Pitch drop at A4 ???

[Richard Brekne]

Hi Don... interesting results.. I have also started measuring now.. and havent
posted any results yet as I am trying to work up a good measuring routine. One
that doesnt require so much time, and provides as much information as I can get
for my time.

I did notice one incident of pitch rise also so far. It was an A6 on a Hamburg
S&S "B". Figured there was some thing wrong with my measuring so I didnt dwell
on it at the time so I will have to look a bit closer.

I eventually want get data assembled both on apparent pitch drop due to
coupling, and on this buisness of pitch drop relative to attack. There may be
some relationship between these two when you come to think about it.  Both the
amount of pitch drop occuring during the duration of the string vibration, and
how fast this drops and  compare this to the amount of pitch drop due to string
coupling for each case.

I personally would think that one measurement for each would be sufficient,
contigent upon measureing many pianos over time, an "average" or "tendency"
should show itself anyways.

Richard Brekne
I.C.P.T.G.  N.P.T.F.
Bergen, Norway


Don wrote:

> Hi all,
>
> I decided to take the time to measure a4 at various partial levels. The
> piano was a Young Chang PG-185. A4 was tuned aurally to the limits of my
> abilities. I measured the middle string and then the sum of the three
> strings. Measurement device was Reyburn cyber tuner in *flat* mode--no
> calculated tuning all partials set to zero. I used the measurement feature
> and then *tweaked* it by 1/100 of one cent movements until I was to the
> threshold of the 1/20 of a cent that that RCT is capable of. The piano had
> just been pitch corrected and temperature was 21 degrees and humidity was
> 19%. Each measurement was performed 7 times in  a *rotation* (i.e a4 a5 e5
> a6 c#7 e7 and then back to a4)and the *high* and *low* were tossed out as
> spurious. The remaining 5 were averaged. I attempted to play the same
> volume level at all times. The Pianalyser feature showed six partials for
> this note, and would indicate a need for voicing. (too much fundimental,
> not enough higher partials)
>
> A4 at A4 no measurement difference. (0.06 cents flat of true)
> A4 at a5 pitch was about .5 cents *higher* on the three string unison
> a4 at e5 no measurement difference
> a4 at a6 pitch was about .3 cents *lower* on the three string unison
> a4 at c#7 no measurement difference
> a4 at e7 pitch was about .1 cent *lower* on the three string unison
>
> Humidity dropped to 18% by the end of the test period. Temperature remained
> the same.
>
> Regards,
> Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.
>
> Tuner for the Saskatchewan Centre of the Arts
>
> drose@dlcwest.com
> http://donrose.htmlplanet.com/
>
> 3004 Grant Rd.
> REGINA, SK
> S4S 5G7
> 306-352-3620 or 1-888-29t-uner