pitch drop :was Virgil's natural beats

[Murray Seminuk]

Hi Ron
This can vary from pianao to piano, but I do see a regularity of this
happening .The two notes on either side of the treble strutt seem to be very
sensitive
to an increase in tension ,and usually need a few passes to settle down.This
is also in the area of the sharpe bend in the bridge(Grand).Do you think
this could have an effect?With a slight humidity change ,this is an area
that is always effected.

Regards
Murray----- Original Message -----
From: "Ron Nossaman" <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: Wednesday, February 14, 2001 9:20 AM
Subject: Re: pitch drop :was Virgil's natural beats


> >We kindof touched on this last year, and were guessing? about sound
> >board/killer octave stuff.  The drop does NOT happen evenly throughout
the
> >scale, and is measurable.
>
> Hi graph man, not entirely guessing. I ran a few experiments that
indicated
> to me it's related to the open back scale. I posted some fairly extensive
> descriptions of what I tried, and what I found. No one has said it
happened
> evenly throughout the scale, but on the basis of my samplings I'd expect
to
> get the effect wherever the back scale is open and long enough. How much
> each note is affected changes from note to note, presumably because the
> speaking length/back scale length/frequencies mix is different for each
> string. That makes it unlikely that the tuner could anticipate the effect
> and pre-compensate on the fly. I don't yet know the proportion or
frequency
> limits, but I haven't abandoned it just yet.
>
> So far, no one else has reported trying the quick and simple experiments I
> posted to verify or refute what I found. I'm still building tools to
pursue
> it further.
>
> BTW, that was Kent Swafford, not Keith.
>
>
> Ron N
>