[pianotech] Pitch Raising

[Joseph Garrett]

Terry and Paul battled away saying: 
" 
> Which Sanderson do you use? With the SAT3 you only have the option of 25%
or 33(?)%. 
 
I use the Sanderson pitch raising method - leapfrogging two mutes, unisons
as I go, A0 to C88. I do not use an AccuTuner. I do use Verituner for
iphone.
 
> In most pianos, for smaller pitch raises I hardly overpull the bass at
all. If it's a big PR (e.g. 40c-50c or more) even then 25% is too much in
the bass. 
 
I agree that 25% would be too much. That's why I've settled on about 16%.
 
> I find that the 33% overpull in the top two octaves or so is oftentimes
not enough. In order to compensate for these, I usually compensate on the
"Msr" by going more flat (treble) or less flat (bass) before having it
calculate the overpull. I re-"Msr" every C#, F, and A (M3's)
 
I agree that 33% would often be too little overpull, which is why I have
settled on about 38%.
 
> I strip mute, A0 - C8, unisons (center, previous note right, current note
left, next note center, etc.) as I go... someday I'll get brave and try a
single mute. Maybe. 
 
I effectively do the same thing, only with two mutes.
 
> I've always been tempted to investigate this, but does it really overpull
that much at the very top? In other words, if I overpull C8 by 33%, what's
to pull it flat, besides the other two C8 strings? Or are the other two
strings enough to drag it back down? 
 
No, of course not. I usually decrease the overpull on the last few notes.
Let's say I'm doing a 55-cent pitch raise - the 38% overpull should be
about 20 cents. I would overpull A8 and all notes below about 20 cents. I
would likely aim for 15 cent overpull on A#8, 10 cent overpull on B8 and
only 5 cent overpull on C8. I also find that I'll decrease the calculated
overpull on the last note or two in the upper tenor and bass. In the low
tenor I will increase the overpull by maybe 10% of the calculated overpull.
And in the monocord section of the bass, I'll usually double the overpull
(about 30%). I just find that these few tweaks usually get me closer to the
ultimate target in the end.
 
Terry & Paul,
Get my pitch raising program, (for SATs), from PTJ article December 1999,
and compare your "percentage theorems with my numbers, do the math and see
how close you AREN"T coming to the real world of pitch raising!<G> I've
done the work. You should try it and see if it's easier and more efficient.
If it works, why question it?<G>
Just my take onall this Percentages crap!
Joe


Joe Garrett, R.P.T.
Captain of the Tool Police
Squares R I