Scaling problem

[Joseph Garrett]

The reason they went back is MONEY! It costs less to produce.
Joe
----- Original Message -----
From: "David M. Porritt" <dporritt@swbell.net>
To: <pianotech@ptg.org>
Sent: Sunday, May 20, 2001 2:41 PM
Subject: Re: Scaling problem


> I have tuned one GH1 that was made during a brief time where they had
> wrapped bichords from #26 - #33.  MUCH improved!  Why they ever went back
> to the plain strings there is beyond me.
>
> I measured the inharmonicity on a regular GH1 and #27 had 28.5-cents at
the
> 8th partial - just in case you were wondering why the triple octave (B2 -
> B5) sounds so bad.
>
> dave
>
> *********** REPLY SEPARATOR  ***********
>
> On 5/19/01 at 8:16 PM Ron Nossaman wrote:
>
> >>
> >>     I've had some partial success with carefully doping the hammers,
and
> >> voicing the bass down, plus leveling strings, straightening termination
> >> points etc., but not to any totally satisfactory result.
> >>     Got any good advise? I'm all ears.
> >>
> >>     Or is it just poor design?
> >>
> >>
> >> Kevin E. Ramsey
> >> <mailto:ramsey@extremezone.com>ramsey@extremezone.com
> >
> >
> >
> >Kevin,
> >I'm a long way from being a scaling sage, but I'll vote poor design with
> Joe.
> >The only claims I've heard for improving the problem with voicing are
from
> >Roger Jolly, but he's just blowing steam. Sorry Roger, couldn't help
> myself.
> ><G> A couple of years ago, tuning a GH1B for a dealer, I was tired enough
> of
> >the lousy low tenor that I took a little extra time and got some
> measurements
> >from the piano to check them out on my scaling spreadsheet. I measured
> core,
> >wrap, and speaking length of notes 24-31, with the break being at 26/27.
I
> >found the original break% of #26 at 54%, and #27 at 21%. Tension,
> >inharmonicity, and impedance were just about that smooth across the break
> too.
> >I played around with the scaling numbers at the transition and ended up
> with a
> >reasonable (not good, but reasonable) break with the original speaking
> lengths.
> >I substituted four bichord unisons in the low tenor and it looks like it
> would
> >help. A break% of 54 at #26, and 45% at #27, with a smoother tension,
> >impedance, and inharmonicity curve would about have to help some. While I
> agree
> >with Ron O that this is a far less than ideal configuration, I was
curious
> to
> >see how close I could come aurally. Unfortunately, I don't have a GH1B to
> try
> >it out on, so I can't say for sure what the results would be. My
> impression was
> >that this can't be really fixed with the original bridges, only made less
> bad -
> >and that with more modifications than just changing some strings.
Starting
> at
> >the drawing board, I'd want to put the break at #31 or #32 in the first
> place
> >in a piano this size, but for some reason Yamaha chose a lower point in
> the
> >scale. I didn't see anything particularly obvious to make me suspect
> soundboard
> >problems. It does seem to be the scale that's the primary problem.
> >
> >Now what I want to know, given the obvious wretched sound of these things
> >across the break, where did this scale design come from in the first
> place? I
> >don't see how it could have been "designed" this way and been allowed out
> the
> >door after hearing the results. Who does Yamaha's scaling, and why can't
> they
> >fix this themselves?
> >
> >I don't buy the story that the GH has to sound bad to sell the C at the
> higher
> >price. If it was supposed to sound lousy, they wouldn't be contracting
> these
> >scaling fixes from independent techs.
> >
> >
> >Ron N
>
>
>
>
> David M. Porritt
> dporritt@swbell.net
> Meadows School of the Arts
> Southern Methodist University
> Dallas, TX 75275
>