ETD Question

[Greg Newell]

Brian and list,
    I swore that I would never do those "me too" posts but this one is well
written and I agree!  You can count me as "me too"

Greg Newell

Brian Trout wrote:

> Hi Richard,
>
> I'm a little late to respond in this thread, and I use TuneLab with David
> Porritt's "Calculate" program instead of Cybertuner, but I'll speak a bit on
> what I've observed with that.
>
> First of all, David Porritt or somebody with a similar background could
> probably give a much more technically accurate account of what I've seen, so
> take what I say with a grain of salt.  :-)
>
> When I take inharmonicity measurements with the Tunelab / Calculate program,
> after taking the individual measurement, I get a little box which has a
> series of numbers representing those inharmonicity levels and the partials
> associated with them.  (Sorry I can't be a bit more technically accurate.)
> I do pay attention to the numbers that are given.  It'll give a list such
> as:
>
> Fund:  0.00
> 1st:  0.04
> 2nd:  0.45
> 3rd:  2.79
> 4th:  4.12
> 5th:  8.49
> 6th:  14.84
> 7th:  19.09
> 8th:   28.66
> and so on, up to the 12th partial or so.  That's only an example from
> memory, and only intended to be an illustration.  Those kinds of numbers are
> what I'm expecting to see.  They usually progress more quickly as you move
> higher in the scale of the piano, and it's harder to get good measurements
> for the higher partials as you get higher as well.
>
> If you get a reading like this:
>
> Fund:  0.00
> 2nd:  0.43
> 3rd:  1.81
> 4th:  24.80
> 5th:  58.97
> 6th:  2.76
> 7th:  11.52
> 8th:  12.84
>
> or:
>
> Fund:  0.00
> 2nd:  1.04
> 3rd:  6.93
> 4th:  26.81
> 5th:  11.77
> 6th:  0.44
> 7th:  4.01
> etc.
>
> ...the program usually doesn't know what to do with those numbers to make a
> decent tuning.
>
> When I've collected all of the IH readings, and performed the 'calculate'
> function, I immediately go to a function called "Graphically Edit Tuning" or
> something similar.  This gives me a screen which graphically displays the
> tuning.  Just from seeing tuning curves from previous tunings, one can get
> pretty good at telling whether a particular tuning will 'work' or not.  When
> the individual numbers line up in a reasonable sequence, usually, they will
> work well.  If they don't, they won't normally give as predictable a tuning
> curve.  (Also, if I just can't get it to do what I want with the
> inharmonicity readings and the Calculate program, I can manually tell it
> what I want by moving sections of the curve or individual notes to my
> liking.)
>
> Some things that seem to matter are, how hard one strikes the string,
> whether the hammers are rock hard, (on a grand shifting the action can
> help<hint, hint>) what kind of scale the piano has, overall condition, room
> noises (air conditioners, kids)... there's a lot of stuff that might affect
> those readings.
>
> With the TuneLab / Calculate setup, if I really can't get a good reading
> with a particular note that's needed, I will try a neighboring note to see
> if one of them will give a more reasonable harmonic layout.  This
> programming will allow those numbers to be substituted for the note I
> couldn't get.
>
> I think TuneLab and Calculate are excellent programs, and I commend Rob and
> Dave both for their efforts.  But by the same token, they are tools, and are
> subject to the skills of the operator.  I often tell my customers, the
> computer makes a great tool, but a terrible master.
>
> There's some food for thought.  Perhaps Dave will have more technical input
> if anyone is interested.
>
> Best wishes,
>
> Brian Trout
> Quarryville, PA
> btrout@desupernet.net