THAT MYSTERIOUS BACK CHECK

[DOUG RICHARDS]

     Dear list and Jerry Anderson

     I have had a similar experience with an older grand.  The front rail
     felts looked like they were in "good" condition, but there was
     something it the piano sound quality as well as keyboard feel that
     took me a long time to finally figure out.

     The front rail felts were VERY firm because of the years of pounding.
     There were two symptoms: an indescribable transient shock was felt on
     the keys when the piano was played, and well as an audible "sound"!
     The sound was the most annoying part.  Once the felts were replaced,
     it was like a different piano.  The best I can figure out, the extra
     firm felt allowed the keys to excite the soundboard through the frame,
     and the lack of cushion in the felt changed the feel of how the key
     stopped.

      Although I must admit that I did not take the backcheck height
     seriously at first, now WE MUST STUDY!

     doug
     drichard@qntm.com
     San Jose, CA.

     ps.  My vote was to attach any prior message at the END!  The
     Lotus cc:Mail software I use does this automatically.  This
     provides the reader with the OPTION of reviewing previous posts.

______________________________ Reply Separator _________________________________
Subject: THAT MYSTERIOUS BACK CHECK
Author:  jandy@micronet.fr (Jerry Anderson) at SMTP
Date:    11/9/96 5:55 PM


Dear list,

This backcheck thread reminds me of an experience I had
in the Hamburg Steinway factory that may be in some way
analagous.

Several years ago, in one of the Hamburg voicing rooms
Stephan Knupfer demonstrated to me that he could get
a noticable difference in tone quality in a Steinway D by
changing the front rail felts.  The piano was one of their
circulating concert instruments, only about 18 months
old.  By changing an 18 month old, not visably worn, front
rail felt with a new one (controlling carefully that the touch
depth was not altered), he demonstrated that the tone became
significantly more warm sounding.  He could move the
new  punching from one note to another without my looking
and I could find it every time by it's distinctive sound.

Stephan didn't have an explanation at the time, but after
several years of reflection I tend to believe that the
difference comes from the fact that the percussive impact
of the key against the front key rail (and key bed) is
resonating through the piano body, and is more of a
part of the piano tone then we generally realize.  The
slight difference in changing to a brand new, softer felt
is sufficient to make a change in the total sound!

This is why I take Andre perfectly seriously, and offer
the following hypothesis: Altering the back check configuration
may be changing the nature of a similar impact sound
that is occuring just after the strings are excited, and is
resonating through the key and keybed. I would imagine
that the closer this impact approaches the moment when the
stings are struck, the more it would conribute to the general
power of the instrument.

Anyone buy that?

Jerry Anderson
Paris