1/2 cent difference on unison

[Jim Coleman, Sr.]

Hi Richard:

If after tuning the unisons of the treble and the 10ths seem slower, try
placing a rubber wedge in a unison to see if the 10th speed increases. If
it does, that is your aural proof that the 3 string unison is flatter than
the single string of that same note. If it doesn't change then you 
merely have the effect of the pitch dropping because you knocked the first
string down in the unison tuning process.

Jim Coleman, Sr.

On Thu, 29 Jan 1998, Richard Moody wrote:

> 
> 
> ----------
> > From: Jim Coleman, Sr. <pianotoo@IMAP2.ASU.EDU>
> > To: Don <drose@dlcwest.com>
> > Cc: pianotech@ptg.org
> > Subject: Re:1/2 cent difference on unison
> > Date: Thursday, January 29, 1998 2:11 PM
> > 
> 
> > 
> > For just a minor correction due to further research. This
> phenomenon of 
> > the complete 3 string unison giving off a pitch lower than any of
> the 3
> > single strings individually is primarily observable in the 5th and
> 6th 
> > octave only.
> 
> Can this be demonstrated aurally? I still on occasion will tune say
> G6, get the double tenth I wanted from D#4, tune out the unison, then
> find my dlb 10th was now slower than the beginning.  The first string
> must have been knocked down a hair when tuning the second string, and
> isn't caught until the unison is completed and checked again.  So one
> learns to tune a little higher... hmm  I wonder...   It would happen
> all the time then, but since you don't tune all of the treble notes
> then it wouldn't happen all the time, and if you do have to tune all
> of the treble notes you wouldn't be fine tuning. 
> 
> Richard Moody  .  
> 
> > 
> > I have measured cases
> > where the difference is as much as .9 cents. Then there are cases
> where the
> > difference is negligible even in that area. I don't think anyone
> yet has a
> > firm explanation for it.
> > 
> > Jim Coleman, Sr.
> > 
> > On Thu, 29 Jan 1998, Don wrote:
> > > 
> > > Who has demonstrated this and how? 
> > > Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.
> > > "Tuner for the Centre of the Arts"
> > > drose@dlcwest.com
> > > 3004 Grant Rd.
> > > REGINA, SK
> > > S4S 5G7
> > > 306-352-3620 or 1-888-29t-uner
> > > 
>