1/2 cent difference on unison

[Jim Coleman, Sr.]

Hi Bill:

Yes, you are right about it being faster to tune twice than to tune once.
The results are much more gratifying.

The one thing I do a little differently from you is that I strip the 
middle like you do, but I tune the unisons of octave 5, 6, and 7 as I go.
And also, I reset the SAT sharp by .3 to .5 cents in octave 5 so that the
settled unisons effect leaves the octaves on the safe side. The center of
the piano seems not to have this effect of the full unison being flatter 
than the single string. This is exactly what I did in the Chicago TuneOff
with Virgil plus tuning a little wider stretch in general.

When I used to tune for the Phoenix Symphony, I usually did as Ed mentioned
in tuning the side strings with the SAT and then the middle string by ear.

Jim Coleman, Sr.

On Thu, 29 Jan 1998 Billbrpt@aol.com wrote:

> In a message dated 98-01-29 18:03:33 EST, you write:
> 
> << No, I tune the first string as well as I can, and then I tune the other
>  strings to the first.  The effect is not uniform, and I've decided that any
>  attempt to compensate may actually result in greater error, if in fact
>  there is error in the first place.   >>
> Dear Jim,
> What I do about this is to never create any interval, octave or otherwise
> using a whole unison against a single string.  The last thing I do are my
> middle unisons.  (Once again, different and the opposite of what most people
> do).  Everything else in the piano is already done, treble and bass.  That
> way, aurally or electronically, my octaves are always determined with single
> strings.  If there is a general shift downwards, I figure that the whole thing
> then shifts, like the doppler effect.
>     I do think that sometimes there may be confusion between tuning stability
> and this phenomenon.  Those who insist that using a strip mute will not
> produce a fine tuning try to "raise the pitch and fine tune at the same time"
> as George Defebaugh warned could not be done.  I've always remembered his
> teaching and admonition and find that I can easily tune a piano faster twice
> than I can fight with it once.
>    Anytime you are changing the general pitch of any area of the piano, the
> pitch of a unison will change as you progress through it and beyond it.
>     The coupled motion phenomenon is very real, though.  By doing the test
> that I mentioned, tuning a solid, clean sounding unison, so that it will at
> least be aurally acceptible, stopping the ETD pattern, then checking the
> single string, the single will always roll sharp.  Check the unison as a whole
> again, it will stop the pattern.  I have not tried this on very high notes or
> notes deep in the bass bichords.  It does seem to me though that I have
> noticed this effect while tuning some of the higher bass notes.  I was not
> experimenting, it was just an observation.
> 
> Bill Bremmer RPT
> Madison, Wisconsin
>