F3 check=2.3cent error demonstration

[David Renaud]

I have conducted enough tests now to witness how
very important this error can be. 

Someone asked if this could be demonstrated, inferring
it was
not significant. It is, can be heard, and would be
enough to 
get me fired from some concert venues.

On my first PTG test I made the error of using F3 not
F2.
A4 was in error by exactly 2.3 cents, scoring 83%, a
pass
on pitch, but poor for the concert stage.

I argued, stubborn as I am, that the beat speeds were
perfectly matched and demonstrated....they were indeed
perfectly matched. 
Ah ha.....you used F3, 2.3 cents was no coincidence. 
My examiner, Jack Stebins, measued how sharp the first
harmonic of A4 was relative to the fundamental....2.3
cents.

After the exam asked me to retune A4 aurally using F2
matching
beat speeds. The result 0.0 variance, perfect!
Checking with
F3 the beat speed was too fast because we were
listening not
to the fundamental but the sharper second partial
beat, I slowed
that down to match the speed with the beating fork
speed and 
with perfectly matched beats had a note 2.3 cents off
again. 
This could be demonstrated back and forth repeatedly,
I was
astonished. 0.0....2.3......0.0......2.3.....

If the first harmonic of A4 is 2.3 cents sharp on a
given piano
if you tune perfectly you will compensate with 2.3
cent error.
If the partial is 1.8 cents sharp, perfectly match
beat speeds will be 1.8 cents in error. If this second
partial of A4 on a given piano is 3.1 cents sharp
relative to its own fundamental
perfect tuning, perfectly match beat speeds with F3
will generate
an error of 3.1 cents. We are listening to a wrong
sharper partial.  

It is not a questions of hearing the partials better
or worse, 
not a mater of preference or ease, it is the wrong
partial to
listen and compare altogether and is seriously wrong
to a significantly measurable demonstrable difference.

F3 has no partial at the A4 level, it does at the A5
level. 
Therefore when tuning A4 with F3 we are comparing beat
speeds
of F3 to a forks fundamental with the beat speed of f3
with
A4s first partial(not fundamental). The first harmonic
is measurably sharper then the fundamental generates a
faster beat speed then the fundamental. We will lower
A4 flat by exactly the degree the first harmonic is
sharp to slowing it down
and matching the wrong beat speeds.

It took the desire to upgrade and the test to teach me

the value of this. 

Upgrading made me appreciate many things I took for
granted
before and thought I knew. The current president shook
my hand
and said.....and now it begins.....I did not get it at
the time. 

I am Franky still surprised how many have written in
defending
that using F2 is of little consequence. We can do
better then that.

                                   Dave Renaud
                                   RPT
                                   Ottawa, Canada












	

	
		
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