[pianotech] Steinway A Bass String Rescaling

William Truitt surfdog at metrocast.net
Thu May 21 18:10:58 MDT 2009


To the list:

 

Yesterday, I was at the home of one of my favorite customers, a retired art
professor who spends his days painting.  I particularly enjoy visiting with
him, as he usually invites me up to his studio when I am done tuning his
piano and shares his current work with me, allowing me to free associate
what I am seeing in his abstract paintings.  

 

I rebuilt his 6' 1" Steinway A 9 years ago.  I put in a new block and
restrung it, and rebuilt the action with new parts.   This was the second
rebuild for the piano, as the soundboard had been replaced 25 or 30 years
before (but the block had not).  

 

It is a rebuild that I was particularly happy with, and he seems to enjoy it
very much.   One of the notable improvements was in the bass - definitely a
better sounding bass than the original, to his delight and mine.  

 

This piano is of particular interest to me, as I have the same model
Steinway A in my shop right now.  So I was looking at the things I felt I
had done right on the first piano, with the hope of bringing some of that
success to the current project.

 

As I was tuning the piano I was musing as to why the bass sounded so good.
If my memory serves me, the strings were GC strings from Canada.  They have
always been very clean sounding and resonant strings for me, and this piano
was no different.  So I wondered if there was anything different about the
bass string scaling.  As it turns out, there are some differences that may
account for the improvement in tone.

 

Below are measurements for the A0 string, as calculated in PScale

 

Piano                                    Inner Dia.            Outer Dia.
Wraptype           Inharm.                Tension                Breaking
Percent                Waste Length A                Waste Length B   

 

My original                          .061                        .206
single                    .279                        205.872
21.886%                               18 mm.
18 mm.

 

His rescale                           .053                        .220
double                  .137                        233.955
32.946%                               12.7 mm.
12.7  mm.

 

Differences                        -.008                      +.014
-.142                      + 28.083               +11.060%
-5.3 mm.                             - 5.3 mm

 

 

 

It seems apparent that several things have taken place.  The string maker
decreased the core wire size by .008, increased the wrap by .014 and made it
double wrapped, and shortened the waste lengths.  Collectively, this
resulted in a substantial drop in inharmonicity.  This may, in part, account
for the increased clarity of the string.  The tension went up 28 lbs., which
increased the breaking percentage by 11 percent.  I believe this is
meaningful, as the very low breaking percentage of about 22 percent on the
original.  The larger wrap with a higher breaking percentage sounds crisper
and leaner.  The bass sounds big for its size.   This may or may not be
related, but the sustain all the way to the bottom continues to hang on
(unlike most pianos this size, where the sound begins to get choked as you
drop further into the last half octave).  I wonder out load if this
excellent sustain is a result of this scaling change.

 

My feeble memory seems to recall that, some months ago, there was a
discussion of bass string scaling.  Someone (it may have been Ron Nossaman)
made the comment that the core wire size on the particular model Steinway
being discussed was too large.  Of course, this would seem to speak to the
information I am sharing here

 

Those of you on the list who have engaged in bass string rescaling along
these lines, I would most appreciate your comments and your observations on
the aural  benefits derived from such machinations.

 

Thanks in advance,

 

Will Truitt

 

 

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