Formulae & SATs

[Jim]

Hi Jim:

I just tho't I'd chime in here with a bit of explanation. When you take
numbers from the SAT, it is good to remember that the partial the machine
listens to is usually not the fundamental until you get to C6.  The number
10.4 which you had for A4 is for its 4th partial.  The number 9.0 for A5
is for its 2nd partial.  At first glance, one would think that the A5
in this case is flatter than the A4.  Not so.  This shows the 4-2
relationship of the octave ie an aural test of F4-A4 compared with
F4 A5 actually gives a 10th that is slower than the Maj 3rd, but the fund-
mental of A5 IS sharper than the 2nd partial of A4.  If you continue to
use the normal 3rd-10th aural test for tuning notes above F5, you are
going to have some very sharp beating octaves in that area.  SAT is
predicated upon the idea of having just slightly sharp double octaves in
that area, but the single octave when tested with the 3rd-10th will
show it to be flat.  The proper test for that area is the 3rd-17th test
ie F3-A3 is just slightly slower than F3-A5.  You'll find that this aural
test checks out with the way FAC SAT tunings work.

Any time you want to know which partial the SAT is listening to, just
press the TUNE button (but don't forget to hit MEM button afterward).
If you were to continue tuning in the TUNE mode, the tuning would become
horrible without the proper programmed deviations in MEM mode.  You can
guess how I know.  When was the last time I caught myself doing just that?
Oh, about a month ago.  I hope to get over that when I grow up.

Jim Coleman, Sr.

On Fri, 7 Feb 1997 JIMRPT@aol.com wrote:

> Niklas;
> In a message dated 2/7/97 8:28:11 AM, you wrote:
>
> "" A440 x 2 = (2)A880 + 9cents  TRUE Musically?  (Generic S&S mod 'A')""
> "Just that 9 cents seem very much...I would doubt that.."
> Niklas E>>
> And Richard M. wrote:
> "Thus for the octave A440  -  A880 to be beatless, the A880 would have to be
> tuned to 884.5866832365  cps.  Hmmm   seems high doesn't it."
>
>   You both are correct. I misspoke myself. (I am at the point of the learning
> curve with the SAT that I am dangerous to myself and those around me !)
> What I should have used was the difference between A4 and A5, which is -1.4
> cents and not +9. (9 is the reading for the note A5 and relates to the
> reading on A4 of 10.4 [Right?])
>   Life with the SAT was so simple before this thread was started 'just stop
> the lights'. Now because of this Math thread and posts by Jim C. Sr. and
> others I want to know Why?, How ?, and What If ? Darned BBD!
> Jim Bryant (FL), recovering aural tuner
>
>
>