Mechanical Music Digest  Archives
You Are Not Logged In Login/Get New Account
Please Log In. Accounts are free!
Logged In users are granted additional features including a more current version of the Archives and a simplified process for submitting articles.
Home Archives Calendar Gallery Store Links Info
MMD > Archives > January 2003 > 2003.01.03 > 07Prev  Next


QRS Story & Clark Self-Tuning Piano System
By Rob Goodale

I would like to emphasize that I am not biased toward new ideas and
inventive thinking.  On the contrary I have spent much of my life
trying to reinvent the wheel.  As a professional, however, I must
vocalize that this whole concept is ridiculous.

I am a Registered Piano Technician and have tuned thousands of pianos
over the years.  I am a concert technician and also maintain the pianos
for a major university music school.  I am currently planning a
rebuilding business.  I'm not the bragging type, quite the contrary,
but I believe it important to advertise my qualifications in order to
support my position.

Pianos go out of tune for two primary reasons.  The first is the
obvious, playing which gradually knocks individual strings out of their
assigned pitch.  The second and more dramatic are fluctuations
resulting from changes in humidity.  This is an unavoidable factor that
all stringed instruments endure.

Humidity regulating devices such as a DamppeChaser system can be a
significant help, but in the long term this environmental factor always
wins.  In humid conditions the center of the soundboard swells causing
the piano to go sharp.  Conversely in dry periods, the soundboard
shrinks, and the piano goes flat.  Since the more flexible center of
the board is the area most effected, the resulting change is very
uneven, particularly at the bass break, since these strings have
a separate bridge.

There are three factors used to calculate a string's pitch.  All
factors being the same, the more tension the higher the pitch.  All
factors being the same, the shorter the string the higher the pitch.
All factors being the same, the thinner the wire the higher the pitch.
Using these three elements, a formula is calculated to design a scale
for a specific brand and model of piano.

There are three fundamental flaws with the "self-tuning piano" idea.
First, the system is relying on the assumption that there is enough
surplus energy in a string to adjust it by heat to a pre-determined
pitch.  While this theory has a degree of merit, the available tension
on a string is not infinite.

Second, a steel string has limited elasticity.  The strings change
pitch with heat because they are sensitive to this.  Heat can damage
a steel string's ability to maintain flexibility and durability.  This
can be easily demonstrated by taking a very small flame from a match
and holding it under a piano string under full tension.  Without
hesitation the string will break.  While the QRS system does not
concentrate heat in a focused point such as this, damage in the long
term seems clear.

Finally, when the piano is in fact properly manually tuned, the
repetitively heated strings will no longer have a constant reference.
A stable proper tuning will be much more difficult to achieve, and the
cycle continues, (and worsens), with continued "self-tuning".  One
final and perhaps even more relevant point:  How many regular old
fashioned proper tunings would be required to make up the price
justification of a self-tuning system?

Again I stress that this is intended as constructive criticism, I have
more work than I can possibly handle and am not the least bit concerned
about losing my career to self-tuning pianos.  As a responsible
professional, however, it is also my duty to educate my clients on how
to best care and protect their very expensive musical instruments.

Robert Goodale, RPT
Las Vegas, NV


(Message sent Fri 3 Jan 2003, 06:33:11 GMT, from time zone GMT-0800.)

Key Words in Subject:  Clark, Piano, QRS, Self-Tuning, Story, System

Home    Archives    Calendar    Gallery    Store    Links    Info   


Enter text below to search the MMD Website with Google



CONTACT FORM: Click HERE to write to the editor, or to post a message about Mechanical Musical Instruments to the MMD

Unless otherwise noted, all opinions are those of the individual authors and may not represent those of the editors. Compilation copyright 1995-2024 by Jody Kravitz.

Please read our Republication Policy before copying information from or creating links to this web site.

Click HERE to contact the webmaster regarding problems with the website.

Please support publication of the MMD by donating online

Please Support Publication of the MMD with your Generous Donation

Pay via PayPal

No PayPal account required

                                     
Translate This Page