): "This beating
>arises through segments of the strings being unevenly strained, whereby
>the corresponding harmonics are thrown out of tune. 

Like Newton said, that's unlikely. If a wire under tension is thinning more
in one spot (not section) than it is everywhere else along it's length,
it's already past it's yield point and you need either a new wire, or a new
scale design. With all due respect to Dr White, as Jim B said, you need to
look elsewhere for the answer. That ain't it.False beats are almost never
caused by wire flaws. The first probability is loose bridge pins. Also, the
tensile strength of music wire is higher in the smaller diameters, so if
anything, the treble is more tolerant of over pull than the tenor. Tuners
will routinely pull the high end fifty cents or more over design pitch
without apparent problems. Any ETD users out there care to provide absolute
C-8 pitch measurements (or computed tuning curve extrapolations) on
"normally" stretched tunings as it compares to the presumed 4186 cps in the
scaling software? It might prove interesting to see what we really have there.


>  Again, some of my "twisted"
>logic:  If you won't buy that the likelyhood of false beats developing
>in a string increases with the degree of over pulling, will you at least
>agree that the less a string has been over pulled, the less likely the
>development of false beats? 

First, a belated clarification. Depending on who you're talking to, the
term "false beats" can cover an enormously wide range of nasty string
noises including those caused by duplexes, soundboard impedance problems,
longitudinal mode noises, voicing, string mating, or any number of other
things too painful to list. What I'm talking about here is the anything
from under 1bps, to 10+bps that plagues us in the high tenor and treble.
These are the clearly discernable beats, rather than the fuzzy, very high
rate screamers. These are the beats that technicians attempt to "fix" with
all the bridge pin and string seating tricks. These are the beats that are
attributed to strings riding up bridge pins, twisted wire, kinked wire, and
bridge pins not seated in the bottom of the hole. These are also the beats
that magically evaporate when you touch the bridge pin with something to
keep it from flagpoling in the bridge. String condition has little to
nearly nothing to do with this type of false beat. As far as an over pulled
string being more likely to develop false beats, no, I doubt it. If a
string is damaged in handling or use, the resulting effect is immediate.
It's damaged enough to be a problem, or it isn't. A nicked or otherwise
weakened string will be more likely to break, but it won't sound like a
string that will break next week, or next year, or even in the next minute.
It won't sound any different from the string next to it until it actually
does break. A string that's over pulled enough to damage it will probably
sound damaged immediately, if it sounds any different at all. Again, I
haven't tried this to see what happens. 

My whole point here is that if there are any cause and effect relationships
here they should be definable and obvious after the fact. If it can't be
reasonably demonstrated, then it's suspect. 

Great dinner last night. I can highly recommend the nano-turkey approach to
Thanksgiving eatery. No post holiday three weeks of turkey leftovers to
suffer. Hurray! Hope you had a good one.

Regards, 
 
Ron N


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