unisons by ear or machine

[Jim Coleman, Sr.]

Hi Richard:

For quite some time I have been tuning unisons (each string) using the
SAT III, RCT and TuneLab. The amount of change of pitch is negligible
in the middle of the piano. The main area where this is noticeable is
in the area of the 5th and 6th octaves. Since I habitually stretch
the octaves in the 5th and 6th octaves, the 5ths are not affected in
any noticeable way.

Jim Coleman, Sr.

On Sat, 15 Jan 2000, Richard Moody wrote:

> "hold the phone" as they used to say in Virginia. Let me get this
> straight.  You tune the individual strings in a unison with the RCT and it
> reads all three strings together as 0.5 cents flat??  That should make an
> audible difference in a Fifth at middle C.  And what does that unison
> sound like to the ear? What happens if you  tune each string in the unison
> by ear and then scope it with the RCT? 
> 	This interesting because I have always suspected that the unison when
> declared "in tune" by two or more technicians might not measure out the
> way theory predicts. I could test Tunelab on this....  ---ric  (has
> suspected wrong before)
> 
> ps.  What happens if you measure from the other side? 
> 
> ----------
> > From: Roger Jolly <baldyam@sk.sympatico.ca>
> > To: pianotech@ptg.org
> > Subject: Re: Counter bearing treatment
> > Date: Wednesday, January 12, 2000 10:05 PM
> > 
> > Hi Ron,
> >            I've done quite a few measurements on the string coupling
> effect. 
> > When an average 3 string unison is tuned for full blush (RCT) on each
> > individual string,
> > 2 strings played together will show about 0.3 cent flat, 3 strings will
> > show 0.5 cent flat.
> > I'm not so sure what the imformation is telling me.
> > Regards Roger
> > 
> > 
> > 
> 
>