Unison Flatter than each Individual string?

[Ron Nossaman]

>I believe the right explanation should be approved by
>experiment.with out any experiment,here is my
>assumption for the phenomone:

Baoli,
I explored this some a year or so ago, and found an interesting 
correlation. Very often, taping off the rear duplex of the section 
eliminated the pitch drop when the second string was tuned in.


>if you shift to another partial(meaning you measure a
>different partial of the same note)the rare phomonene
>will probably disapear.Or if you lower the pitch a
>little bit the phomomee should disapera also.

Not all that rare, from my experiments. The pitch rise happened about as 
often as unisons that didn't change pitch - at least in the piano I sampled 
in the shop. I didn't think to try measurement of different partials.


Ron N