Lo bass tuning

[Jim]

Dear Ted:

Your customer is not without some basis for her assessment of the sharp
sound.  Here is what is going on.  Short tubby strings as others have
pointed out do have very little power in the lower partials.  If you
have followed the writing of Virgil Smith about the whole tone concept
of tuning, you may understand what she is hearing.  Customers usually
do not listen to tones the same way we do.  In fact musicians in general
do not listen like we do.  Here is how the concept of pitch as determined
by the non tuner:

A tone with no inharmonicity would have the following partials or true
harmonics:
                            1st 2nd 3rd 4th 5th 6th 7th 8th 9th
                             55 110 165 220 275 330 385 440 495

The difference between each pair is 55.  These subjective difference tones
reinforce the perception of the pitch of 55 Hz.

Let's say you have a short Bass string on A1(13) which has exaggerated
partials like this:
                             55 111 168 226 285 345 406 468 531

The difference tones equal    56  57  58  59  60  61  62  63

The average of the difference tones is 59.5.  This is the kind of
perception your customer has.  You as the technician must make an
educated guess as to what will satisfy her the best, knowing that she
does not just listen (like you do) to the 6th partial of A1. The SAT
listens to the 6th partial like most of us do and stretches it just a
little lower.

You can see from the above that the subjective difference tones do not
reinforce the pitch of 55 but rather they are all different.  Just as in
a large string section of a Symphony, the violins do not all play exactly
in tune, yet however, there is the perception that you hear a unified
sound.  Their vibrato rates are even different, but when you have that
many playing basically the same note, it sounds good over all.

I could go on and on and on ... but I think you can get the idea from
this much.

Reality is dealing with her reality.  She obviously is a very
perceptive lady.  Of course what she eventually will do is to get a larger
piano which has longer strings and gives a more pure sound if this
pitch thing continues to bother.  You could tune each note of the Bass
to her satisfaction and become a hero, but you wouldn't like the beating
of the lower partials any better than she likes the sharpness of the
lower notes.  I have done this on occasions to the great satisfaction of
my customer.  I just hoped no other tuner would think that I tune that
way all the time.

One way to consistently tune for someone like this is to do 8-4 tuning in
the Bass bottom octave, or even 10-5 matching.  12-6 matching on a small
piano would just be too far out. Find the compromise that works for her.
After all it is her piano and she is paying you.  You can't make a concert
Grand out of it, but you can vary the tuning style if that will please
her.

Jim Coleman, Sr.


On Wed, 8 Jan 1997, Ted Simmons wrote:

> I need some help.  I tuned a Kimball laPetite a month ago using my SAT and
> the customer called me back complaining about the low bass being out of
> tune.  When I got to her house I set up the SAT with the previously
> determined FAC numbers and checked A0, B0,A#0 and C1.  They were right on.
> She insisted that they were sharp.  To prove it she went to C#5 and
> compared it to A#0 and told me that it was tuned sharp and matched C#5. It
> really did sound that way. I took the SAT out of FAC mode and checked the
> double octave, the octave 5th and the double octave 5th against the low
> notes.  They checked out O.K.  It seems that no matter what I did she
> insisted that the low notes were sharp.  So, working on A#0 I told her to
> tell me when she thinks it sounds o.k.   I lowered it to where the string
> sagged and she still called it sharp.  I told her I would place this
> problem on the Pianotech net and see if they can help me out.   Anyone have
> any ideas on what my next step should be?  I'd appreciate any helpful
> comments.
>
> Ted Simmons, Merritt Island, FL
>
>
>