Hex wire

[Jim Coleman, Sr.]

Hi Dave:

Low inharmonicity is the characteristic of the G. Steinweg and the Fazer
pianos. In general, the hex replacement strings are noted for their high
inharmonicity. Their core is too large in relation to the overall diameters.
The advantage of hex core is that in the thinner strings which use thinner
wrap like .008" diam., the copper wrap adheres better to the core. The
sharp edges of the hexcore bite into the copper.

The S series hexcore replacement strings have smaller cores in general and
as a result give a little better sound. It is still better to keep two
sets of replacement strings and replace both strings of a bass unison rather
than trying to match a hexcore with a woundcore string. It is tough enough
to get two roundcore strings to match in inharmonicity. This is why bass
unisons are so difficult to tune.

It is true that matching the unwrapped lengths of Bass strings is important.
One of the characteristics of the above mentioned pianos is that the
unwrapped ends are short (1/2" or less). This, in and of itself, lowers
inharmonicity.

Low inharmonicity is not always the best as you indicate in your response.
Good matching is better. Small pianos which use wound strings in the tenor
section most always exhibit mis-matching problems. Attempts were made 100
years ago to empirically solve this problem by using separate short bridges
bridges for these tenor wound strings (mind you, this was before we could
even spell inharmonicity). Continuity was lost. I have had some success in
foreshortening wound strings in this area by simply fitting bridge material
in front of the existing tenor bridge area. On a 6'4 Knabe, I was able to
shorten the wound string area by approximately 3" for each note. This 
resulted in raising the inharmonicity of the wound string area to make a
better match with the adjoining plain string area in the tenor section.

Your last question asked if the S and F pianos were designed this way for
a purpose. I believe the answer is yes. For a small piano, the Fazer has
a very clear low Bass, a little reminiscent of the Bechstein and Bluthner
pianos even though it is a small piano with laminated soundboard. The only
unfortunate thing about the Steinweg is that you get the ratching effect
through the bass agraffes as has been discussed in another thread here
recently. I tuned this particular piano for about 8 years and always
worried about strings breaking in the Bass. It never happened on my watch,
fortunately.

Jim Coleman, Sr.

On Wed, 12 May 1999, David M. Porritt wrote:

> Jim:
> 
> What are the inharmonicity characteristics of these pianos?  High IH is not
> bad, mismatched IH is bad.  I know the dimention of the unwrapped end is
> used to control (raise) IH at scale breaks.  Were these designed with this
> wire for some specific scaling purpose?
> 
> dave
> 
> > -----Original Message-----
> > From: owner-pianotech@ptg.org [mailto:owner-pianotech@ptg.org]On Behalf
> > Of Jim Coleman, Sr.
> > Sent: Wednesday, May 12, 1999 12:34 AM
> > To: dporritt
> > Cc: pianotech@ptg.org
> > Subject: Re: Hex wire
> >
> >
> > Hi Dave:
> >
> > There have been several pianos over the years which have used hex core
> > thoughout the bass section. A notable good example is the Fazer (Fahtzer)
> > piano made in Europe. I have seen 7'4 Grotrian Steinweg pianos with hex
> > core. Nice sound. In the 50's Gulbransen made 6' grands with hex
> > core bass.
> >
> > Jim Coleman, Sr.
> >
> 
>