[pianotech] [CAUT] More Bohemia

Richard Brekne ricb at pianostemmer.no
Sun May 3 12:55:23 PDT 2009


So,  then we are talking about an exact 3:1 after all eh ? :)


    Sorry Ric, but you are completely wrong here. The difference of  my 
    temperament  compared with Gary´s over a telfth is 3:2.998688889
    (without inharmonicity), so that equals to 0,75 cent. That is not
    at  all an academic difference for me.

    Cheers,
    Bernhard Stopper


Hust so folks have it  clear here.  The difference referred to above if 
taken over the D3-A4 twelfth amounts to about 0.575 bps over the entire 
twelfth. This is a simple theoretical difference between what results by 
increasing D3 (without any inharmonicity figured in) by a factor of the 
19th root of 3 vs the 19th root of 6^(19/31). In the former you get 
(using 440hz as D3's 3rd partial starting frequency) 1320 hz for of A4 
fundemental, and in the later 1319.431~  hz for A4 fundemental. Neither 
of these numbers are in real life useful as in real pianos you MUST deal 
with inharmonicity. At the heart of both articles is the idea of using 
12ths as a priority for tuning instead of octaves. Theoretical 
justifications for why one should use the twelfth may vary, but the 
central point remain the same.

Once past the theoretical one comes to the practical... which demands 
using each individuals inharmonicity instead of numbers like those 
above. One matches coincident partials in real pianos to do this. In my 
case, I simply use Tunelab Pocket PC to do this and its easy enough to 
do.  Aural tuners relying on 12ths tests to help in setting octaves have 
ended up in the same basic arena for years, perhaps without knowing it.

Thats as about as far as I'm going to bother going into theoretical this 
and thats. Its about using the 12th and not the octave as a tuning 
priority.... and why that ends up working, and what that exactly does to 
the overall stretch of a piano in comparison to octave priorities.  And 
for that matter how that again compares to Virgils method.

At least thats what its about for me.

Cheers
RicB







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