Dear All:  I believe that it is well known that older upright pianos show
poor damping characteristics in the first half dozen or so notes of the
treble section.  My own experience is very limited but the three pianos
that I have dealt with all show this problem.  

Upon reflection the reason seems clear to me.  When the hammer strikes
the three strings of the unison many harmonics are generated.  Release of
the key or lifting the damper pedal allows the damper to touch the string
thus stopping the vibration for all harmonics except the one which has a
node at the damper position.  This will continue to sound.  

This is easy to verify by touching the string above the hammer which
immediately stops the vibration.  This is actually used as a technique by
string players when they finger a string without pressing it all the way
to the finger board in order to get harmonics of the open string (the
Flageolet Tones).

I assume that as one goes higher in the scale that the harmonics left
sounding after the damper contacts the string are above the audible
range.  An obvious solution would be to place all the dampers at a
position such that residual vibrations were inaudible.  However this
would require the dampers in the low treble to be placed above the hammer
and would require major redesign of the common upright piano.

I have two questions therefore: 

1. What has been done in modern uprights to cure the problem?
2. How can I improve the damping in an older instrument?

Somewhere, probably in Reblitz's book, I have read that Steinway used 
a more complicated system of damping to alleviate the problem.

Regards
John Johns